LEAD FREE STEEL AND METHOD OF MANUFACTURING

摘要

An essentially lead free steel having, in percent by weight (wt-%): Carbon: 0.39-0.43%; Manganese: 0.75-1.00%; Silicon: 0.15-0.35%; Chromium: 0.80-1.05%; Molybdenum: 0.15-0.25%; at least one of Tellurium: 0.003-0.090 wt-%, Selenium: 0.080-0.2 wt-%, Sulfur: 0.065-0.09% wt-%, and Bismuth: 0.03-0.1 wt-%; and the balance being Fe and normally occurring scrap steel impurities. A method for manufacturing an essentially lead free steel by subjecting a hot-rolled steel product to a heat treatment in which the steel product is subjected to a first temperature for a first duration; the steel product is subjected to a second temperature for a second duration, wherein the second temperature is less than the first temperature; and the steel product is subjected to a third temperature for a third time period, wherein the third temperature is greater than the second temperature; and cooling the steel product. After the heat treatment the steel is cold worked to the desired size.

主权项

1. A steel product that is essentially lead free, wherein the steel product comprises:
carbon in a range of 0.2 to 0.6 wt-%; manganese in a range of 0.6 to 1.1 wt-%; silicon in a range of 0.1 to 0.4 wt-%; chromium in a range of 0.6 to 1.2 wt-%; molybdenum in a range of 0.1 to 0.3 wt-%; at least one or more of:
tellurium in a range of 0.001 to 0.12 wt-%;selenium in a range of 0.05 to 0.25 wt-%;sulfur in a range of 0.4 to 0.12 wt-%; orbismuth in a range of 0.01 to 0.15 wt-%; balance being Fe and normally occurring scrap steel impurities; and wherein the steel product is subjected to a heat treatment process during which the steel product is subjected to:
a first temperature for a first duration;a second temperature for a second duration, wherein the second temperature is less than the first temperature;a third temperature for a for a third time period, wherein the third temperature is greater than the second temperature; andcooled after the third temperature.