Sintering and properties of MIM M2 high speed steel produced by prealloy and master alloy routes

The advantages of powder metallurgical processing of tool steels have been recognized for many years with water atomized [1] powder being used in press & sinter valve seat parts for many years and gas atomized tool steel powders consolidated by HIP used in high performance applications [2]. While coarse HIP powder grades dominate high volume tool steel markets, the advent of fine powder gas atomization has enabled the use of MIM for the production of an increasing number of industrial components where hardness and wear resistance is required. Examples include hand- and power-tool components, pump impellers and textile machinery. Tool steels typically have carbon content in the range 0.5–1.5% and heat treatment cycles are carefully controlled to achieve the optimum distribution of matrix carbides to deliver required wear performance.