摘要
通过低碳微合金化的思路设计了Q125级ERW石油套管钢的成分,同时研究了调质热处理工艺对其组织和性能的影响。结果表明,采用920℃淬火+500℃回火调质处理后,Q125石油套管钢的屈服强度为975 MPa,抗拉强度990 MPa,伸长率为14.8%,0℃冲击功为43 J,具有良好综合力学性能和耐蚀性。通过电子背散射衍射(EBSD)分析发现,调质后以大角度晶界为边界的平均晶粒尺寸得到明显细化;扫描电镜及透射电镜分析显示,试验钢的组织为典型的回火索氏体,内含有50～160 nm残留的马氏体/贝氏体板条,且板条呈平束状或交错排列,板条内部存在对强度贡献较大的相互缠结的高密度位错亚结构。
Effects of heat treatment process on microstructure and mechanical properties of the low carbon micro-alloyed Q125 REW oil casing steel were investigated.Quenched at 920 ℃ and tempered at 500 ℃,the Q125 steel exhibits outstanding corrosion resistance and mechanical properties with yield strength of 975 MPa,tensile strength of 990 MPa,elongation of 14.8% and the Charpy-V impact energy of 43 J tested at 0 ℃.Average grain size of large angle grain boundary of the steel quenched and tempered was significantly refined under EBSD.By means of SEM and TEM,the microstructure of the steel quenched and tempered is typical tempered sorbite retaining the morphology of martensite/bainite laths with width of 50-160 nm in packet and stagger arrangement.Further analysis by TEM found there were a lot of sub-structures with high density and tangled dislocation in the martensite/bainite laths which can help to improve the strength.
出处
《金属热处理》
CAS
CSCD
北大核心
2012年第11期16-19,共4页
Heat Treatment of Metals
基金
国家科技重大专项(2011ZX05016-004)
