CHROMIUM-MOLYBDENUM CAST STEEL EXCELLENT IN MACHINABILITY

摘要

PROBLEM TO BE SOLVED: To obtain a cast steel excellent in mechanical properties, such as strength and wear resistance, by specifying the composition of a chromium- molybdenum cast steel. ;SOLUTION: This chromium-molybdenum cast steel has a composition consisting of, by mass, 0.1-0.5% C, 0.15-1.0% Si, 0.3-1.0% Mn, 0.90-1.50% Cr, 0.1-0.5% Mo, 0.005-1.0% Ti, 0.01-0.1% Al, and the balance Fe. This chromium- molybdenum cast steel has excellent turning and planing properties at (0.1 to 1.2)m/s cutting rate. The reasons why contents of the elements in the composition are regulated to the values in the above ranges are as follows: C, to secure strength and machinability; Si, to secure deoxidation, flowability of molten metal, castability, and toughness; Mn, to secure deoxidation, mechanical properties by improvement of hardenability, and wear resistance; Cr, to secure wear resistance and hardenability; Mo, to secure strength, such as high temp. creep resistance, and wear resistance; Ti, to refine structure and secure softening control after hot working; Al, to refine structure.;COPYRIGHT: (C)1997,JPO