WO2023063678A1 - 절삭성능이 우수한 유황 첨가 흑연강 선재, 강선, 흑연강 및 그 제조방법 - Google Patents
절삭성능이 우수한 유황 첨가 흑연강 선재, 강선, 흑연강 및 그 제조방법 Download PDFInfo
- Publication number
- WO2023063678A1 WO2023063678A1 PCT/KR2022/015274 KR2022015274W WO2023063678A1 WO 2023063678 A1 WO2023063678 A1 WO 2023063678A1 KR 2022015274 W KR2022015274 W KR 2022015274W WO 2023063678 A1 WO2023063678 A1 WO 2023063678A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- graphite
- wire rod
- steel
- steel wire
- cutting performance
- Prior art date
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 129
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 97
- 239000010439 graphite Substances 0.000 title claims abstract description 97
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 88
- 239000010959 steel Substances 0.000 title claims abstract description 88
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 45
- 238000005520 cutting process Methods 0.000 title claims abstract description 37
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000011572 manganese Substances 0.000 claims abstract description 44
- 239000010936 titanium Substances 0.000 claims abstract description 44
- 238000005087 graphitization Methods 0.000 claims abstract description 38
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 34
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 33
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000011593 sulfur Substances 0.000 claims abstract description 32
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910052796 boron Inorganic materials 0.000 claims abstract description 28
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 26
- 239000010703 silicon Substances 0.000 claims abstract description 26
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 25
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 25
- 229910001562 pearlite Inorganic materials 0.000 claims abstract description 25
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 25
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 24
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 24
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000012535 impurity Substances 0.000 claims abstract description 22
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 22
- 239000011574 phosphorus Substances 0.000 claims abstract description 22
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 10
- 239000011159 matrix material Substances 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims description 38
- 238000001816 cooling Methods 0.000 claims description 26
- 238000005098 hot rolling Methods 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 10
- 229910000915 Free machining steel Inorganic materials 0.000 abstract description 20
- 230000000052 comparative effect Effects 0.000 description 28
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 12
- 230000000694 effects Effects 0.000 description 11
- 238000005096 rolling process Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 6
- 229910001566 austenite Inorganic materials 0.000 description 5
- 230000009931 harmful effect Effects 0.000 description 5
- 150000004767 nitrides Chemical class 0.000 description 5
- 229910052718 tin Inorganic materials 0.000 description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910001567 cementite Inorganic materials 0.000 description 4
- 238000005261 decarburization Methods 0.000 description 4
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000009828 non-uniform distribution Methods 0.000 description 4
- 239000006104 solid solution Substances 0.000 description 4
- 229910052797 bismuth Inorganic materials 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- -1 microstructure Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 230000010152 pollination Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 230000003313 weakening effect Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005194 fractionation Methods 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000010451 perlite Substances 0.000 description 1
- 235000019362 perlite Nutrition 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Classifications
-
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C23/00—Extruding metal; Impact extrusion
- B21C23/02—Making uncoated products
- B21C23/04—Making uncoated products by direct extrusion
- B21C23/08—Making wire, bars, tubes
-
- 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
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
-
- 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
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
-
- 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
-
- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
Definitions
- the present invention relates to a graphite steel wire rod, steel wire, graphite steel having excellent cutting performance, and a manufacturing method thereof, and more particularly, to a sulfur-added graphite steel wire rod, steel wire, graphite steel having better cutting performance than general free-cutting steel, and manufacturing thereof It's about how.
- free-cutting steel to which machinability imparting elements such as Pb, Bi, and S are added is used as a material for machine parts or the like requiring machinability.
- machinability imparting elements such as Pb, Bi, and S
- liquid metal embrittlement is used by adding low melting point machinability imparting elements such as Pb and Bi to steel, or a large amount of MnS is formed in steel.
- the machinability of steel such as chip control and tool life is excellent.
- Graphite steel is a free-cutting steel developed to solve the above problems.
- Graphite steel is a steel containing fine graphite grains inside a ferrite matrix or a ferrite and pearlite matrix, and the fine graphite grains inside act as a crack source during cutting This steel has good machinability by playing the role of a chip breaker.
- graphite steel is currently not commercialized. This is because when carbon is added to steel, graphite is precipitated as metastable cementite, even though it is a stable phase, and it is difficult to precipitate graphite without a separate long heat treatment of 10 hours or more, and decarburization occurs during such a long heat treatment process. This is because harmful effects that adversely affect the performance of the final product occur.
- the present invention is to provide a sulfur-added graphite steel wire having excellent cutting properties, a steel wire, graphite steel, and a manufacturing method thereof.
- the graphite steel according to the present invention has excellent cutting performance, so it can replace existing free-cutting steel materials, and can be used as an eco-friendly free-cutting steel that replaces harmful elements such as Pb.
- Carbon is an essential element for forming graphite grains.
- the carbon content is less than 0.60% by weight, the effect of improving the machinability is insufficient, and the distribution of graphite grains is uneven even when graphitization is completed. There is a possibility that the machinability, in particular, the surface roughness may decrease. Therefore, the upper limit of the carbon content is preferably 0.90% by weight.
- Silicon is a necessary component as a deoxidizer in the manufacture of molten steel and is positively added because it is a graphitization promoting element that destabilizes cementite in steel so that carbon can be precipitated as graphite.
- the content of silicon is preferably 2.0% by weight or more.
- the upper limit of the silicon content is preferably 2.5% by weight.
- Manganese improves strength and impact properties of steel, and contributes to improving machinability by forming MnS inclusions in combination with sulfur in steel.
- manganese is preferably included in an amount of 0.1% by weight or more.
- the upper limit of the manganese content is preferably 0.6% by weight.
- Phosphorus is an unavoidable impurity. Although phosphorus helps machinability by weakening the grain boundaries of steel, it increases the hardness of ferrite by a significant solid solution hardening effect, reduces the toughness and resistance to delayed fracture of steel, and promotes the occurrence of surface defects. It is desirable to manage as low as possible. Theoretically, it is advantageous to control the phosphorus content to 0% by weight, but it is inevitably contained in the manufacturing process. Therefore, it is important to manage the upper limit, and in the present invention, the upper limit is managed at 0.015% by weight.
- Sulfur has an effect of improving machinability by generating MnS, but when it is excessively included, mechanical anisotropy appears due to MnS elongated by rolling.
- the generation of MnS was induced by adding sulfur within a range that can contribute to improving machinability without causing mechanical anisotropy.
- sulfur is included in the range of 0.031 to 0.3% by weight, MnS is generated to improve cutability, and 100% cutting performance is shown compared to leaded free-cutting steel.
- the sulfur content is controlled to less than 0.031% by weight, the fraction of MnS inclusions that can improve cutting performance cannot be made.
- the anisotropy of the material increases, resulting in a phenomenon of breakage during cutting, resulting in a risk during processing.
- Aluminum is an element that promotes graphitization next to silicon. This is because aluminum destabilizes cementite when present as solid solution Al, so it is necessary to exist as solid solution Al. In the present invention, in order to exhibit such an effect, it is preferably included in an amount of 0.01% by weight or more. On the other hand, if the content is excessive, the effect is not only saturated, but also can cause nozzle clogging during playing, and AlN is generated at the austenite grain boundary, and graphite with it as a nucleus is non-uniformly distributed at the grain boundary. Therefore, the upper limit of the aluminum content is preferably 0.05% by weight.
- Titanium combines with nitrogen such as boron and aluminum to produce nitrides such as TiN, BN, and AlN, and these nitrides act as nuclei for graphite generation during constant temperature heat treatment.
- TiN has a higher formation temperature than AlN or BN and crystallizes before austenite is completed, so uniform distribution in austenite grain boundaries and grains. will do Therefore, graphite grains generated by using TiN as a nucleation site are also finely and uniformly distributed.
- Nitrogen is combined with titanium, boron, and aluminum to form TiN, BN, AlN, etc.
- nitrides such as BN and AlN are mainly formed at austenite grain boundaries.
- graphite since graphite is formed with these nitrides as nuclei, it may cause non-uniform distribution of graphite, so an appropriate amount of addition is required. If the amount of nitrogen added is excessive, it cannot be combined with the nitride-forming element, and if it exists in steel as solid nitrogen, it has a disadvantageous effect of increasing strength and stabilizing cementite to delay graphitization.
- the content of nitrogen is limited to 0.0030% by weight as the lower limit and 0.0150% by weight as the upper limit for the reason that it is consumed to form nitride that acts as a graphite nucleation site and does not remain as solid nitrogen.
- BN acts as a nucleus for crystallization of graphite and promotes graphitization, so it is actively added. Since it is excessively generated at the grain boundary and causes non-uniform distribution of graphite grains after graphitization heat treatment, as well as weakening the grain boundary and causing a problem of remarkably deteriorating hot rolling properties, it is preferable to contain it in the range of 0.0005 to 0.0020% by weight. .
- the remaining components of the present invention are iron (Fe) and unavoidable impurities.
- Fe iron
- unavoidable impurities since unintended impurities from raw materials or the surrounding environment may inevitably be mixed in the normal steel manufacturing process, this cannot be excluded. Since these impurities are known to anyone skilled in the ordinary steel manufacturing process, not all of them are specifically mentioned in this specification.
- the wire rod for graphitization heat treatment may have an area fraction of pearlite of 95% or more.
- the graphite grains are produced by decomposition of pearlite, when the area fraction of pearlite is low, the fraction of graphite grains is inevitably low, and non-uniform distribution is shown, which is undesirable. Since it is advantageous to secure uniform and fine graphite grains when the area fraction of pearlite is high, the upper limit is not particularly limited.
- a step of cooling the wire rod is included.
- the heating step may include heat treatment by maintaining for 60 minutes or more in the range of 1050 ⁇ 100 ° C.
- the heating temperature of the billet is less than 950 ° C.
- the load during rolling may increase and the rolling productivity may decrease, so there is a disadvantage at a low heating temperature.
- the heating temperature exceeds 1150 ° C., not only costs increase, but also decarburization is accelerated and the decarburization layer becomes thick, which is not preferable because it remains in the final product.
- the reason why the heating holding time is 60 minutes or more is that it is difficult to secure a uniform temperature distribution of the outside and inside of the billet for wire rod rolling when it is less than 60 minutes.
- the step of manufacturing a wire rod by hot rolling may include hot rolling in a temperature range of 900 to 1150 ° C.
- the wire rolling temperature is in the range of 900 to 1150°C, surface defects may easily occur during hot rolling if the temperature is lower than 900°C, or rolling may be difficult due to an increase in the rolling load. This is because the graphitization heat treatment time after wire rod rolling may increase due to coarsening.
- the cooling may include cooling to 500 °C at a cooling rate of 0.1 to 10.0 °C/s.
- the step of air cooling may be included after the step of cooling.
- cooling rate exceeds 10.0 °C or more, hard phases such as martensite are generated, which is undesirable because disconnection may occur during cold drawing, which is the process following wire rod rolling. This is undesirable because the graphite grains produced after the graphitization heat treatment may have non-uniform distribution due to reduced or coarsened crystal grain size.
- Graphite steel wire in weight%, carbon (C): 0.60 ⁇ 0.90%, silicon (Si): 2.0 ⁇ 2.5%, manganese (Mn): 0.1 ⁇ 0.6%, phosphorus (P): 0.015% or less (excluding 0), sulfur (S): 0.031 to 0.3%, aluminum (Al): 0.01 to 0.05%, titanium (Ti): 0.005 to 0.02%, boron (B): 0.0005 to 0.0020%, nitrogen (N): 0.0030 to 0.0150%, including the remainder Fe and unavoidable impurities.
- Graphite steel in weight%, carbon (C): 0.60 ⁇ 0.90%, silicon (Si): 2.0 ⁇ 2.5%, manganese (Mn): 0.1 ⁇ 0.6%, phosphorus (P): 0.015% or less (excluding 0), sulfur (S): 0.031 to 0.3%, aluminum (Al): 0.01 to 0.05%, titanium (Ti): 0.005 to 0.02%, boron (B): 0.0005 to 0.0020%, nitrogen (N): 0.0030 to 0.0150%, contains the remaining Fe and unavoidable impurities, has a microstructure, graphite grains are distributed in the ferrite matrix, the graphitization rate is 95% or more, and a total of 5% or less MnS inclusions and pearlite include
- the graphitization rate means the ratio of the carbon content present in the graphite state to the carbon content added to the steel, and is defined by the following [Relationship 1], and graphitization of 95% or more means that the added carbon is mostly graphite.
- graphitization of 95% or more means that the added carbon is mostly graphite.
- the graphitization heat treatment may include heat treatment for 5 hours or more at a temperature range of 700 to 800 ° C.
- a billet containing the components shown in Table 1 was maintained at a heating temperature for 90 minutes and then rolled at high speed to produce a wire rod having a diameter of 19 mm.
- the wire rod cooling rate, the area fraction of the wire rod pearlite, the graphitization heat treatment time, and the graphitization fraction are shown in Table 1 below.
- Examples 1 to 11 correspond to graphite steel wires satisfying the alloy composition range and manufacturing conditions of the present invention, and Comparative Examples 1 to 7 satisfy the alloy composition range and/or manufacturing conditions of the present invention. It corresponds to the good that does not.
- Example 1 0.65 2.1 0.25 0.14 0.015 0.0006 0.005 0.015 0.005 100
- Example 2 0.87 2.15 0.36 0.24 0.017 0.0015 0.008 0.023 0.008 100
- Example 3 0.72 2.35 0.47 0.035 0.007 0.0008 0.006 0.043 0.010 100
- Example 4 0.68 2.18 0.16 0.26 0.009 0.0009 0.009 0.035 0.009 100
- Example 5 0.82 2.25 0.55 0.05 0.012 0.0012 0.012 0.040 0.014 100
- Example 6 0.62 2.48 0.50 0.09 0.006 0.0018 0.014 0.042 0.012 100
- Example 7 0.73 2.42 0.2 0.16 0.011 0.0007 0.009 0.034 0.006 100
- Example 8 0.78 2.32 0.32 0.19 0.016 0.0017 0.008 0.019 0.008 100
- Example 9 0.85 2.15 0.48 0.27 0.009 0.0011 0.004 0.027 0.013 100
- Cutting performance is a figure based on the cutting performance of leaded free cutting steel (100% means equivalent level).
- the structure of (100% - graphitization fraction) consists of MnS inclusions and pearlite, and the graphitization structure consists of ferrite + graphite grains. It can be confirmed that the area fraction and graphitization fraction of pearlite are achieved under the wire rod and graphitization manufacturing conditions as shown in Table 2 above.
- Examples 1 to 11 satisfy the alloy composition range and manufacturing conditions of the present invention, so that the area fraction of pearlite of the graphite steel wire is 95% or more, the graphitization rate is 98.5% or more, and the cutting performance compared to leaded free cutting steel is 100% could confirm that
- the cutting performance of the graphite steel of Comparative Example 1 which had a sulfur content of only 0.005% by weight and substantially no boron, was only 88% of that of the leaded free-cutting steel, and the wire rod manufacturing method of Comparative Example 1 was 0.05 ° C / s By cooling at a cooling rate of , a wire rod having an area fraction of pearlite of 93% was obtained, and the heat treatment was maintained for 1.5 hours, resulting in a graphite content of only 75%.
- the cutting performance of the graphite steel of Comparative Example 2 in which the sulfur content was only 0.003% by weight and the boron content was only 0.0002% by weight, was only 95% compared to the leaded free-cutting steel, and the wire rod manufacturing method of Comparative Example 2 was 12.0 ° C. It was cooled at a cooling rate of /s to obtain a wire rod having an area fraction of pearlite of 93.5%, and the graphite content was only 85% as the heat treatment was maintained for 2.5 hours.
- the cutting performance of the graphite steel of Comparative Example 3 in which the sulfur content was only 0.006% by weight and the boron content was only 0.0004% by weight, was only 89% compared to the leaded free-cutting steel, and the wire rod manufacturing method of Comparative Example 3 was 11.5 ° C. It was cooled at a cooling rate of /s to obtain a wire rod having an area fraction of pearlite of 94.2%, and the graphite content was only 86% as the heat treatment was maintained for 3.0 hours.
- the cutting performance of the graphite steel of Comparative Example 4 having a carbon content of 0.95% by weight, a sulfur content of 0.007% by weight, and a boron content of 0.0025% by weight was only 92% compared to leaded free cutting steel.
- the wire rod manufacturing method was cooled at a cooling rate of 0.07° C./s to obtain a wire rod having an area fraction of pearlite of 93.2%, and the graphite content was only 85% as the heat treatment was maintained for 2.5 hours.
- the cutting performance of the graphite steel of Comparative Example 5 having a carbon content of 0.55% by weight, a silicon content of 2.6% by weight, a sulfur content of 0.4% by weight, a titanium content of 0.025% by weight, and a boron content of 0.0025% by weight was only 91% compared to leaded free-cutting steel, and the wire rod manufacturing method of Comparative Example 5 was cooled at a cooling rate of 15.5 ° C/s to obtain a wire rod having an area fraction of pearlite of 93.5%, and the heat treatment was maintained for 3.4 hours to obtain graphite The pollination rate was only 86%.
- the cutting performance of the graphite steel of Comparative Example 6 having a silicon content of 2.75% by weight, a manganese content of 0.9% by weight, a sulfur content of 0.45% by weight, a titanium content of 0.03% by weight, and a boron content of 0.0024% by weight was only 93% compared to leaded free-cutting steel, and the wire rod manufacturing method of Comparative Example 6 was cooled at a cooling rate of 14.0 ° C / s to obtain a wire rod having an area fraction of pearlite of 94.1%, and the heat treatment was maintained for 4.2 hours to obtain graphite The pollination rate was only 84%.
- the graphite steel of Comparative Example 7 having a silicon content of 2.8% by weight, a manganese content of 0.8% by weight, a sulfur content of 0.35% by weight, a titanium content of 0.002% by weight, and a boron content of 0.003% by weight was cut.
- the performance was only 90% of lead free cutting steel.
- the graphite steel according to the present invention has excellent cutting performance, it can replace existing free-cutting steel materials, and can be used as an eco-friendly free-cutting steel that replaces harmful elements such as Pb, so its industrial applicability is recognized.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Manufacturing & Machinery (AREA)
Abstract
Description
C | Si | Mn | S | Ti | B | P | Al | N | 절삭성능(%) | |
실시예 1 | 0.65 | 2.1 | 0.25 | 0.14 | 0.015 | 0.0006 | 0.005 | 0.015 | 0.005 | 100 |
실시예 2 | 0.87 | 2.15 | 0.36 | 0.24 | 0.017 | 0.0015 | 0.008 | 0.023 | 0.008 | 100 |
실시예 3 | 0.72 | 2.35 | 0.47 | 0.035 | 0.007 | 0.0008 | 0.006 | 0.043 | 0.010 | 100 |
실시예 4 | 0.68 | 2.18 | 0.16 | 0.26 | 0.009 | 0.0009 | 0.009 | 0.035 | 0.009 | 100 |
실시예 5 | 0.82 | 2.25 | 0.55 | 0.05 | 0.012 | 0.0012 | 0.012 | 0.040 | 0.014 | 100 |
실시예 6 | 0.62 | 2.48 | 0.50 | 0.09 | 0.006 | 0.0018 | 0.014 | 0.042 | 0.012 | 100 |
실시예 7 | 0.73 | 2.42 | 0.2 | 0.16 | 0.011 | 0.0007 | 0.009 | 0.034 | 0.006 | 100 |
실시예 8 | 0.78 | 2.32 | 0.32 | 0.19 | 0.016 | 0.0017 | 0.008 | 0.019 | 0.008 | 100 |
실시예 9 | 0.85 | 2.15 | 0.48 | 0.27 | 0.009 | 0.0011 | 0.004 | 0.027 | 0.013 | 100 |
실시예 10 | 0.75 | 2.26 | 0.14 | 0.21 | 0.018 | 0.001 | 0.010 | 0.030 | 0.007 | 100 |
실시예 11 | 0.73 | 2.46 | 0.41 | 0.15 | 0.008 | 0.0015 | 0.012 | 0.020 | 0.008 | 100 |
비교예 1 | 0.63 | 2.0 | 0.23 | 0.005 | 0.016 | 0.000 | 0.017 | 0.005 | 0.001 | 88 |
비교예 2 | 0.68 | 2.2 | 0.35 | 0.003 | 0.02 | 0.0002 | 0.020 | 0.006 | 0.002 | 95 |
비교예 3 | 0.73 | 2.25 | 0.45 | 0.006 | 0.009 | 0.0004 | 0.025 | 0.075 | 0.018 | 89 |
비교예 4 | 0.95 | 2.15 | 0.3 | 0.007 | 0.018 | 0.0025 | 0.023 | 0.060 | 0.020 | 92 |
비교예 5 | 0.55 | 2.6 | 0.56 | 0.4 | 0.025 | 0.0025 | 0.019 | 0.003 | 0.025 | 91 |
비교예 6 | 0.8 | 2.75 | 0.9 | 0.45 | 0.03 | 0.0024 | 0.018 | 0.065 | 0.021 | 93 |
비교예 7 | 0.75 | 2.8 | 0.8 | 0.35 | 0.002 | 0.003 | 0.020 | 0.06 | 0.022 | 90 |
구분 | 선재 | 흑연화 | |||
냉각개시온도 (oC) |
냉각속도 (℃ |
펄라이트의 면적분율 (%) |
유지시간 (hr) |
흑연화분율 (%) |
|
실시예 1 | 880 | 0.5 | 95.1 | 6.5 | 99 |
실시예 2 | 865 | 7.5 | 96.5 | 8.1 | 99 |
실시예 3 | 815 | 1.5 | 95.1 | 7.5 | 100 |
실시예 4 | 795 | 3.2 | 96.0 | 5.5 | 100 |
실시예 5 | 865 | 5.0 | 97.5 | 9.4 | 100 |
실시예 6 | 850 | 2.0 | 95.5 | 5.6 | 99.5 |
실시예 7 | 795 | 9.0 | 96.5 | 6.4 | 100 |
실시예 8 | 755 | 4.5 | 96.0 | 7.2 | 98.5 |
실시예 9 | 890 | 6.0 | 96.5 | 8.5 | 100 |
비교예 1 | 915 | 0.05 | 93.0 | 1.5 | 75 |
비교예 2 | 865 | 12.0 | 93.5 | 2.5 | 85 |
비교예 3 | 815 | 11.5 | 94.2 | 3.0 | 86 |
비교예 4 | 740 | 0.07 | 93.2 | 2.5 | 85 |
비교예 5 | 880 | 15.5 | 93.5 | 3.4 | 86 |
비교예 6 | 830 | 14.0 | 94.1 | 4.2 | 84 |
Claims (11)
- 중량%로 탄소(C): 0.60~0.90%, 실리콘(Si): 2.0~2.5%, 망간(Mn): 0.1~0.6%, 인(P): 0.015% 이하(0을 제외), 유황(S): 0.031~0.3%, 알루미늄(Al): 0.01~0.05%, 타이타늄(Ti): 0.005~0.02%, 보론(B): 0.0005~0.0020%, 질소(N): 0.0030~0.0150%, 나머지 Fe 및 불가피한 불순물을 포함하는, 절삭성능이 우수한 흑연강 선재.
- 청구항 1에 있어서,펄라이트의 면적분율이 95% 이상인, 절삭성능이 우수한 흑연강 선재.
- 중량%로 탄소(C): 0.60~0.90%, 실리콘(Si): 2.0~2.5%, 망간(Mn): 0.1~0.6%, 인(P): 0.015% 이하(0을 제외), 유황(S): 0.031~0.3%, 알루미늄(Al): 0.01~0.05%, 타이타늄(Ti): 0.005~0.02%, 보론(B): 0.0005~0.0020%, 질소(N): 0.0030~0.0150%, 나머지 Fe 및 불가피한 불순물을 포함하는 빌렛을 제조하는 단계;상기 빌렛을 가열하는 단계;상기 가열된 빌렛을 열간 압연하여 선재로 제조하는 단계; 및상기 선재를 냉각하는 단계를 포함하는, 절삭성능이 우수한 흑연강 선재의 제조방법.
- 청구항 3에 있어서, 상기 가열하는 단계는, 1050±100℃범위에서 60분 이상 유지하여 열처리하는 것을 포함하는, 절삭성능이 우수한 흑연강 선재의 제조방법.
- 청구항 3에 있어서, 상기 열간 압연하여 선재로 제조하는 단계는, 900~1150℃의 온도범위에서 열간 압연하는 것을 포함하는, 절삭성능이 우수한 흑연강 선재의 제조방법.
- 청구항 3에 있어서, 상기 냉각하는 단계는, 0.1~10.0℃/s의 냉각속도로 500℃까지 냉각하는 것을 포함하는, 절삭성능이 우수한 흑연강 선재의 제조방법.
- 청구항 3에 있어서, 상기 냉각하는 단계 이후에, 공냉하는 단계를 더 포함하는, 절삭성능이 우수한 흑연강 선재의 제조방법.
- 중량%로 탄소(C): 0.60~0.90%, 실리콘(Si): 2.0~2.5%, 망간(Mn): 0.1~0.6%, 인(P): 0.015% 이하(0을 제외), 유황(S): 0.031~0.3%, 알루미늄(Al): 0.01~0.05%, 타이타늄(Ti): 0.005~0.02%, 보론(B): 0.0005~0.0020%, 질소(N): 0.0030~0.0150%, 나머지 Fe 및 불가피한 불순물을 포함하는, 절삭성능이 우수한 흑연강 강선.
- 중량%로 탄소(C): 0.60~0.90%, 실리콘(Si): 2.0~2.5%, 망간(Mn): 0.1~0.6%, 인(P): 0.015% 이하(0을 제외), 유황(S): 0.031~0.3%, 알루미늄(Al): 0.01~0.05%, 타이타늄(Ti): 0.005~0.02%, 보론(B): 0.0005~0.0020%, 질소(N): 0.0030~0.0150%, 나머지 Fe 및 불가피한 불순물을 포함하고,미세조직으로, 페라이트 기지에 흑연립이 분포되어 있으며, 흑연화율이 95% 이상이며, 총 5% 이하의 MnS 개재물과 펄라이트를 포함하는, 절삭성능이 우수한 흑연강.
- 중량%로 탄소(C): 0.60~0.90%, 실리콘(Si): 2.0~2.5%, 망간(Mn): 0.1~0.6%, 인(P): 0.015% 이하(0을 제외), 유황(S): 0.031~0.3%, 알루미늄(Al): 0.01~0.05%, 타이타늄(Ti): 0.005~0.02%, 보론(B): 0.0005~0.0020%, 질소(N): 0.0030~0.0150%, 나머지 Fe 및 불가피한 불순물을 포함하는 선재를 제조하는 단계; 및상기 제조된 선재를 흑연화 열처리하는 단계를 포함하는, 절삭성능이 우수한 흑연강의 제조방법.
- 청구항 10에 있어서,상기 흑연화 열처리하는 단계는, 700~800℃의 온도범위에서 5시간 이상 열처리하는 것을 포함하는, 절삭성능이 우수한 흑연강의 제조방법.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP22881305.1A EP4394072A1 (en) | 2021-10-12 | 2022-10-11 | Sulfur-added graphite steel wire rod, steel wire and graphite steel, which have excellent cutting performance, and manufacturing methods therefor |
CN202280068336.4A CN118076760A (zh) | 2021-10-12 | 2022-10-11 | 具有优异切削性能的添加有硫的石墨钢线材、钢丝和石墨钢及其制造方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020210135091A KR20230052013A (ko) | 2021-10-12 | 2021-10-12 | 절삭성능이 우수한 유황 첨가 흑연강 선재, 강선, 흑연강 및 그 제조방법 |
KR10-2021-0135091 | 2021-10-12 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023063678A1 true WO2023063678A1 (ko) | 2023-04-20 |
Family
ID=85988461
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/KR2022/015274 WO2023063678A1 (ko) | 2021-10-12 | 2022-10-11 | 절삭성능이 우수한 유황 첨가 흑연강 선재, 강선, 흑연강 및 그 제조방법 |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP4394072A1 (ko) |
KR (1) | KR20230052013A (ko) |
CN (1) | CN118076760A (ko) |
WO (1) | WO2023063678A1 (ko) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11131187A (ja) * | 1997-10-24 | 1999-05-18 | Kobe Steel Ltd | 迅速黒鉛化鋼および迅速黒鉛化鋼の製造方法 |
JPH11350066A (ja) * | 1998-06-04 | 1999-12-21 | Nkk Joko Kk | 被削性に優れた熱間鍛造鋼部品の製造方法及びその部品並びにそれに用いる熱間圧延鋼材 |
KR100349008B1 (ko) * | 1998-03-04 | 2002-08-17 | 신닛뽄세이테쯔 카부시키카이샤 | 냉간 단조용 강 및 그 제조방법 |
EP2530177A1 (en) * | 2010-01-25 | 2012-12-05 | Nippon Steel Corporation | Steel plate for cold forging and process for producing same |
KR102224044B1 (ko) * | 2018-12-18 | 2021-03-09 | 주식회사 포스코 | 흑연화 열처리용 선재와 흑연강 및 그 제조방법 |
-
2021
- 2021-10-12 KR KR1020210135091A patent/KR20230052013A/ko unknown
-
2022
- 2022-10-11 CN CN202280068336.4A patent/CN118076760A/zh active Pending
- 2022-10-11 EP EP22881305.1A patent/EP4394072A1/en active Pending
- 2022-10-11 WO PCT/KR2022/015274 patent/WO2023063678A1/ko active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11131187A (ja) * | 1997-10-24 | 1999-05-18 | Kobe Steel Ltd | 迅速黒鉛化鋼および迅速黒鉛化鋼の製造方法 |
KR100349008B1 (ko) * | 1998-03-04 | 2002-08-17 | 신닛뽄세이테쯔 카부시키카이샤 | 냉간 단조용 강 및 그 제조방법 |
JPH11350066A (ja) * | 1998-06-04 | 1999-12-21 | Nkk Joko Kk | 被削性に優れた熱間鍛造鋼部品の製造方法及びその部品並びにそれに用いる熱間圧延鋼材 |
EP2530177A1 (en) * | 2010-01-25 | 2012-12-05 | Nippon Steel Corporation | Steel plate for cold forging and process for producing same |
KR102224044B1 (ko) * | 2018-12-18 | 2021-03-09 | 주식회사 포스코 | 흑연화 열처리용 선재와 흑연강 및 그 제조방법 |
Also Published As
Publication number | Publication date |
---|---|
EP4394072A1 (en) | 2024-07-03 |
CN118076760A (zh) | 2024-05-24 |
KR20230052013A (ko) | 2023-04-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR102224044B1 (ko) | 흑연화 열처리용 선재와 흑연강 및 그 제조방법 | |
KR102042063B1 (ko) | 흑연화 열처리용 강재 및 피삭성이 향상된 흑연강 | |
KR20060115628A (ko) | 항복비가 높은 소부경화형 냉연강판과 그 제조방법 | |
KR101657790B1 (ko) | 흑연화 열처리용 강재 및 피삭성 및 냉간단조성이 우수한 흑연강 | |
KR20200045906A (ko) | 절삭성 및 연자성이 우수한 흑연강 및 그 제조방법 | |
WO2023063678A1 (ko) | 절삭성능이 우수한 유황 첨가 흑연강 선재, 강선, 흑연강 및 그 제조방법 | |
KR101657792B1 (ko) | 흑연화 열처리용 강재 및 피삭성이 우수한 흑연강 | |
KR20200063385A (ko) | 구상화 열처리성이 우수한 선재 및 그 제조방법 | |
WO2023113430A1 (ko) | Tv 펨너트 부품용 흑연강 선재, 흑연강, 이의 제조 및 절삭 가공 방법 | |
CN112011740B (zh) | 一种高韧性高硬度模具钢及其制备方法 | |
WO2023113444A1 (ko) | 칼슘-함유 흑연강 선재, 흑연강, 이의 제조 및 절삭 가공 방법 | |
WO2021125793A1 (ko) | 우수한 수소취성 저항성을 가지는 고강도 냉간압조용 선재 및 그 제조방법 | |
WO2022131864A1 (ko) | 흑연화 열처리용 선재 및 흑연강 | |
WO2022131865A1 (ko) | 흑연화 열처리용 선재 및 흑연강 | |
WO2023113428A1 (ko) | 절삭성능이 우수한 칼슘-함유 흑연강 및 그 제조방법 | |
WO2013125760A1 (ko) | 고주파 열처리 후 초세립을 갖는 기계구조용 부품강 및 그 제조방법 | |
WO2020091277A1 (ko) | 연질화 열처리의 생략이 가능한 선재 및 그 제조방법 | |
WO2022131752A1 (ko) | 지연파괴 저항성이 향상된 선재, 부품 및 그 제조방법 | |
KR102528281B1 (ko) | 흑연화 열처리용 선재 및 흑연강의 제조 방법 | |
WO2022131589A1 (ko) | 열처리 특성 및 수소지연파괴 특성이 우수한 고강도 냉간압조용 선재, 열처리부품 및 이들의 제조방법 | |
KR20230039008A (ko) | Tv 펨너트 부품용 흑연강 선재, 강선, 흑연강 및 그 제조방법 | |
JP7445686B2 (ja) | 黒鉛化熱処理用線材と黒鉛鋼及びその製造方法 | |
KR20110004668A (ko) | 고Si 베어링강 및 고Si 베어링강의 구상화 열처리방법 | |
KR20230089719A (ko) | 절삭성능이 우수한 자동선반용 흑연강 선재, 강선, 흑연강 및 그 제조방법 | |
WO2021125408A1 (ko) | 구상화 열처리성이 우수한 선재 및 그 제조방법 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22881305 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022881305 Country of ref document: EP Ref document number: 22 881 305.1 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2022881305 Country of ref document: EP Effective date: 20240329 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |