280 TECHNICAL INFORMATION QHeat Treatment for Steel Materials QHardness Test Methods and Applicable Parts Name Vickers Hardness (HV) Hardening Depth (mm) Strain Applicable Materials Typical Material Reference Through hardening 750 or Less Full Depth Varies according to materials. High Carbon Steel C>0.45% SKS3 SKS21 SUJ2 SKH51 SKS93 SK4 S45C ·Operation of heating copper to an appropriate temperature over transformation point and quickly cooling it in an appropriate medium in order to increase hardness or improve strength. ·Not applicable to long or precision parts, such as spindles, etc. Carburization 500 or Less Standard 0.5 Up to 2 Moderate Low Carbon Steel C<0.3% SCM415 SNCM220 ·Applicable to partial hardening ·Hardening depth should be specified on drawings. ·Applicable to precision parts. Induction Hardening 750 or Less 1~2 High Medium Carbon Steel C 0.3~0.5% S45C ·A surface hardening method that uses high frequency induction current to quickly heat and cool the steel surface. ·Applicable to partial hardening ·Expensive in small-volume lots. ·High fatigue resistance. Nitriding 900~1000 0.1~0.2 Low Nitriding Steel SACM645 ·A surface hardening method that forms hardening layer of hard nitride compounds on the steel surface ·Obtains highest degree of hardness among all hardening techniques. ·Fit for mass production. ·Applicable to spindles for sliding bearing. TUFFTRIDE is the trademark of Durferrit GmbH‚ Germany (salt bath process). Carbon Steel 500 Stainless Steel 1000 0.01~0.02 Low Steel Material S45C SCM415 SK3 Stainless Steel ·Tufftride is one of the nitriding methods called soft-nitriding (salt bath process). ·High fatigue resistance and abrasion resistance ·Same corrosion resistance as zinc plating. ·Not applicable to precision parts because of incapability of polishing after heat treatment. ·Applicable to oil free bearings. Bluing − − − Wire Rod SWP-B ·Low temperature annealing. ·Removes internal stress during forming to enhance elasticity. Testing Method Principle Applicable Heat-Treated Parts Features Reference Brinell Hardness ·A (steel or super hard alloy) ball indenter is used to indent the test surface. Hardness is given as a quotient divided by the surface area of the dent, computed from the diameter. ·Annealing ·Normalized parts ·Anchored materials ·Applicable to uneven materials and forged products because indent is large. ·Not applicable to small or thin specimens. JIS Z2243 Rockwell Hardness ·This standard or test load is applied via a diamond or ball indenter. Hardness is read on a tester. ·Hardening tempered parts ·Carburized surfaces ·Nitrided parts ·Thin sheets such as copper, brass, bronze, etc. ·Hardness value obtained quickly. ·Applicable to intermediate testing of actual products. ·Caution is required as there are 30 types. JIS Z2245 Shore Hardness ·The specimen is set on a table. A hammer is dropped from a uniform height. Hardness is based on how height the hammer bounces. ·Hardening tempered parts ·Nitrided parts ·Large carburized parts, etc. ·Extremely easy to operate and data can be obtained quickly. ·Applicable to large parts. ·Indent is kept shallow, therefore is applicable to actual products. ·Portable, because of compactness and light weight. JIS Z2246 Vickers Hardness ·Uses a diamond 136˚square pyramid indenter. Hardness value is obtained from the surface area of the dent, computed from the experimental load and the length of the diagonal lines of the dent. (Automatically calculated) ·This hardening layers by induction hardening, carburizing, nitriding, electrolytic plating, ceramic coating, etc. ·Hardening layer depth in carburized and nitrided parts. ·Applicable to small and thin specimens. ·Applicable to all materials because of diamond indenter. JIS Z2244 Materials Hardening and HardnessTest Methods
RkJQdWJsaXNoZXIy MTc2MTk0OA==