US20160145705A1 - Wear-resistant, partially uncoated steel parts and methods of producing same - Google Patents
Wear-resistant, partially uncoated steel parts and methods of producing same Download PDFInfo
- Publication number
- US20160145705A1 US20160145705A1 US14/903,022 US201414903022A US2016145705A1 US 20160145705 A1 US20160145705 A1 US 20160145705A1 US 201414903022 A US201414903022 A US 201414903022A US 2016145705 A1 US2016145705 A1 US 2016145705A1
- Authority
- US
- United States
- Prior art keywords
- hardening
- steel
- wear
- resistant
- semifinished
- 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.)
- Abandoned
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 77
- 239000010959 steel Substances 0.000 title claims abstract description 77
- 238000000034 method Methods 0.000 title claims description 22
- 238000005065 mining Methods 0.000 claims abstract description 9
- 230000009466 transformation Effects 0.000 claims abstract description 9
- 238000010438 heat treatment Methods 0.000 claims description 20
- 238000005121 nitriding Methods 0.000 claims description 18
- 239000000463 material Substances 0.000 claims description 15
- 238000004519 manufacturing process Methods 0.000 claims description 10
- PALQHNLJJQMCIQ-UHFFFAOYSA-N boron;manganese Chemical compound [Mn]#B PALQHNLJJQMCIQ-UHFFFAOYSA-N 0.000 claims description 5
- 229910000712 Boron steel Inorganic materials 0.000 claims description 3
- 229910000794 TRIP steel Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910000885 Dual-phase steel Inorganic materials 0.000 claims description 2
- 238000005255 carburizing Methods 0.000 claims 1
- 239000003082 abrasive agent Substances 0.000 abstract description 8
- 235000019589 hardness Nutrition 0.000 description 26
- 230000008569 process Effects 0.000 description 14
- 238000005261 decarburization Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 229910000760 Hardened steel Inorganic materials 0.000 description 5
- 229910000734 martensite Inorganic materials 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910000922 High-strength low-alloy steel Inorganic materials 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 229910001338 liquidmetal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
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
- C21D9/0068—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
-
- 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
- C21D1/06—Surface hardening
-
- 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
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- 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
- C21D1/62—Quenching devices
- C21D1/673—Quenching devices for die quenching
-
- 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
-
- 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
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/22—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for drills; for milling cutters; for machine cutting tools
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
- C23C8/22—Carburising of ferrous surfaces
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/24—Nitriding
- C23C8/26—Nitriding of ferrous surfaces
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/80—After-treatment
-
- 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
- C21D2221/00—Treating localised areas of an article
- C21D2221/02—Edge parts
-
- 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
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
-
- 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
- C21D9/18—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for knives, scythes, scissors, or like hand cutting tools
Definitions
- the invention relates to a wear-resistant, at least partly uncoated steel part consisting of a hardenable steel grade which has been produced from a semifinished part by hot forming and/or hardening.
- the invention relates to a process for producing a wear-resistant, at least partly uncoated processing, conveying and/or crushing means of agricultural machines, conveying machines, mining machines or building machines from a semifinished part, in which the semifinished part is heated to a temperature above the Ac1 transformation temperature and is subsequently hot formed and/or hardened.
- Wear-resistant, at least partly uncoated steel parts which have to have high strengths and at the same time are subjected to abrasive forces are required, for example, for the production of agricultural machines, in particular plows, and also for buckets of a dredge or conveying screws for abrasive materials, for example the conveying screw of a concrete mixer.
- the parts are preferably subjected to hot forming in which the semifinished parts from which the steel parts are produced are firstly heated to a temperature above the Ac1 transformation temperature point, so that transformation hardening of the microstructure is effected by hot forming and subsequent hardening, i.e.
- the martensitic microstructure has a significantly greater hardness but also a significantly greater mechanical strength, for example tensile strength.
- Corresponding steel parts are known, for example, from the German patent DE 10 2010 050 499 B3.
- the German patent describes a process for producing dredger buckets, concrete mixer conveying screws, conveying screw blades or other transport blades of conveying plants, in which the components are hot formed and press hardened.
- the German first publication DE 10 2010 017 354 A1 is concerned with the problem of hot forming of zinc-plated flat steel products to produce high-strength or very high-strength steel components.
- the melting point of the metal of the protective coating is exceeded, there is a risk of “liquid metal embrittlement” which is caused by penetration of the molten metal of the coating into the notches or cracks arising in forming of the flat steel product.
- the liquid metal which has penetrated into the steel substrate deposits at grain boundaries and there reduces the maximum tensile or compressive stress which can be withstood.
- the patent publication offers nitriding of the outer layer regions, so as to produce finely structured outer layer regions.
- the present invention is, in contrast, concerned with the problem that hot-formed and/or hardened steel parts do not have the desired wear resistance in the uncoated regions and are therefore not optimally suited for use as conveying means, for example on contact with abrasive materials. It is therefore an object of the present invention to propose at least partly uncoated steel parts having improved suitability for use with abrasive materials. In addition an inexpensive production process for corresponding steel parts should be proposed.
- the object indicated is achieved, for a steel part, the steel part at least partially having a surface region which has been hardened to a depth of not more than 100 ⁇ m, preferably to a depth of up to 40 ⁇ m, by surface hardening before hot forming and/or hardening.
- the hardened surface region of the steel part is hardened by carburization or nitriding. Both processes offer the opportunity of hardening regions close to the surface of the steel part in a targeted manner before hot forming or hardening.
- nitriding has the advantage that the hardness is not reduced during hot forming. In the case of carburization, the carbon content in the surface regions is increased but decreases again due to hot forming.
- the hardened surface region of the steel part preferably has at least the hardness of the base material of the steel part located under the surface region.
- the wear resistance of the steel part can preferably also be improved by the hardness of the surface region of the steel part being greater than the hardness of the base material. It has been found that, in particular, the hardness of the surface regions is responsible for the wear resistance of the steel part on contact with highly abrasive materials, so that a very wear-resistant steel part can be produced even when using a somewhat softer base material.
- the steel part is, according to a further embodiment of the steel part, configured for use as processing, conveying and/or crushing means in agricultural machines, conveying machines, mining machines or building machines, with at least the regions of the steel part which are subjected to abrasive forces being surface-hardened.
- manganese-boron steels dual-phase steels or TRIP steels, in which particularly pronounced martensite formation or transformation of residual austenitic components into martensite makes an increase in the hardnesses possible, are also particularly advantageous.
- the surface region of the steel part which has been hardened before hot forming and/or hardening has, at least in regions, a hardness of from 400 to 700 HV. These values are generally achieved only by very high-strength steel grades after hot forming or hardening in the base material.
- the surface hardening before hot forming or hardening offers, in particular, the opportunity of providing the starting material for production of the steel components on a coil.
- the abovementioned object is achieved by a process for producing a wear-resistant, at least partly uncoated steel part for processing, conveying and/or crushing means of agricultural machines, conveying machines, mining machines or building machines from a semifinished part, in which the semifinished part is heated, at least in regions, to a temperature above the Ac1 transformation temperature and is subsequently hot formed and/or hardened, in that the semifinished part at least partially is subjected to surface hardening in which a surface region is hardened to a depth of not more than 100 ⁇ m before hot forming and/or hardening.
- the depth of the surface region which is to be hardened is controlled by the duration of the hardening treatment. It has been found, in particular, that despite heating to a temperature above the Ac1 transformation temperature point, the surface-hardened regions of the steel part remain stable in respect of the surface hardness, so that high surface hardness can be achieved after hot forming and/or hardening. This leads to the steel parts of processing, conveying and/or crushing means of agricultural machines, conveying machines, mining machines or building machines which are in contact with abrasive materials displaying reduced wear.
- the hardening of the surface regions before hot forming or before hardening makes it possible to carry out the surface hardening on coilable materials, i.e. on steel strip, so that particularly economical production of wear-resistant, at least partly uncoated steel parts from semifinished parts is made possible.
- hardening of the surface region is effected by nitriding or by carburization. Both processes make it possible to provide a higher hardness in the surface region, which after hot forming and/or after hardening make a higher wear resistance of the surface of the hot-formed or hardened steel part possible.
- the surface hardening is, in a further embodiment, particularly preferably carried out by a heat treatment in a heat treatment atmosphere comprising up to 25% by volume of H 2 , 0.1-10% by volume of NH 3 , H 2 O and a balance N 2 and also unavoidable impurities at a holding temperature of from 600° C. to 900° C.
- the dew point of the heat treatment atmosphere is preferably in the range from ⁇ 50° C. to ⁇ 5° C., so that the effect of atmospheric moisture on the hardening process is reduced.
- preference is given to a maximum of 10% by volume of H 2 and a maximum of 5% by volume of NH 3 being permitted and the dew point being set to a dew point temperature of from ⁇ 40° C. to ⁇ 15° C. at a temperature of from 680 to 840° C.
- the latter process parameters gave improved and more uniform surface hardening.
- the depth of the surface hardening can be set via the time for which the holding temperature is maintained.
- the time for which the semifinished part has the holding temperature during surface hardening is preferably set to from 5 s to 600 s, preferably from 30 s to 120 s.
- the surface hardening is preferably carried out in a continuous hardening furnace, so that, for example, a strip-like semifinished part, i.e. a coilable semifinished part, is also surface-hardened and can be fed to the further hot forming and/or press hardening steps.
- a strip-like semifinished part i.e. a coilable semifinished part
- surface hardening in a chamber furnace is also conceivable.
- semifinished parts such as manganese-boron steels, dual-phase steels and TRIP steels firstly display a particularly high strength increase during hot forming or during hardening and secondly provide the opportunity of bringing the regions close to the surface to identical hardness in the range from 400 to 700 HV by nitriding.
- steel parts which are very wear-resistant and have particularly high strengths can be produced inexpensively.
- FIG. 1 schematically shows an example of the process for producing a wear-resistant, at least partly uncoated steel part
- FIG. 2 shows the layer structure of the semifinished part or steel part treated as per the example in FIG. 1 in a schematic illustration
- FIGS. 3, 4 shows examples of a steel part for agricultural machines and conveying machines
- FIG. 5 shows a graph of the hardness profile as a function of the distance from the surface for two examples and a comparative example.
- FIG. 1 firstly shows, very schematically, an example of the production of a wear-resistant, at least partly uncoated steel part in a schematic illustration.
- the semifinished part 1 which consists of a steel, for example a manganese-boron steel, dual-phase steel or TRIP steel, is firstly fed to surface hardening 2 . If a strip-like semifinished part is reeled off a coil 1 a and fed to surface hardening 2 , it is, for example, advantageous to carry out surface hardening, for example in the case of nitriding, in a continuous hardening furnace at the end of which, for example, the strip-like semifinished part 1 , now provided with a hardened surface, can be wound up on a coil (not shown).
- the surface-hardened strip-like semifinished part is cut to length and fed to hot forming and/or hardening 3 , so that process step 3 can produce a formed, at least partly uncoated steel part 4 which is suitable for processing, conveying and/or crushing means of agricultural machines, conveying machines, mining machines or building machines.
- the steel part 4 produced in this way characterizes high strength values owing to the hot forming and/or hardening step.
- the surface region of the steel part also has an increased hardening due to the nitriding of the surface which has taken place before hot forming and/or before hardening.
- the process of the invention enables the decarburization of the surface regions, which takes place to a depth of 100 ⁇ m, to be countered by the surface region being surface-hardened to a depth of 100 ⁇ m or in a region down to a depth of 40 ⁇ m.
- the surface hardening is preferably carried out by nitriding.
- carburization of the surface region is also conceivable.
- the surface hardening in process step 2 is preferably carried out by means of a heat treatment in a heat treatment atmosphere comprising up to 25% by volume of H 2 , 0.1-10% by volume of NH 3 , H 2 O and balance N 2 and also unavoidable impurities at a holding temperature of from 600° C. to 900° C. Reduction of the hydrogen concentration to a maximum of 10% by volume or limiting of the NH 3 concentration to a maximum of 5% by volume also leads to a further improvement of the nitriding result.
- the depth of the surface hardening can be set via the duration of the surface hardening, for example at a holding temperature of from 5 s to 600 s.
- the surface is preferably nitrided at a holding temperature of from 30 s to 120 s, with the temperature being from 680° C. to 840° C.
- Carrying out the surface hardening before hot forming or hardening has the advantage that a heat treatment process can be carried out significantly more efficiently using a, for example, strip-like semifinished part in a continuous hardening furnace or a plate in a continuous hardening furnace than when using formed steel parts which have different shapes and different geometries.
- the quality of the surface hardening can likewise be ensured more easily by the use of strip-like semifinished parts or semifinished parts configured as a blank.
- FIG. 2 then schematically shows a cross section of the semifinished part at three different points in time during the process.
- the semifinished part 1 has a more or less homogeneous, for example ferritic microstructure 1 a corresponding to the production process, which is determined by the combination of production process and steel composition.
- the surface region lb is hardened by inward diffusion of nitrogen in the case of nitriding or carbon in the case of carburization, with the microstructure changing there.
- the thickness of the surface region 1 b depends on the duration of the heat treatment.
- the surface region is usually up to a maximum of 100 ⁇ m in which the hardness of the semifinished part is altered.
- a preferred region which is a compromise between sufficient surface hardening and duration of the heat treatment for surface hardening, has a thickness of from 20 to 40 ⁇ m.
- the duration of surface hardening is then preferably from 30 s to 120 s.
- the microstructure of the material 1 a remaining underneath the surface region 1 b remains essentially unchanged during the heat treatment.
- the microstructure of the base material 1 a is then firstly converted into austenite and, by means of hardening, later partially into martensite. In this way, high hardness and good mechanical strengths are achieved in the base material 1 c .
- the surface region 1 b remains unchanged except for carburization of these layers. As a result of nitriding, the surface region can continue to remain hardened. In the case of targeted carburization of the surface region 1 b instead of nitriding, decarburization can be countered, so that an increase in the hardness is also achievable here.
- the formed steel part 4 thus has a hardened region 1 b and also a region 1 c which has been hardened by the hot forming and hardening.
- FIGS. 3 and 4 show typical fields of application for the wear-resistant, at least partially uncoated steel part in the form of a conveying screw 5 in FIG. 3 and a plowshare 6 for agricultural plows in FIG. 4 .
- Both components are typical representatives of processing, conveying and/or crushing means which are used in agricultural machines, conveying machines, mining machines or building machines, for example concrete mixers, and are exposed to highly abrasive materials.
- the use of hot formed and/or press hardened steel parts has hitherto not been very advantageous because of the increased susceptibility to wear. Due to the surface hardening of the region which is decarburized during hot forming and/or hardening, the hot forming steels gain an enlarged range of uses.
- Table 1 shows measurements of the hardness of samples A and B which consist of a steel of grade 22MnB5.
- the samples A and B were subjected to surface nitriding in a heat treatment atmosphere comprising 1% by volume of NH 3 or 4% by volume of NH 3 at 760° C. and 90 s in each case.
- the surface nitriding was carried out at inter-critical temperatures (T>Ac1) since austenite can dissolve more nitrogen than ferrite.
- the samples were subsequently hot formed and hardened. Polished sections were made from the hot formed or hardened steel parts and the hardness HV 0.01 (DIN EN ISO 6507-1) was measured at a distance of 5 ⁇ m from the surface.
- the microhardness measurement on the samples as a function of the content of NH 3 in the heat treatment atmosphere had a greater hardness at a higher NH 3 content of the heat treatment atmosphere at the same heat treatment parameters, i.e. hold time and hold temperature.
- sample A firstly decreases from the value of 460 HV measured at the surface to a value of 333 HV at a depth of 20 ⁇ m. The hardness then increases again to a value of about 492 HV, which indicates that the decarburization of the base material ceases here.
- the uppermost region, in particular, from 5 to 15 ⁇ m was significantly hardened by the surface hardening. It can be seen from sample B that the surface hardening is more pronounced, both in terms of the amplitude and the depth of hardening, at an increased NH 3 content. This can be attributed to greater diffusion of nitrogen into the surface of the steel part taking place due to the higher NH 3 concentration in the heat treatment atmosphere.
- sample B start at 546 at a depth of 5 ⁇ m and decrease to a value of 394 at a depth of 25 ⁇ m.
- the values subsequently increase again to about 466 at a depth of 45 ⁇ m. It can clearly be seen that the surface is harder than the base material at a depth of 45 ⁇ m.
- FIG. 5 A similar picture is shown by the measurements on two further examples shown in FIG. 5 compared to a comparative example.
- the comparative example illustrated by a dotted line displays a reduced hardness below 400 HV 1 (DIN EN ISO 6507-1) in the region of 5 to 35 ⁇ m.
- the reduction in the hardness compared to the base material, which is in the range from 450 HV 1 to 500 HV 1, is explained by decarburization during hot forming.
- the two comparative examples with two different nitriding variants, once again 1% strength NH 3 heat treatment atmosphere or 4% strength NH 3 heat treatment atmosphere, differ especially in this region close to the surface, since hardness of above 500 could be measured here.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Heat Treatment Of Articles (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102013107100.7 | 2013-07-05 | ||
DE102013107100.7A DE102013107100A1 (de) | 2013-07-05 | 2013-07-05 | Verschleißfestes, zumindest teilweise unbeschichtetes Stahlteil |
PCT/EP2014/063259 WO2015000740A1 (de) | 2013-07-05 | 2014-06-24 | Verschleissfestes, zumindest teilweise unbeschichtetes stahlteil |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160145705A1 true US20160145705A1 (en) | 2016-05-26 |
Family
ID=51059430
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/903,022 Abandoned US20160145705A1 (en) | 2013-07-05 | 2014-06-24 | Wear-resistant, partially uncoated steel parts and methods of producing same |
Country Status (9)
Country | Link |
---|---|
US (1) | US20160145705A1 (de) |
EP (1) | EP3017074B1 (de) |
JP (1) | JP2016528381A (de) |
KR (1) | KR20160029102A (de) |
CN (1) | CN105358720A (de) |
CA (1) | CA2916155C (de) |
DE (1) | DE102013107100A1 (de) |
ES (1) | ES2704437T3 (de) |
WO (1) | WO2015000740A1 (de) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102016200912A1 (de) | 2016-01-22 | 2017-07-27 | Thyssenkrupp Ag | Verschleißschutzelement für eine Zerkleinerungseinrichtung |
EP3533886A4 (de) * | 2016-10-31 | 2020-04-01 | Nippon Steel Corporation | Verfahren zur herstellung eines stahlelements und stahlelement |
DE102020116126A1 (de) * | 2020-06-18 | 2021-12-23 | Bilstein Gmbh & Co. Kg | Verfahren zum Presshärten von warmumformbaren Platinen |
CN112589393B (zh) * | 2020-12-14 | 2022-10-11 | 舟山中南锚链有限公司 | 一种锚链的生产工艺 |
CN113529009A (zh) * | 2021-07-07 | 2021-10-22 | 江苏大学 | 一种硼钢的热处理方法、高强韧硼钢及其应用 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102010017354A1 (de) * | 2010-06-14 | 2011-12-15 | Thyssenkrupp Steel Europe Ag | Verfahren zum Herstellen eines warmgeformten und gehärteten, mit einer metallischen Korrosionsschutzbeschichtung überzogenen Stahlbauteils aus einem Stahlflachprodukt |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DD78385A (de) * | ||||
CA2037316C (en) * | 1990-03-02 | 1997-10-28 | Shunichi Hashimoto | Cold-rolled steel sheets or hot-dip galvanized cold-rolled steel sheets for deep drawing |
JPH08109466A (ja) * | 1994-10-11 | 1996-04-30 | Nippon Steel Corp | 鋼板の窒化方法 |
JP2000204464A (ja) * | 1999-01-12 | 2000-07-25 | Komatsu Ltd | 表面処理歯車とその製造方法、製造装置 |
DE102006001198A1 (de) * | 2006-01-10 | 2007-07-12 | Sms Demag Ag | Verfahren und Vorrichtung zur Einstellung gezielter Eigenschaftskombinationen bei Mehrphasenstählen |
JP4762077B2 (ja) * | 2006-08-09 | 2011-08-31 | 日本パーカライジング株式会社 | 鉄鋼部材の焼入れ方法、焼入れ鉄鋼部材及び焼入れ表面保護剤 |
JP2011032536A (ja) * | 2009-07-31 | 2011-02-17 | Neturen Co Ltd | 焼入れ鉄鋼部材の複合熱処理方法及び焼入れ鉄鋼部材 |
DE102009049398C5 (de) * | 2009-10-14 | 2015-05-07 | Benteler Automobiltechnik Gmbh | Verfahren zur Herstellung eines Strukturbauteils für ein Kraftfahrzeug und Strukturbauteil |
DE102010050499B3 (de) | 2010-11-08 | 2012-01-19 | Benteler Automobiltechnik Gmbh | Verwendung eines verschleißfesten Stahlbauteils |
DE102012001862B4 (de) * | 2012-02-01 | 2015-10-29 | Benteler Defense Gmbh & Co. Kg | Verfahren zur Herstellung eines Panzerungsbauteils und Panzerungsbauteil |
-
2013
- 2013-07-05 DE DE102013107100.7A patent/DE102013107100A1/de not_active Withdrawn
-
2014
- 2014-06-24 KR KR1020167002943A patent/KR20160029102A/ko unknown
- 2014-06-24 CA CA2916155A patent/CA2916155C/en not_active Expired - Fee Related
- 2014-06-24 ES ES14734430T patent/ES2704437T3/es active Active
- 2014-06-24 WO PCT/EP2014/063259 patent/WO2015000740A1/de active Application Filing
- 2014-06-24 US US14/903,022 patent/US20160145705A1/en not_active Abandoned
- 2014-06-24 JP JP2016522440A patent/JP2016528381A/ja active Pending
- 2014-06-24 CN CN201480038539.4A patent/CN105358720A/zh active Pending
- 2014-06-24 EP EP14734430.3A patent/EP3017074B1/de active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102010017354A1 (de) * | 2010-06-14 | 2011-12-15 | Thyssenkrupp Steel Europe Ag | Verfahren zum Herstellen eines warmgeformten und gehärteten, mit einer metallischen Korrosionsschutzbeschichtung überzogenen Stahlbauteils aus einem Stahlflachprodukt |
US20130206284A1 (en) * | 2010-06-14 | 2013-08-15 | Thyssenkrupp Steel Europe Ag | Method for Producing a Hot-Formed and Hardened Steel Component Coated with a Metallic Anti-Corrosion Coating from a Sheet Steel Product |
Also Published As
Publication number | Publication date |
---|---|
CA2916155A1 (en) | 2015-01-08 |
ES2704437T3 (es) | 2019-03-18 |
EP3017074B1 (de) | 2018-10-17 |
WO2015000740A1 (de) | 2015-01-08 |
CN105358720A (zh) | 2016-02-24 |
CA2916155C (en) | 2017-11-07 |
EP3017074A1 (de) | 2016-05-11 |
KR20160029102A (ko) | 2016-03-14 |
JP2016528381A (ja) | 2016-09-15 |
DE102013107100A1 (de) | 2015-01-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101820273B1 (ko) | 프레스 경화용 강 시트의 제조 방법, 빛 이 방법에 의해 획득되는 부품 | |
US20160145705A1 (en) | Wear-resistant, partially uncoated steel parts and methods of producing same | |
JP6788612B2 (ja) | 平鋼製品およびその製造方法 | |
JP5315790B2 (ja) | 耐遅れ破壊特性に優れた高強度pc鋼線 | |
US9260775B2 (en) | Low alloy steel carburization and surface microalloying process | |
KR101122840B1 (ko) | 침탄 켄칭성이 우수한 탄소 강판 및 그 제조 방법 | |
CN109477182B (zh) | 高强度钢板及其制造方法 | |
KR20140064929A (ko) | 볼트용 강선 및 볼트, 및 그의 제조 방법 | |
US11047036B2 (en) | Method of fabricating a nitrided low-alloy steel part | |
KR101843704B1 (ko) | 도금성, 가공성 및 내지연파괴특성이 우수한 고강도 도금 강판, 및 그의 제조 방법 | |
US20140334966A1 (en) | Hot-rolled steel sheet for nitriding, cold-rolled steel sheet for nitriding excellent in fatigue strength, manufacturing method thereof, and automobile part excellent in fatigue strength using the same | |
JP2016003395A (ja) | 優れた特性を有している表面処理機械部品用鋼、並びにその鋼の部品及びその製造方法 | |
KR101733513B1 (ko) | 질화 처리용 강판 및 그의 제조 방법 | |
CN105899699A (zh) | 钢材及其制造方法 | |
KR20240000646A (ko) | 구멍 확장비가 높은 열간 압연된 강 시트 및 이의 제조 방법 | |
JP2000063998A (ja) | 無段変速機ベルト用準安定オ―ステナイト系ステンレス鋼板およびその製造方法 | |
WO2011115255A1 (ja) | ばね用鋼および鋼材の表面処理方法 | |
Alava et al. | On the influence of cryogenic steps on heat treatment processes | |
JP6438253B2 (ja) | 遊技用鋼球およびその製造方法 | |
US20230136145A1 (en) | Method for producing a screw, and screw | |
Radionova et al. | The study of aging cold rolled and hot dip galvanized automotive steel | |
WO2022242859A1 (en) | Method for manufacturing a high strength steel plate and high strength steel plate | |
MX2023013724A (es) | Hoja de acero galvanizada por inmersion en caliente aleada de alta resistencia y metodo de fabricacion de la misma. | |
Gureev et al. | Influence of laser tempering on the characteristics of surface layers of tool steels | |
JP2004100018A (ja) | Cu析出硬化型高強度鋼材およびその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: THYSSENKRUPP STEEL EUROPE AG, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SIKORA, SASCHA;BANIK, JANKO;WUTTKE, THIEMO;SIGNING DATES FROM 20160111 TO 20160112;REEL/FRAME:038631/0556 |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |