Abstract: In order to study the normalizing cooling rate and the cooling uniformity of hypoeutectoid steel medium- and thick-walled seamless steel tube with wall thickness ≥30 mm, the water-air circulation cooling model is used for the normalizing structure and performance control of medium- and low-carbon Mn steel medium- and thick-walled seamless tube. Based on analysis on structure and properties of normalized steel tube with fen cooling, water fog forced cooling and water-air circulation cooling, the water-air circulation cooling process-immersing part of the steel pipe body in water and high speed rotating meanwhile, and controlling the depth of immersion, the rotation speed of steel tube and the total cooling time, of medium- and thick-walled pipe, the performance of yield strength ≥500 MPa, -20℃ V-type impact energy≥100 J based on the stable structure of ferrite + pearlite are obtained.

摘要： 研究亚共析钢中厚壁(壁厚≥30 mm)无缝钢管正火冷却速度和同一截面的冷却均匀性,将水-空循环冷却模型用于中碳和低碳Mn钢中厚壁无缝钢管正火组织及性能控制过程。通过分析风冷、水雾强制冷却和水-空循环冷却的钢管正火组织和性能,采用"钢管部分浸入水面+高速旋转"的水-空循环冷却方式,即通过控制浸入深度、钢管旋转速度、冷却总时间,最终获得在铁素体+珠光体稳定组织的基础上,中厚壁钢管屈服强度≥500 MPa、-20 ℃V型冲击功≥100 J的性能。

关键词: 正火, 冷却速度, 水-空循环, 中、低碳Mn钢无缝管,