| 摘要 |
<p>The steel according to the invention is characterized in that, in order to keep its weight content of molybdenum below 0.45%, its chemical composition, besides the iron and the inevitable residual impurities that result from the smelting of the steel, corresponds to the following analysis, given as percentages by weight: 0.3≰C %≰0.5 0.20≰Mo %<0.45 0.4≰Mn %≰1.0 0.4≰Cr %≰2.0 0.04≰Ni %≰0.8 0.02≰Nb %≰0.045 0.03≰V %≰0.30 0.02≰Ti %≰0.05, with Ti>3.5 N 0.003≰B %≰0.005% S %≰0.015 P %≰0.015, and optionally 0.05≰Si %≰0.20; Al %≰0.05 and N %≰0.015. By cold forming a hot-rolled wire rod resulting from continuous casting, it is possible to obtain, after heat treatment,“ready-to-use”coined parts, such as cap screws for example for the automotive industry, that offer a tensile strength from 1200 to more than 1500 MPa while having a good hydrogen embrittlement resistance, and this with a specially controlled“raw material”production cost.</p> |
