| 摘要 |
PURPOSE: To produce a tool steel excellent in wear resistance and machinability by immediately cooling at a specific cooling rate after applying high temp. soaking under a specific condition to the steel material for tool steel containing the specific ratio of C, Si, Mn and Cr. CONSTITUTION: The steel material for tool steel containing by wt.% of 1.0-1.4% C, 0.2-1.2% Si, <=2% Mn, 8.0-13.0% Cr as the basic componets is subjected to the high temp. soaking in the temp. range of 1150-1210 deg.C where melting phase is not developed and solid solution of the carbide can be formed, thereby only M7 C3 type carbide having high m.p. is remained and the solid solution of the other steel material is formed. Successively, the steel material is immediately cooled at >=10 deg.C/min cooling rate and the carbide is precipitated at the grain boundary and the tool steel having <=100μm the interval of M7 C3 type carbide and 90-105HRB Rockwell hardness so as not to form the network is produced. By this method, the tool steel capable of being utilized as the cold tool steel is obtd.
|
