X90高强度管线钢的组织与性能

Microstructure and mechanical properties of X90 high strength pipeline steel

借助SEM和电子背散射衍射(EBSD)技术对一种低合金含量的X90高强度管线钢进行了显微组织分析,探讨了其显微组织与力学性能关系。结果表明:X90管线钢的显微组织为铁素体(F)+粒状贝氏体(GB),组织中较高的F含量会降低钢板强度;大角度晶界比率较高及有效晶粒尺寸较小时,钢板会获得较好的冲击性能;较高的全厚度方向组织均匀性和细小的铁素体晶粒尺寸会提高低温区间管线钢的落锤撕裂剪切面积,保证其良好的落锤性能。

Microstructure of X90 high strength pipeline steel with low alloy elements was analyzed by SEM and EBSD,and the relation between the microstructure and mechanical properties was investigated. The results show that microstructure of the X90 pipeline steel is composed of ferrite and granular bainite,and the strength decreases with high ferrite content; It is found that with high fraction of the high angle grain boundary and small effective grain size,the plate gets good impact toughness; The shear areas of DWTT at low temperature increase with the good microstructure uniformity in thickness direction of the plate and small ferrite grain size,so the good DWTT property can be guaranteed.