STEEL HAVING EXCELLENT VIBRATION ATTENUATION PERFORMANCE AND METHOD OF MANUFACTURING THE SAME

摘要

Steel having a structure of ferrite and tempered martennite and exhibiting excellent vibration attenuation characteristic is manufactured by the steps of forming a solid Jolution of steel consisting essentially of 0.02 - 0.01% by weight of carbon: less than 0.6% by weight of silicon 0.5 - 1.5% by weight of manganese: eithel one or more of 5 - 15% by weight of chromium and 2 - 9% by weight of tungsten: either one or both of 0.03 - 2% by weight of aluminum and 0.1 - 5% by weight of cobalt, less than 1.5% by weight of copper if necessary and the balance consisting of iron: comprising heating and keeping for a desired time period the alloyed steel in a temperature range in which austenite and ferrite coexist; cooling the steel so sa to transform austenite to martensite; and tempering the steel at a temperature of from 400.degree.C to a temperature below a transformation point thus forming a structure of ferrite and martensite. Steel incorporating copper is suitable for precipitation hardening. Advantageously, the amount of the tempered martensite should be less than 60% by volume.