低Mn高Nb耐酸管线钢热处理工艺研究  

Research on Heat Treatment Process of Low Mn High Nb Sour Resistance Pipeline Steel

作　　者：宋欣[1] 谌铁强[1] 张国栋[1] 王志勇[1] 王根矶[1] 白学军[1] 

机构地区：[1]秦皇岛首秦金属材料有限公司,河北秦皇岛066326

出　　处：《焊管》2014年第11期55-59,63,共6页Welded Pipe and Tube

摘　　要：对高Nb管线钢在500-680℃回火工艺处理后的性能与组织进行了研究。试验结果表明,与轧态相比,600℃回火后,材料力学性能达到最优值,其屈服强度提高105-130 MPa,抗拉强度提高50-70 MPa;韧性、伸长率变化较小;回火前后的组织类型保持不变,仍以针状铁素体为主;随回火温度的升高,铁素体板条逐渐合并,M/A组元和碳化物明显分解,出现准多边形铁素体;600℃回火后,析出物钉扎位错的现象比较明显;细小析出物的增加是强度增加、塑性改善的主要原因。The mechanical properties and microstructure of high Nb pipeline steel after tempering at 500-680 ℃ were studied. The results indicated that the mechanical properties achieved the optimal value after tempering at 600℃, compared with the steel at rolled status. The yield strength was increased by 105-130 MPa and tensile strength was enhanced about 50-70 MPa. The toughness and elongation varied slightly. The microstructure type before and after tempering keep the same, which were mainly acieular ferrite;With tempering temperature increased, the ferrite lath gradually was merged, M/A islands and carbides were obviously decomposed, and polygonal ferrite was evolved. After 600℃ tempering,the pinning dislocation phenomenon was obvious ,and the increase of fine precipitates are the main reason for strength increase and plasticity improvement.

关 键 词：管线钢 热处理 回火 力学性能 组织 析出 

分 类 号：TG142.1[一般工业技术—材料科学与工程]