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
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/06—Surface hardening
• • 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
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47G—HOUSEHOLD OR TABLE EQUIPMENT
  • A47G21/00—Table-ware
• • 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 dining and / or serving cutlery made of a steel material, which is formed from a ferritic core with a substantially martensitic edge layer.
• the surface hardness of the surface layer determined by the hardness test according to Vickers HV3, is 30 to 300% greater than the smallest hardness of the core, measured also according to Vickers HV 3.
• Hardness processes have also become known in the prior art in which curing is carried out by means of a laser beam and / or electron beam.
• a steel material which consists of a ferritic core with a substantially martensitic edge layer.
• the edge layer may be formed on one or more sides or the core ummantelnd.
• the invention also includes embodiments in which the surface layer still has a small proportion of retained austenite, depending on the stored C and N content of the steel material.
• Essential for the invention is that between the surface hardness of the surface layer and the smallest hardness of the core, a hardness difference, measured according to Vickers HV 3, by at least 30 to 300%.
• the dining and / or serving cutlery according to the invention are further distinguished by the fact that they also have a difference in terms of the modulus of elasticity between the martensitic surface layer and the core of the material, regardless of the aforementioned hardness difference.
• the martensitic surface layer has an E-modulus, measured in kN / tnm 2 , which is 1 to 100% larger than the E-modulus of the core material.
• the core is left relatively elastic, i. is formed of a ferritic material which retains the intrinsic properties inherent in the untreated steel material and that then only the surface layer is formed so that here a difference in hardness or a difference of the modulus of elasticity, as described above, is set .
• the applicant could show that not only is there a very high elasticity of the dining and / or serving cutlery according to the invention, but also that a scratching of the surface can be largely avoided.
• the hardness difference between the surface hardness of the surface layer and the smallest hardness of the core is 80 to 250%, preferably 100 to 250%.
• the surface hardness of the martensitic surface layer in the range from 320 to 650 HV 3 and the smallest hardness of the core may preferably be in the range from 160 to 260 HV 3.
• Material core an E-module is present, with the proviso that the modulus of elasticity in the surface layer is greater by 1 to 50% than that of the core.
• the determination of the modulus of elasticity in kN / mm 2 was carried out at 20 ° C.
• the edge layer of the eating and serving cutlery of the invention is defined by a hardening depth (EHT), which leads from the smallest hardness of the core, measured according to HV 3 + 30%, to the surface of the surface layer.
• the hardening depth (EHT) can be in the range of 0.005 mm to 1.0 mm, preferably 0.01 mm to 0.4 mm and particularly preferably in the range of 0.01 to 0.3 mm.
• Another characteristic of the surface layer according to the invention is that the hardness and also the modulus of elasticity within the martensitic surface layer decreases starting from the surface in the direction of the core as defined above.
• the decrease in hardness or the modulus of elasticity can take place continuously and / or also gradient-wise.
• the largest contribution to the decrease in hardness or the modulus of elasticity lies in the near-surface region of the surface layer itself.
• the surface of the martensitic surface layer is roughened and / or matted.
• the surface roughness can be in the range of 1.5 ⁇ m to 4.0 ⁇ m.
• Roughnesses of 1.9 ⁇ m to 2.8 ⁇ m (Scotch tape) or 1.7 ⁇ m to 2.1 ⁇ m (brushed) are preferred.
• polished surfaces have a roughness of 0.8 ⁇ m to 1.3 ⁇ m.
• ferritic steels are: 1.4021, 1.4000, 1.4016, 1.4028, 1.4024, 1.4034 and 1.4116. Preference is given to the steels 1.4021 and 1.4016.
• a significant advantage of the dining and serving utensil according to the invention consists in the fact that a steel can be selected which has a relatively low hardness and thus a high elasticity and that the martensitic edge layer is then subsequently formed by the treatment method described below. The martensitic surface layer then results in a significant increase in hardness, while retaining the elastic core, which then achieves superior scratch and corrosion resistance properties.
• the surface of the surface layer has a microstructure, which is characterized by a higher grain size compared to untreated steels, as well as the fact that no chromium carbide precipitates are present at the grain boundaries.
• the invention basically includes all corresponding counterparts with respect to the dining and serving cutlery. conditions that are known to those skilled in the art. Examples are knives, spoons, forks, pastry and cake servers, makers, tongs and rugs.
• the formation of the martensitic surface layer can take place in the dining and serving cutlery according to the invention by a heat treatment, preferably by a so-called "embroidering.”
• embroidering of steel materials is known per se in the prior art and is described, for example, in EP 0 652 300 Al or in DE 40 33 706 described.
• FIG 1 shows both the hardness profile after a heat treatment on the example of steel grade 1.4016 in the form of a graph and in Figure Ib a cross section in the magnification 50: 1.
• a table spoon of the company WMF of steel grade 1.4016 has been stitched at temperatures of above 1050 0 C and quenched with nitrogen or deep-frozen and annealed.
• the material 1.4016, X7 chromium 17 is a ferritic
• the table spoon has a surface hardness of 594 HV 3.
• the Einhär- depth was in the example 106 microns.
• the calculation of the depth of hardening is carried out according to the invention in such a way that the lowest hardness of the core, also measured in HV 3 + 30%, is also assumed.
• the output value is 240 HV 3.
• Figure Ib shows very clearly the microstructure, from which the martensitic boundary layer can be seen and the essentially ferritic core.
• the treated surface has an average grain diameter of 28 to 40 .mu.m measured by the average blade method.
• the grain diameter of the treated part is in the core at 15 to 20 microns and the untreated starting material at 10 to 14 microns linear.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Table Equipment (AREA)
• Heat Treatment Of Articles (AREA)
• Cookers (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
• Materials For Medical Uses (AREA)
• Heat Treatments In General, Especially Conveying And Cooling (AREA)
• Knives (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38267621

Family Applications (1)

Country Status (13)

Cited By (2)

Families Citing this family (5)

Citations (5)

Family Cites Families (13)

• 2007
  • 2007-02-02 PL PL07002295T patent/PL1956099T3/pl unknown
  • 2007-02-02 EP EP07002295A patent/EP1956099B1/de active Active
  • 2007-02-02 ES ES07002295T patent/ES2322207T3/es active Active
  • 2007-02-02 AT AT07002295T patent/ATE429519T1/de active
  • 2007-02-02 DE DE502007000645T patent/DE502007000645D1/de active Active
• 2008
  • 2008-01-29 CN CN200880003667XA patent/CN101627136B/zh active Active
  • 2008-01-29 CA CA2676987A patent/CA2676987C/en active Active
  • 2008-01-29 JP JP2009547589A patent/JP5418909B2/ja active Active
  • 2008-01-29 BR BRPI0807120-9A2A patent/BRPI0807120A2/pt active IP Right Grant
  • 2008-01-29 WO PCT/EP2008/000680 patent/WO2008092640A1/de not_active Ceased
  • 2008-01-29 EP EP08707381A patent/EP2115175A1/de not_active Withdrawn
  • 2008-01-29 KR KR1020097018029A patent/KR101302051B1/ko active Active
  • 2008-01-29 RU RU2009132197/02A patent/RU2456906C2/ru active
  • 2008-01-29 US US12/449,233 patent/US8349094B2/en active Active

Patent Citations (5)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events