| 摘要 |
PROBLEM TO BE SOLVED: To impart excellent surface rigidity to a product, at the time of producing table wear using an austenitic metal, by executing carburizing treatment after fluorination treatment and regulating the depth and hardness of a carbohardened layer and the formation of carbides in the carburized layer. SOLUTION: A base metal is composed of an austenitic stainless steel contg., by weight, 15 to 25% Cr or furthermore contg. 1.5 to 3% Mo. This is formed into a prescribed shape, which is thereafter subjected to carburizing treatment, and a carbohardened layer composed of austenitic phases is formed to a depth of 10 to 150μm from the surface in such a manner that there occurs no intrusion of carbon atoms into the base metal crystal lattice and no formation of solid solution, thus, to cause no formation of coarse chromium carbide grains. Furthermore, the micro Vickers hardness of this carbirized layer is regulated to 700 to 1,050. At the time of the carburizing treatment, it is subjected to fluorination treatment of executing holding under heating at 300 to 500 deg.C in a gaseous fluorine atmosphere, is thereafter subjected to heating treatment in a gas contg. NH3 and is then carburized in a carburizing gaseous atmosphere contg. carbon monoxide to regulate the maximum carburizing concn. to 1.2 to 2.6wt.%.
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