| 摘要 |
PROBLEM TO BE SOLVED: To provide a tool steel for cold working, which includes a carbide of such an amount as not to deteriorate a fatigue resistance but to give a tool a satisfactory wear resistance, and gives along life with a superior strength. SOLUTION: This tool steel for cold working is characterized by including, by weight, C: 0.65-1.3%, Si: 2.0% or less, Mn: 0.1-2.0%, Cr: 5.0-13.0%, Mo and/or W: 0.5-5.0% as Mo equivalent (Mo+1/2W), V and/or Nb: 0.1-2.5% as V equivalent (V+1/2Nb), and the balance iron with inevitable impurities, and in that a retained austenic structure of 5-20% by volume % is forced to remain in a martensite structure of the steel. The tool steel for cold working is further characterized in that an agglomerated size of carbide agglomeration parts (parts of a ratio of a b/a of <=0.5 for distance between carbides) is 100μm or less or a size of carbide is 5-15μm, wherein, (a) represents the distance between the centers of gravity of individual carbide; and (b) the shortest distance between carbides.
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