高钢级管线钢中有效晶粒尺寸及与CVN关系研究

Study on Effective Particle Size of High Grade Pipeline Steels and Relationship Between CVN

利用EBSD对系列高钢级管线钢(如X65,X70,X80)影响其韧性的晶体学参数进行了研究,发现高钢级管线钢中对材料韧性起到积极作用的是晶界取向差大于15°的晶粒,而且研究大于35°取向差的晶粒对管线钢的参数研究是没有意义的;有效晶粒尺寸、晶界取向差频度分布、大角度晶界对小角度晶界比率是高钢级管线钢研究的重要参数;晶粒尺寸越细、有效晶粒越小、高角度(大于50°)晶粒频度越高,高钢级管线钢的韧性越好。

The parameters which affect toughness of the high grade pipeline steels were studied by using EBSD. It was shown that the grains had higher grain boundary orientation than 15° would be helpful to toughness of materials, when grain boundary orientation higher than 35°, it was useless to the parameters study of pipeline steels. The effective particle size, the frequency distribution of grain boundary orientation and the ratio of higher grain boundary to low grain boundary were important parameters in high grade pipeline study; The finer the grain size, the smaller the effective particle size, and the higher the frequency of grains boundary of higher than 50°, would effectively lead to the excellent toughness of high grade pipeline steels.