HIGH-SPEED STEEL FOR COATING TOOL WHICH CAUSE LESS CRATER WEAR

摘要

PURPOSE:To develop a high-speed steel material for a coating tool which causes less crater wear by incorporating further Mo or Mo and Co to a high-speed steel having a specific carbon equiv. value. CONSTITUTION:A cutting tool formed of a coating high-speed steel consisting of a high-speed steel coated with a sintered hard TiN or TiC layer causes in some case a crater wear in the part where the base material of high-speed steel of the tool is exposed during use, resulting in chipping of the edge part coated with Tin, etc. Such crater wear is prevented by using the high-speed steel having the compsn. in which the carbon content C attains the value expressed by the expression (1) and which contains 3-5% Cr, 0-10% Mo, 0-20% W, 1-10% V, 0.2% N, where 10-30% W+2Mo and C-N=Ceq-0.1 or contains further 20% Co and consists of the balance Fe. The high-speed steel for a coating tool which causes less crater wear is obtd.