EP3305936B1 - Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor - Google Patents

Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor Download PDF

Info

Publication number
EP3305936B1
EP3305936B1 EP15893419.0A EP15893419A EP3305936B1 EP 3305936 B1 EP3305936 B1 EP 3305936B1 EP 15893419 A EP15893419 A EP 15893419A EP 3305936 B1 EP3305936 B1 EP 3305936B1
Authority
EP
European Patent Office
Prior art keywords
hot
steel sheet
rolled steel
sulfuric acid
hydrochloric acid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP15893419.0A
Other languages
German (de)
French (fr)
Other versions
EP3305936A4 (en
EP3305936A1 (en
Inventor
Jeong-Bong Yoon
Byoung-Ho Lee
Jong-Hwa Kim
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Posco Holdings Inc
Original Assignee
Posco Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Posco Co Ltd filed Critical Posco Co Ltd
Publication of EP3305936A4 publication Critical patent/EP3305936A4/en
Publication of EP3305936A1 publication Critical patent/EP3305936A1/en
Application granted granted Critical
Publication of EP3305936B1 publication Critical patent/EP3305936B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/84—Controlled slow cooling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur

Definitions

  • the present disclosure relates to a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid and applicable as a material for thermal power plant equipment such as desulfurization equipment, denitrification equipment, preheaters, or parts thereof, and a method for manufacturing the hot-rolled steel sheet.
  • Steels having resistance to sulfuric acid corrosion or sulfuric acid-hydrochloric acid composite corrosion are used as materials for desulfurization equipment and denitrification equipment in thermal power plants in which sulfuric acid corrosion or sulfuric acid-hydrochloric acid composite corrosion is serious, due to sulfuric acid and hydrochloric acid produced by a reaction between moisture and exhaust gas containing sulfurous acid gas and chlorine gas generated when fossil fuels such as coal or petroleum are combusted, pipes of combined cycle power plants, and gas-gas heater (GGH) heat elements required to be made of relatively thick steel sheets, etc.
  • GGH gas-gas heater
  • Cu copper
  • elements such as phosphorus in a range of 0.03 to 0.15 wt%, nickel in a range of 0.1 to 0.4 wt% and cobalt in a range of 0.03 to 0.1 wt% has been added to a steel sheet for resistance to composite corrosion from sulfuric acid and hydrochloric acid as described in patent document KR 2015 0029468 A .
  • copper (Cu) is a relatively expensive alloying element, and thus production costs may be increased in proportion to the amount of copper (Cu).
  • copper (Cu) having a low melting point, may be segregated or easily cause cracks, even if only a small amount of deformation occurs in copper-rich regions. Therefore, cracks may be easily formed in portions such as slab corners undergoing a large amount of processing during a continuous casting process, and thus, surface defects undergoing corrosion earlier that other portions may remain after a hot rolling process.
  • aspects of the present disclosure may provide a hot-rolled steel sheet having high corrosion resistance in a composite corrosive environment containing sulfuric acid and hydrochloric acid, and a method for manufacturing the hot-rolled steel sheet.
  • a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid comprises, by wt%, carbon (C) : 0.05% to 0.1%, manganese (Mn) : 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% to less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb): 0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities, wherein copper (Cu) and antimony (Sb) may be concentrated in a region from a surface to a 500-nm position in a thickness direction of the hot-rolled steel sheet, and the hot-rolled steel sheet may have a corrosion loss of 2.0 mg/cm 2 /hr in 6 hours or less in a solution of 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid having a temperature of 60°C.
  • a method for manufacturing a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid may include: reheating a steel slab to 1100°C to 1300°C, the steel slab including, by wt%, carbon (C): 0.05% to 0.1%, manganese (Mn): 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% or less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb): 0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities; obtaining a hot-rolled steel sheet by hot rolling the reheated steel slab and finish hot rolling the steel slab at a temperature of 850°C to 950°C; rapidly cooling the hot-rolled steel sheet at a rate of 120°C/s to 150°C/s; coiling the cooled hot-rolled steel sheet at a temperature of 650°C to 750
  • the present disclosure may provide a hot-rolled steel sheet having high composite corrosion resistance even though the hot-rolled steel sheet has lower amounts of alloying elements than steel sheets of the related art having composite corrosion resistance to sulfuric acid and hydrochloric acid.
  • the hot-rolled steel sheet of the present disclosure may be used as a material, required to have a relatively thick thickness, for denitrification equipment and desulfurization equipment of power plants, exhaust gas pipes of boilers, and preheaters, and may markedly increase the lifespans of such facilities and apparatuses.
  • the inventors have repeatedly conducted research into compositions of steel sheets and methods of manufacturing steel sheets in order to provide a method of imparting high composite corrosion resistance to steel resistant to sulfuric acid-hydrochloric acid composite corrosion while minimizing the content of copper (Cu) in the steel.
  • Cu copper
  • the inventors have found that if antimony (Sb) is added to a steel sheet as an alloying element, and cooling conditions after a hot rolling process and a coiling process are properly controlled, a Cu-Sb rich layer, guaranteeing high composite corrosion resistance, is formed on the steel sheet to an appropriate thickness in a corrosive environment containing sulfuric acid and hydrochloric acid. Based on this knowledge, the inventors have invented the present invention.
  • Carbon (C) is effective in increasing the strength of a steel sheet. If the content of carbon (C) is less than 0.05 wt%, it is difficult to obtain a desired degree of strength, and wear resistance reduces. Conversely, if the content of carbon (C) is greater than 0.1 wt%, the weldability of the steel sheet markedly reduces, thereby markedly increasing the possibility of defects during welding and decreasing the corrosion resistance of the steel sheet.
  • Manganese (Mn) dissolves in steel and precipitates sulfur (S) in the form of manganese sulfide, thereby preventing hot shortness caused by dissolved sulfur (S) and having a solid-solution strengthening effect. If the content of manganese (Mn) is less than 0.5 wt%, manganese sulfide is not sufficiently precipitated. Thus, hot shortness may be caused by dissolved sulfur (S), and it may be difficult to obtain a desired degree of strength. Conversely, if the content of manganese (Mn) is greater than 1.5 wt%, the above-described effects are saturated, and product cost markedly increases.
  • Phosphorus (P) 0.02 wt% or less
  • Phosphorus (P) is an element inevitably added to steel, and if the content of phosphorus (P) is greater than 0.02 wt%, composite corrosion resistance may markedly decrease from a desired value.
  • Sulfur (S) is an element dissolved in steel causing hot shortness, and thus, the content of sulfur (S) is adjusted to be as low as possible. If the content of sulfur (S) is greater than 0.02 wt%, there is a high possibility that defects will be formed due to hot shortness.
  • Aluminum (Al) is an element inevitably added to Alkilled steel, and it may be preferable that the content of aluminum (Al) be within the range of 0.01 wt% or greater for the effect of deoxidation. However, if the content of aluminum (Al) is greater than 0.1 wt%, surface defects may very likely be formed on the steel sheet, and the weldability of the steel sheet may be decreased.
  • Copper (Cu) is an element added for composite corrosion resistance to sulfuric acid and hydrochloric acid. If the content of copper (Cu) is excessively low, it may be difficult to obtain desired composite corrosion resistance. Thus, preferably, copper (Cu) may be added in an amount of 0.3% or greater. Although composite corrosion resistance increases in proportion to the content of copper (Cu), if the content of copper (Cu) is excessively high, the increase of corrosion resistance is markedly lowered, and production costs may be markedly increased. In addition, surface defects known as star cracks may be formed. Therefore, according to the present disclosure, preferably, the upper limit of the content of copper (Cu) may be set to be 0.5 wt%.
  • antimony (Sb) is a key element for improving composite corrosion resistance.
  • antimony (Sb) forms a Cu-Sb composite oxide in a corrosive environment, thereby effectively improving composite corrosion resistance. If the content of antimony (Sb) is less than 0.05 wt%, it is difficult to obtain the above-described effects. Conversely, if the content of antimony (Sb) is greater than 0.1 wt%, the above-described effects are saturated, and production costs markedly increase.
  • the steel sheet includes iron (Fe) and inevitable impurities in addition to the above-described alloying elements.
  • Fe iron
  • the addition of elements other than the above-described elements is not excluded, it may be preferable that the total content of tungsten (W), molybdenum (Mo), cobalt (Co), and nickel (Ni) be adjusted to be less than 10 ppm. The reason for this is that these elements may deteriorate the properties of the hot-rolled steel sheet, for example, ductility.
  • copper (Cu) and antimony (Sb) may be concentrated in a region from the surface to a 500-nm position in the thickness direction of the hot-rolled steel sheet. These elements are concentrated in the surface of the hot-rolled steel sheet during manufacturing processes, and if the hot-rolled steel sheet is exposed to a corrosive environment containing sulfuric acid and hydrochloric acid, the elements change into a Cu-Sb composite oxide, thereby markedly improving the corrosion resistance of the hot-rolled steel sheet.
  • the contents of concentrated copper (Cu) and antimony (Sb) are not particularly limited. As described below, the contents of concentrated copper (Cu) and antimony (Sb) may be adjusted such that an oxide layer having a thickness of 400 nm or greater from the surface of the hot-rolled steel sheet may be formed in a corrosive environment containing sulfuric acid and hydrochloric acid. If the thickness of the oxide layer is less than 400 nm, it may be difficult to obtain a degree of corrosion resistance intended in the present disclosure. Since corrosion resistance increases as the thickness of the oxide layer increases, the upper limit of the thickness of the oxide layer is not particularly set in the present disclosure.
  • the thickness of the oxide layer is greater than 500 nm, the effect of improving corrosion resistance is relatively low when the addition of large amounts of alloying elements is considered, and production costs may be excessively increased.
  • the thickness of the oxide layer it may be more preferable that the thickness of the oxide layer be within the range of 400 nm to 500 nm.
  • the hot-rolled steel sheet of the present disclosure has a corrosion loss of 2.0 mg/cm 2 /hr or less in a solution of 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid.
  • a steel slab having the above-described composition is prepared and reheated to a temperature of 1100°C to 1300°C. If the reheating temperature is lower than 1100°C, it is difficult to secure a temperature for a subsequent hot rolling process. Conversely, if the reheating temperature is higher than 1300°C, copper (Cu) having a relatively low melting point may melt out, and thus cracks may very likely be formed in the surface of the steel slab.
  • Cu copper
  • the reheated steel slab is subjected to hot rolling, and is then subjected to finish hot rolling at a temperature of 850°C to 950°C, to obtain a hot-rolled steel sheet.
  • finish hot rolling temperature is lower than 850°C, the elongation of the hot-rolled steel sheet is markedly decreased due to elongated grains, and properties of the hot-rolled steel sheet have directional deviations.
  • finish hot rolling temperature is higher than 950°C, austenite grains become coarse, and thus hardenability markedly increases.
  • the hot-rolled steel sheet is rapidly cooled at a rate of 120°C/s to 150°C/s, based on the surface temperature of the hot-rolled steel sheet.
  • the rapid cooling may provide driving force such that alloying elements improving corrosion resistance may move to the surface of the hot-rolled steel sheet after a coiling process. If the cooling rate is less than 120°C/s, the surface temperature of the hot-rolled steel sheet may be too high to sufficiently drive oxide-forming elements from the interior to the surface of the hot-rolled steel sheet, and thus when the hot-rolled steel sheet is exposed to a composite corrosive environment, oxides may not be sufficiently formed.
  • the cooling rate may be set to be within the range of 120°C/s to 150°C/s.
  • the cooled hot-rolled steel sheet is coiled at a temperature of 650°C to 750°C. If the coiling temperature is lower than 650°C, atoms may not easily move during the coiling process. As a result, a rich layer may not be easily formed, and thus an oxide layer may not be formed in a corrosive environment. That is, corrosion resistance may not be sufficiently guaranteed. If the coiling temperature is higher than 750°C, heat recuperation occurs to an excessively high temperature, and thus, defects such as dents may be formed on the coiled hot-rolled steel sheet. Therefore, the coiling temperature may preferably be set to be within the range of 650°C to 750°C.
  • the surface of the hot-rolled steel sheet may have a temperature of 720°C to 750°C owing to a heat recuperation phenomenon.
  • the interior temperature of the hot-rolled steel sheet is adjusted to be within the range of 650°C to 750°C through the cooling process, the surface temperature of the hot-rolled steel sheet is lower than the range because of rapid cooling. Therefore, the hot-rolled steel sheet may be allowed to undergo heat recuperation so as to activate the movement of alloying elements effective in forming an oxide layer and thus to form a rich layer having a sufficient thickness.
  • the surface temperature of the hot-rolled steel sheet may preferably be 720°C or higher after heat recuperation. However, the surface temperature of the hot-rolled steel sheet will not exceed 750°C even if the heat recuperation is sufficient.
  • the coiled hot-rolled steel sheet is slowly cooled to a cooling finish temperature of 350°C to 400°C at a rate of 30°C/hr to 40°C/hr. If the slow cooling rate is excessively high, copper (Cu) forming a rich layer may not sufficiently move, and thus it may be difficult to form a rich layer having a sufficient thickness. Therefore, it may be preferable that the slow cooling rate be within the range of 40°C/hr or less. However, if the slow cooling rate is less than 30°C/hr, the size of grains may increase excessively, and thus, the strength of the hot-rolled steel sheet may decrease. Thus, the slow cooling rate may preferably be within the range of 30°C/hr to 40°C/hr.
  • the cooling finish temperature may preferably be within the range of 350°C to 400°C.
  • Inventive Examples 1 to 3 satisfying the alloying composition and manufacturing conditions proposed in the present disclosure had a corrosion loss of 2.0 mg/cm 2 /hr or less in the sulfuric acid-hydrochloric acid corrosive environment owing to the formation of oxide layers having a thickness of 400 nm or greater. That is, Inventive Examples 1 to 3 had high corrosion resistance.
  • Comparative Example 1 satisfied the alloying composition of the present disclosure, the coiling temperature of Comparative Example 1 was low, 500°C. Thus, an oxide layer was not sufficiently formed, resulting in corrosion loss of 4.5 mg/cm 2 /hr. That is, Comparative Example 1 had poor corrosion resistance.
  • Comparative Examples 2 to 4 satisfied the alloying composition of the present disclosure, the cooling rate of Comparative Example 2 to 4 was low, 10°C/s. Thus, oxide layers were not sufficiently formed, resulting in a corrosion loss of 3.2 mg/cm 2 /hr or greater. That is, Comparative Examples 2 to 4 had poor corrosion resistance.
  • Comparative Example 5 satisfied the manufacturing conditions of the present disclosure, antimony (Sb) was not added to Comparative Example 5, resulting in a corrosion loss of 8.8 mg/cm 2 /hr in the sulfuric acid-hydrochloric acid corrosive environment. That is, Comparative Example 5 had poor corrosion resistance. The reason for this is that a Cu-Sb composite oxide having high corrosion resistance was not formed in an oxide layer.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)

Description

    [Technical Field]
  • The present disclosure relates to a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid and applicable as a material for thermal power plant equipment such as desulfurization equipment, denitrification equipment, preheaters, or parts thereof, and a method for manufacturing the hot-rolled steel sheet.
    • [Background Art]
  • Steels having resistance to sulfuric acid corrosion or sulfuric acid-hydrochloric acid composite corrosion are used as materials for desulfurization equipment and denitrification equipment in thermal power plants in which sulfuric acid corrosion or sulfuric acid-hydrochloric acid composite corrosion is serious, due to sulfuric acid and hydrochloric acid produced by a reaction between moisture and exhaust gas containing sulfurous acid gas and chlorine gas generated when fossil fuels such as coal or petroleum are combusted, pipes of combined cycle power plants, and gas-gas heater (GGH) heat elements required to be made of relatively thick steel sheets, etc.
  • In general, it has been commonly known that a large amount of copper (Cu) may be added to steel having resistance to sulfuric acid-hydrochloric acid composite corrosion so as to decrease the rate of corrosion in a composite atmosphere of sulfuric acid and hydrochloric acid, as compared to the rate of corrosion of normal steels.
  • Although copper (Cu) is more effective than other alloying elements in decreasing the rate of sulfuric acid corrosion, copper (Cu) added in large amounts causes problems such as the formation of cracks in steel sheets during a hot rolling process, and thus, steels to which an appropriate amount of copper (Cu) and other elements are added have been developed (Japanese Patent Application Laid-open Publication No. 1997-025536 , Japanese Patent Application Laid-open Publication No. 1998-110237 , Korean Patent Application Laid-open Publication No. 2009-0070249 , etc). For example elements such as phosphorus in a range of 0.03 to 0.15 wt%, nickel in a range of 0.1 to 0.4 wt% and cobalt in a range of 0.03 to 0.1 wt% has been added to a steel sheet for resistance to composite corrosion from sulfuric acid and hydrochloric acid as described in patent document KR 2015 0029468 A .
  • As described above, although the corrosion resistance of steels resistant to sulfuric acid-hydrochloric acid composite corrosion is improved as the content of copper (Cu) is increased, copper (Cu) is a relatively expensive alloying element, and thus production costs may be increased in proportion to the amount of copper (Cu). In addition, copper (Cu), having a low melting point, may be segregated or easily cause cracks, even if only a small amount of deformation occurs in copper-rich regions. Therefore, cracks may be easily formed in portions such as slab corners undergoing a large amount of processing during a continuous casting process, and thus, surface defects undergoing corrosion earlier that other portions may remain after a hot rolling process.
  • Therefore, there is a need for a method of imparting high composite corrosion resistance to steel resistant to sulfuric acid-hydrochloric acid composite corrosion while minimizing the content of copper (Cu) in the steel.
    • [Disclosure] [Technical Problem]
  • Aspects of the present disclosure may provide a hot-rolled steel sheet having high corrosion resistance in a composite corrosive environment containing sulfuric acid and hydrochloric acid, and a method for manufacturing the hot-rolled steel sheet.
    • [Technical Solution]
  • According to claim 1 a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid comprises, by wt%, carbon (C) : 0.05% to 0.1%, manganese (Mn) : 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% to less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb): 0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities, wherein copper (Cu) and antimony (Sb) may be concentrated in a region from a surface to a 500-nm position in a thickness direction of the hot-rolled steel sheet, and the hot-rolled steel sheet may have a corrosion loss of 2.0 mg/cm2/hr in 6 hours or less in a solution of 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid having a temperature of 60°C.
  • According to claim 5, a method for manufacturing a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid may include: reheating a steel slab to 1100°C to 1300°C, the steel slab including, by wt%, carbon (C): 0.05% to 0.1%, manganese (Mn): 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% or less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb):
    0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities; obtaining a hot-rolled steel sheet by hot rolling the reheated steel slab and finish hot rolling the steel slab at a temperature of 850°C to 950°C; rapidly cooling the hot-rolled steel sheet at a rate of 120°C/s to 150°C/s; coiling the cooled hot-rolled steel sheet at a temperature of 650°C to 750°C; and slowly cooling the coiled hot-rolled steel sheet at a rate of 30°C/hr to 40°C/hr to a cooling finish temperature of 350°C to 400°C.
  • The above-described aspects of the present disclosure do not include all aspects or features of the present disclosure. Other aspects or features, and effects of the present disclosure will be clearly understood from the following descriptions of exemplary embodiments.
    • [Advantageous Effects]
  • The present disclosure may provide a hot-rolled steel sheet having high composite corrosion resistance even though the hot-rolled steel sheet has lower amounts of alloying elements than steel sheets of the related art having composite corrosion resistance to sulfuric acid and hydrochloric acid. In addition, the hot-rolled steel sheet of the present disclosure may be used as a material, required to have a relatively thick thickness, for denitrification equipment and desulfurization equipment of power plants, exhaust gas pipes of boilers, and preheaters, and may markedly increase the lifespans of such facilities and apparatuses.
    • [Best Mode]
  • The inventors have repeatedly conducted research into compositions of steel sheets and methods of manufacturing steel sheets in order to provide a method of imparting high composite corrosion resistance to steel resistant to sulfuric acid-hydrochloric acid composite corrosion while minimizing the content of copper (Cu) in the steel. As a result, the inventors have found that if antimony (Sb) is added to a steel sheet as an alloying element, and cooling conditions after a hot rolling process and a coiling process are properly controlled, a Cu-Sb rich layer, guaranteeing high composite corrosion resistance, is formed on the steel sheet to an appropriate thickness in a corrosive environment containing sulfuric acid and hydrochloric acid. Based on this knowledge, the inventors have invented the present invention.
  • Hereinafter, a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid will be described in detail according to an aspect of the present disclosure.
  • First, the alloying composition of the hot-rolled steel sheet of the present disclosure will be described in detail.
    • Carbon (C): 0.05 wt% to 0.1 wt%
  • Carbon (C) is effective in increasing the strength of a steel sheet. If the
    content of carbon (C) is less than 0.05 wt%, it is difficult to obtain a desired degree of strength, and wear resistance reduces. Conversely, if the content of carbon (C) is greater than 0.1 wt%, the weldability of the steel sheet markedly reduces, thereby markedly increasing the possibility of defects during welding and
    decreasing the corrosion resistance of the steel sheet.
    • Manganese (Mn): 0.5 wt% to 1.5 wt%
  • Manganese (Mn) dissolves in steel and precipitates sulfur (S) in the form of manganese sulfide, thereby preventing hot shortness caused by dissolved sulfur (S) and having a solid-solution strengthening effect. If the content of manganese (Mn) is less than 0.5 wt%, manganese sulfide is not sufficiently precipitated. Thus, hot shortness may be caused by dissolved sulfur (S), and it may be difficult to obtain a desired degree of strength. Conversely, if the content of manganese (Mn) is greater than 1.5 wt%, the above-described effects are saturated, and product cost markedly increases.
    • Phosphorus (P): 0.02 wt% or less
  • Phosphorus (P) is an element inevitably added to steel, and if the content of phosphorus (P) is greater than 0.02 wt%, composite corrosion resistance
    may markedly decrease from a desired value.
    • Sulfur (S): 0.02 wt% or less
  • Sulfur (S) is an element dissolved in steel causing hot shortness, and thus, the content of sulfur (S) is adjusted to be as low as possible. If the content of sulfur (S) is greater than 0.02 wt%, there is a high possibility that defects will be formed due to hot shortness.
    • Aluminum (Al): 0.01 wt% to 0.1 wt%
  • Aluminum (Al) is an element inevitably added to Alkilled steel, and it may be preferable that the content of aluminum (Al) be within the range of 0.01 wt% or greater for the effect of deoxidation. However, if the content of aluminum (Al) is greater than 0.1 wt%, surface defects may very likely be formed on the steel sheet, and the weldability of the steel sheet may be decreased.
    • Copper (Cu): 0.2 wt% to 0.6 wt%
  • Copper (Cu) is an element added for composite corrosion resistance to sulfuric acid and hydrochloric acid. If the content of copper (Cu) is excessively low, it may be difficult to obtain desired composite corrosion resistance. Thus, preferably, copper (Cu) may be added in an amount of 0.3% or greater. Although composite corrosion resistance increases in proportion to the content of copper (Cu), if the content of copper (Cu) is excessively high, the increase of corrosion resistance is markedly lowered, and production costs may be markedly increased. In addition, surface defects known as star cracks may be formed. Therefore, according to the present disclosure, preferably, the upper limit of the content of copper (Cu) may be set to be 0.5 wt%.
    • Antimony (Sb): 0.05 wt% to 0.1 wt%
  • Together with copper (Cu), antimony (Sb) is a key element for improving composite corrosion resistance. In particular, antimony (Sb) forms a Cu-Sb composite oxide in a corrosive environment, thereby effectively improving composite corrosion resistance. If the content of antimony (Sb) is less than 0.05 wt%, it is difficult to obtain the above-described effects. Conversely, if the content of antimony (Sb) is greater than 0.1 wt%, the above-described
    effects are saturated, and production costs markedly increase.
  • The steel sheet includes iron (Fe) and inevitable impurities in addition to the above-described alloying elements. Although the addition of elements other than the above-described elements is not excluded, it may be preferable that the total content of tungsten (W), molybdenum (Mo), cobalt (Co), and nickel (Ni) be adjusted to be less than 10 ppm. The reason for this is that these elements may deteriorate the properties of the hot-rolled steel sheet, for example, ductility.
  • Furthermore, in the hot-rolled steel sheet of the present disclosure, copper (Cu) and antimony (Sb) may be concentrated in a region from the surface to a 500-nm position in the thickness direction of the hot-rolled steel sheet. These elements are concentrated in the surface of the hot-rolled steel sheet during manufacturing processes, and if the hot-rolled steel sheet is exposed to a corrosive environment containing sulfuric acid and hydrochloric acid, the elements change into a Cu-Sb composite oxide, thereby markedly improving the corrosion resistance of the hot-rolled steel sheet.
  • In this case, the contents of concentrated copper (Cu) and antimony (Sb) are not particularly limited. As described below, the contents of concentrated copper (Cu) and antimony (Sb) may be adjusted such that an oxide layer having a thickness of 400 nm or greater from the surface of the hot-rolled steel sheet may be formed in a corrosive environment containing sulfuric acid and hydrochloric acid. If the thickness of the oxide layer is less than 400 nm, it may be difficult to obtain a degree of corrosion resistance intended in the present disclosure. Since corrosion resistance increases as the thickness of the oxide layer increases, the upper limit of the thickness of the oxide layer is not particularly set in the present disclosure. However, if the thickness of the oxide layer is greater than 500 nm, the effect of improving corrosion resistance is relatively low when the addition of large amounts of alloying elements is considered, and production costs may be excessively increased. Thus, it may be more preferable that the thickness of the oxide layer be within the range of 400 nm to 500 nm.
  • The hot-rolled steel sheet of the present disclosure has a corrosion loss of 2.0 mg/cm2/hr or less in a solution of 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid.
  • Hereinafter, a method for manufacturing a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid will be described in detail, according to another aspect of the present disclosure.
  • First, a steel slab having the above-described composition is prepared and reheated to a temperature of 1100°C to 1300°C. If the reheating temperature is lower than 1100°C, it is difficult to secure a temperature for a subsequent hot rolling process. Conversely, if the reheating temperature is higher than 1300°C, copper (Cu) having a relatively low melting point may melt out, and thus cracks may very likely be formed in the surface of the steel slab.
  • Thereafter, the reheated steel slab is subjected to hot rolling, and is then subjected to finish hot rolling at a temperature of 850°C to 950°C, to obtain a hot-rolled steel sheet. If the finish hot rolling temperature is lower than 850°C, the elongation of the hot-rolled steel sheet is markedly decreased due to elongated grains, and properties of the hot-rolled steel sheet have directional deviations. Conversely, if the finish hot rolling temperature is higher than 950°C, austenite grains become coarse, and thus hardenability markedly increases.
  • Thereafter, the hot-rolled steel sheet is rapidly cooled at a rate of 120°C/s to 150°C/s, based on the surface temperature of the hot-rolled steel sheet. The rapid cooling may provide driving force such that alloying elements improving corrosion resistance may move to the surface of the hot-rolled steel sheet after a coiling process. If the cooling rate is less than 120°C/s, the surface temperature of the hot-rolled steel sheet may be too high to sufficiently drive oxide-forming elements from the interior to the surface of the hot-rolled steel sheet, and thus when the hot-rolled steel sheet is exposed to a composite corrosive environment, oxides may not be sufficiently formed. Conversely, if the cooling rate is greater than 150°C/s, the interior temperature of the hot-rolled steel sheet becomes excessively low, and thus heat recuperation may not occur to a desired temperature after a coiling process. In this case, alloying elements effective in forming an oxide layer may not move smoothly. Therefore, preferably, the cooling rate may be set to be within the range of 120°C/s to 150°C/s.
  • Thereafter, the cooled hot-rolled steel sheet is coiled at a temperature of 650°C to 750°C. If the coiling temperature is lower than 650°C, atoms may not easily move during the coiling process. As a result, a rich layer may not be easily formed, and thus an oxide layer may not be formed in a corrosive environment. That is, corrosion resistance may not be sufficiently guaranteed. If the coiling temperature is higher than 750°C, heat recuperation occurs to an excessively high temperature, and thus, defects such as dents may be formed on the coiled hot-rolled steel sheet. Therefore, the coiling temperature may preferably be set to be within the range of 650°C to 750°C.
  • In addition, during the coiling process, it may be preferable that the surface of the hot-rolled steel sheet have a temperature of 720°C to 750°C owing to a heat recuperation phenomenon. Although the interior temperature of the hot-rolled steel sheet is adjusted to be within the range of 650°C to 750°C through the cooling process, the surface temperature of the hot-rolled steel sheet is lower than the range because of rapid cooling. Therefore, the hot-rolled steel sheet may be allowed to undergo heat recuperation so as to activate the movement of alloying elements effective in forming an oxide layer and thus to form a rich layer having a sufficient thickness. To sufficiently obtain these effects, the surface temperature of the hot-rolled steel sheet may preferably be 720°C or higher after heat recuperation. However, the surface temperature of the hot-rolled steel sheet will not exceed 750°C even if the heat recuperation is sufficient.
  • The coiled hot-rolled steel sheet is slowly cooled to a cooling finish temperature of 350°C to 400°C at a rate of 30°C/hr to 40°C/hr. If the slow cooling rate is excessively high, copper (Cu) forming a rich layer may not sufficiently move, and thus it may be difficult to form a rich layer having a sufficient thickness. Therefore, it may be preferable that the slow cooling rate be within the range of 40°C/hr or less. However, if the slow cooling rate is less than 30°C/hr, the size of grains may increase excessively, and thus, the strength of the hot-rolled steel sheet may decrease. Thus, the slow cooling rate may preferably be within the range of 30°C/hr to 40°C/hr. In addition, if the cooling finish temperature is lower than 350°C, properties of the hot-rolled steel sheet such as ductility may deteriorate, and productivity may decrease. Conversely, if the cooling finish temperature is higher than 400°C, a rich layer having a sufficient thickness may not be formed, and thus the hot-rolled steel sheet may have poor corrosion resistance. Therefore, the cooling finish temperature may preferably be within the range of 350°C to 400°C.
    • [Mode for Invention]
  • Hereinafter, the present disclosure will be described more specifically through examples. However, the following examples should be considered in a descriptive sense only, and are not for purposes of limitation. The scope of the present invention is defined by the appended claims, and modifications and variations may be reasonably made therefrom.
    • (Examples)
  • Steel ingots, manufactured through a melting process and having compositions as illustrated in Table 1 below, were maintained in a heating furnace for one hour at 1200°C and were subjected to a hot rolling process. In this case, finish hot rolling was performed at 900°C, and hot-rolled steel sheets having a thickness of 4.5 mm were ultimately manufactured. Thereafter, the hot-rolled steel sheets were cooled, coiled, and maintained under the conditions shown in Table 2 below. Thereafter, the hot-rolled steel sheets were slowly cooled to 380°C at a rate of 35°C/h, thereby completing the manufacturing of the hot-rolled steel sheets.
  • To observe corrosion characteristics of the hot-rolled steel sheets, specimens of the hot-rolled steel sheets were placed in a solution having a temperature of 60°C and containing 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid for 6 hours, and subsequently, the corrosion loss of each specimen was measured as shown in Table 2 below.
  • In addition, after the immersion in the sulfuric acid-hydrochloric acid composite corrosive environment, the thickness of an oxide layer (corrosion-resistant layer) of each hot-rolled steel sheet was measured as shown in Table 2. [Table 1]
    Steels Composition (wt%)
    C Mn P S Al Cu Sb
    Inventive Steel 1 0.075 0.69 0.012 0.009 0.033 0.32 0.08
    Inventive Steel 2 0.068 0.67 0.011 0.009 0.029 0.39 0.06
    Inventive Steel 3 0.074 0.75 0.009 0.01 0.029 0.44 0.05
    Comparative Steel 1 0.069 0.74 0.012 0.011 0.035 0.28 -
    [Table 2]
    Steels Cooling Rate Coiling Temperature Corrosion Loss Thickness of Oxide Examples
    (°C/s) (°C) (mg/cm2/hr) Layer (nm)
    Inventive Steel 1 130 700 1.8 420 Inventive Example 1
    130 500 4.5 57 Comparative Example 1
    10 700 3.8 63 Comparative Example 2
    Inventive Steel 2 130 700 1.6 440 Inventive Example 2
    10 700 3.6 69 Comparative Example 3
    Inventive Steel 3 130 700 1.4 460 Inventive Example 3
    10 700 3.2 75 Comparative Example 4
    Comparative Steel 1 130 700 8.8 220 Comparative Example 5
  • As shown in Tables 1 and 2, Inventive Examples 1 to 3 satisfying the alloying composition and manufacturing conditions proposed in the present disclosure had a corrosion loss of 2.0 mg/cm2/hr or less in the sulfuric acid-hydrochloric acid corrosive environment owing to the formation of oxide layers having a thickness of 400 nm or greater. That is, Inventive Examples 1 to 3 had high corrosion resistance.
  • Although Comparative Example 1 satisfied the alloying composition of the present disclosure, the coiling temperature of Comparative Example 1 was low, 500°C. Thus, an oxide layer was not sufficiently formed, resulting in corrosion loss of 4.5 mg/cm2/hr. That is, Comparative Example 1 had poor corrosion resistance.
  • Although Comparative Examples 2 to 4 satisfied the alloying composition of the present disclosure, the cooling rate of Comparative Example 2 to 4 was low, 10°C/s. Thus, oxide layers were not sufficiently formed, resulting in a corrosion loss of 3.2 mg/cm2/hr or greater. That is, Comparative Examples 2 to 4 had poor corrosion resistance.
  • Although Comparative Example 5 satisfied the manufacturing conditions of the present disclosure, antimony (Sb) was not added to Comparative Example 5, resulting in a corrosion loss of 8.8 mg/cm2/hr in the sulfuric acid-hydrochloric acid corrosive environment. That is, Comparative Example 5 had poor corrosion resistance. The reason for this is that a Cu-Sb composite oxide having high corrosion resistance was not formed in an oxide layer.
  • While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present invention as defined by the appended claims.

Claims (6)

  1. A hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid, the hot-rolled steel sheet comprising, by wt%, carbon (C): 0.05% to 0.1%, manganese (Mn): 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% or less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb): 0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities, wherein copper (Cu) and antimony (Sb) are concentrated in a region from a surface to a 500-nm position in a thickness direction of the hot-rolled steel sheet, and the hot-rolled steel sheet has a corrosion loss of 2.0 mg/cm2/hr in 6 hours or less in a solution of 16.9 volume% sulfuric acid and 0.35 volume% hydrochloric acid having a temperature of 60°C.
  2. The hot-rolled steel sheet of claim 1, wherein the inevitable impurities comprise tungsten (W), molybdenum (Mo), cobalt (Co), and nickel (Ni) in a total amount of less than 10 ppm.
  3. The hot-rolled steel sheet of claim 1, wherein the concentrated copper (Cu) and antimony (Sb) form an oxide layer comprising a Cu-Sb composite oxide in a corrosive environment containing sulfuric acid and hydrochloric acid.
  4. The hot-rolled steel sheet of claim 3, wherein the oxide layer has a thickness of 400 nm to 500 nm from the surface of the hot-rolled steel sheet in the thickness direction of the hot-rolled steel sheet.
  5. A method for manufacturing a hot-rolled steel sheet having high composite corrosion resistance to sulfuric acid and hydrochloric acid, the method comprising:
    reheating a steel slab to 1100°C to 1300°C, the steel slab comprising, by wt%, carbon (C): 0.05% to 0.1%, manganese (Mn): 0.5% to 1.5%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% or less, aluminum (Al): 0.01% to 0.1%, copper (Cu): 0.2% to 0.6%, antimony (Sb): 0.05% to 0.1%, and a balance of iron (Fe) and inevitable impurities;
    obtaining a hot-rolled steel sheet by hot rolling the reheated steel slab and finish hot rolling the steel slab at a temperature of 850°C to 950°C;
    rapidly cooling the hot-rolled steel sheet at a rate of 120°C/s to 150°C/s;
    coiling the cooled hot-rolled steel sheet at a temperature of 650°C to 750°C; and
    slowly cooling the coiled hot-rolled steel sheet at a rate of 30°C/hr to 40°C/hr to a cooling finish temperature of 350°C to 400°C.
  6. The method of claim 5, wherein during the coiling of the cooled hot-rolled steel sheet, a surface of the hot-rolled steel sheet reaches a temperature of 720°C to 750°C through a heat recuperation phenomenon.
EP15893419.0A 2015-05-28 2015-05-28 Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor Active EP3305936B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/KR2015/005381 WO2016190467A1 (en) 2015-05-28 2015-05-28 Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor

Publications (3)

Publication Number Publication Date
EP3305936A4 EP3305936A4 (en) 2018-04-11
EP3305936A1 EP3305936A1 (en) 2018-04-11
EP3305936B1 true EP3305936B1 (en) 2019-07-10

Family

ID=57393247

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15893419.0A Active EP3305936B1 (en) 2015-05-28 2015-05-28 Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor

Country Status (6)

Country Link
US (1) US20180148811A1 (en)
EP (1) EP3305936B1 (en)
JP (1) JP6549254B2 (en)
KR (1) KR102098511B1 (en)
CN (1) CN107614721B (en)
WO (1) WO2016190467A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110629124B (en) * 2018-06-25 2021-09-17 宝山钢铁股份有限公司 Rare-sulfuric-acid-corrosion-resistant microalloyed steel and heat treatment method of steel plate/steel pipe thereof
KR20200065990A (en) * 2018-11-30 2020-06-09 주식회사 포스코 Corrosion resistant steel having high resistance to corrosion at sulfuric and sulfuric/hydrochloric acid condensing environment and manufacturing method the same
WO2021095182A1 (en) * 2019-11-13 2021-05-20 日本製鉄株式会社 Steel material
KR20220063244A (en) * 2019-11-13 2022-05-17 닛폰세이테츠 가부시키가이샤 hot rolled steel
KR102326323B1 (en) * 2019-12-19 2021-11-12 주식회사 포스코 A steel sheet having high abrasion resistance and corrosion resistance at sulfuric/hydrochloric acid condensing environment and manufacturing method the same
KR102352601B1 (en) 2020-11-19 2022-01-18 주식회사 포스코 Shielded metal arc welding material
KR102468054B1 (en) 2020-11-19 2022-11-17 주식회사 포스코 Welded joint having excellent wear resistance and corrosion resistance
CN115161547A (en) * 2022-04-27 2022-10-11 日照钢铁控股集团有限公司 Manufacturing method of atmospheric corrosion resistant checkered plate

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3459538A (en) * 1965-03-25 1969-08-05 Fuji Iron & Steel Co Ltd Corrosion resistant low-alloy steel
US3443934A (en) * 1965-04-12 1969-05-13 Nippon Kokan Kk Steel alloys resistant to sulfuric acid and containing small quantity of alloying elements of copper,chromium,and tin or antimony
JPS5696053A (en) * 1979-12-29 1981-08-03 Nippon Steel Corp Steel with hydrogen sulfide crack resistance
US5045279A (en) * 1989-06-01 1991-09-03 Queiroz Pinto Jose A De Corrosion-resistant carbon steel with good drawability characteristics
JPH0925536A (en) * 1995-07-06 1997-01-28 Sumitomo Metal Ind Ltd Acid dew point corrosion resistant steel
JP3584636B2 (en) * 1996-10-08 2004-11-04 住友金属工業株式会社 Sulfuric acid / hydrochloric acid dew-point corrosion resistant steel with excellent hot workability
JP3699669B2 (en) 2001-10-01 2005-09-28 新日本製鐵株式会社 Steel with excellent resistance to molten acid ammonium sulfate corrosion
JP4319817B2 (en) * 2001-11-19 2009-08-26 新日本製鐵株式会社 Low alloy steel excellent in hydrochloric acid corrosion resistance and sulfuric acid corrosion resistance and its welded joint
JP4997808B2 (en) * 2006-03-30 2012-08-08 Ｊｆｅスチール株式会社 Sulfuric acid dew-point corrosion steel with excellent hydrochloric acid resistance
JP5365187B2 (en) * 2008-12-26 2013-12-11 Ｊｆｅスチール株式会社 Method for producing marine structural steel with excellent corrosion resistance
CN102575327A (en) * 2009-09-30 2012-07-11 杰富意钢铁株式会社 Steel material for structures having excellent weather resistance and steel structure
JP5862323B2 (en) * 2011-01-31 2016-02-16 Ｊｆｅスチール株式会社 Corrosion resistant steel for holding coal ships or coal / ore combined ships
JP5686632B2 (en) 2011-02-28 2015-03-18 日新製鋼株式会社 Sulfuric acid dew point corrosion steel and exhaust gas flow path components
KR101417294B1 (en) * 2012-06-21 2014-07-08 주식회사 포스코 Hot-rolled steel sheet having excellent multi-corrosion resistant and weldability and method for manufacturing thereof
KR101500048B1 (en) * 2012-12-27 2015-03-06 주식회사 포스코 Method for manufacturing steel sheet having superior resistance to corrosion by sulfuric acid
KR101518578B1 (en) * 2013-09-10 2015-05-07 주식회사 포스코 Steel for complex corrosion resistance to hydrochloric acid and sulfuric acid having excellent wear resistance and surface qualities and method for manufacturing the same
KR101560902B1 (en) * 2013-12-06 2015-10-15 주식회사 포스코 Hot rolled steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and method for manufacturing the same
CN104451457A (en) * 2014-11-20 2015-03-25 南京钢铁股份有限公司 Hot rolled steel strip with resistance to corrosion of hydrochloric acid and sulfuric acid and production method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
CN107614721B (en) 2019-08-13
EP3305936A4 (en) 2018-04-11
KR20180027534A (en) 2018-03-14
WO2016190467A1 (en) 2016-12-01
JP2018519422A (en) 2018-07-19
US20180148811A1 (en) 2018-05-31
KR102098511B1 (en) 2020-04-07
EP3305936A1 (en) 2018-04-11
CN107614721A (en) 2018-01-19
JP6549254B2 (en) 2019-07-24

Similar Documents

Publication Publication Date Title
EP3305936B1 (en) Hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid and manufacturing method therefor
JP5885884B2 (en) Ferritic stainless hot-rolled steel sheet, manufacturing method thereof, and steel strip
KR101560902B1 (en) Hot rolled steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and method for manufacturing the same
KR101417295B1 (en) Cold-rolled steel sheet having excellent sulfuric acid-corrosion resistant and surface properties and method for manufacturing thereof
JP6817434B2 (en) Steel materials for pressure vessels with excellent hydrogen-induced cracking resistance and their manufacturing methods
KR101372794B1 (en) Steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and weldability and method for manufacturing the same
KR101536438B1 (en) Steel sheet for complex corrosion resistance to sulfuric acid and hydrochloric acid and method for manufacturing the same
KR101417294B1 (en) Hot-rolled steel sheet having excellent multi-corrosion resistant and weldability and method for manufacturing thereof
KR101493853B1 (en) Hot-rolled steel sheet and manufacturing method thereof
EP3044344B1 (en) Steel for resistance to complex corrosion from hydrochloric acid and sulfuric acid, having excellent wear resistance and surface qualities, and method of manufacturing the same
JP5462742B2 (en) Method for producing high-strength steel sheet with excellent mechanical property stability
CN109440017A (en) The excellent high-intensitive low-gravity steel plate of spot weldability
KR101304708B1 (en) High ductility hot-rolled steel sheet having excellent corrosion resistance and method for manufacturing the same
CN111479944A (en) Ferrite-based stainless steel having excellent impact toughness and method for producing the same
KR101536429B1 (en) Steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and method for manufacturing the same
KR101543874B1 (en) Hot rolled steel for complex corrosion resistance to hydrochloric acid and sulfuric acid, having excellent corrosion resistance, and method of manufacturing the same
KR101304637B1 (en) High strength and high ductility hot-rolled steel sheet having excellent corrosion resistance and method for manufacturing the same
KR101242807B1 (en) Low alloy hot-rolled steel sheet having excellent corrosion resistance and method for manufacturing the same
JP3879365B2 (en) Manufacturing method of steel material with excellent fatigue crack growth resistance
KR101243011B1 (en) High strength low alloy hot-rolled steel sheet having excellent corrosion resistance and method for manufacturing the same
KR102368362B1 (en) A steel sheet having high abrasion resistance and corrosion resistance at sulfuric/hydrochloric acid condensing environment and manufacturing method the same
JP2024098487A (en) Steel
JP3975674B2 (en) Low alloy steel manufacturing method

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20171221

A4 Supplementary search report drawn up and despatched

Effective date: 20180305

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: C22C 38/60 20060101ALI20181128BHEP

Ipc: C22C 38/16 20060101AFI20181128BHEP

Ipc: C22C 38/06 20060101ALI20181128BHEP

Ipc: C22C 38/00 20060101ALI20181128BHEP

Ipc: C21D 8/02 20060101ALI20181128BHEP

Ipc: C21D 9/46 20060101ALI20181128BHEP

Ipc: C22C 38/04 20060101ALI20181128BHEP

Ipc: C21D 6/00 20060101ALI20181128BHEP

INTG Intention to grant announced

Effective date: 20181221

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: AT

Ref legal event code: REF

Ref document number: 1153652

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190715

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602015033775

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20190710

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1153652

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191111

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191010

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191010

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191110

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191011

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200224

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602015033775

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG2D Information on lapse in contracting state deleted

Ref country code: IS

26N No opposition filed

Effective date: 20200603

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200531

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200531

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20200531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200528

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200528

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190710

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602015033775

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG-SI, KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602015033775

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG- SI, KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602015033775

Country of ref document: DE

Owner name: POSCO HOLDINGS INC., KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20221027 AND 20221102

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602015033775

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG-SI, KR

Free format text: FORMER OWNER: POSCO HOLDINGS INC., SEOUL, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602015033775

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG- SI, KR

Free format text: FORMER OWNER: POSCO HOLDINGS INC., SEOUL, KR

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20230522

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20240422

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20240422

Year of fee payment: 10