X52NS抗硫无缝管线钢管的开发

Development of sulfur-resistance X52NS seamless line pipe

根据API 5L标准要求设计了X52NS管线钢管的化学成分,采用热膨胀相变仪测定了试验钢种的CCT曲线,并采用＂100 t EAF→LF＋VD精炼→圆坯连铸→精密斜轧机组轧制→正火处理＂工艺流程对X52NS管线钢管进行了工业试制。结果表明：当正火温度为920℃,正火冷却速度应为2~5℃/s时,X52NS管线钢管组织主要为铁素体＋珠光体,晶粒度在8.5级以上;力学性能和抗硫化氢腐蚀性能完全满足API 5L标准要求;具有良好的焊接性能和低温冲击性能,韧脆转变温度为-50℃。

Chemical composition of X52 NS steel for seamless line pipe was designed according to the API 5 L standard. The CCT curves of the steel were measured using thermal expansion instrument. Industrial production of X52 NS line pipe was carried out using a process of＂100 t EAF→LF ＋ VD→CCM→accurancy rolling→normalizing＂. The results show that when the normalizing temperature is 920 ℃ and cooling rate is 2-5 ℃/s,the microstructure of X52 NS line pipe consists mainly of ferrite and pearlite,the grain size is finer than Grade 8. 5,the mechanical properties and H2 S resistance performance meet with the requirement of API 5 L standard,the welding performance and low temperature impact toughness are favorable,and the ductile-brittle transition temperature is-50 ℃.