钢管在线加速冷却技术开发

研究了化学成分和生产工艺参数对钢管在线加速冷却后组织、性能的影响.结果表明,材料经过穿孔工序或连轧工序后,为奥氏体完全动态再结晶组织;经过张减工序后,为加工硬化状态的奥氏体组织.采用轧后余热和水气复合冷却方式对钢管外表面加速冷却,可以保证钢管轴向、周向、径向3个方向上的强度和硬度均匀性.采用25MnVN或25MnMoVN之类微合金钢,经过轧后加速冷却,可以不经过调质热处理,生产出性能完全满足要求的N80钢级石油套管.

Development of Online Accelerated-Cooling Process for Seamless Pipes

The effect of chemical composition and process parameters on the microstructure and mechanical properties of steel pipes under accelerated-cooling conditions is investigated.The results show that after the piercing or mandrel milling process,the steel for pipes will become a complete dynamic austenite recrystallization microstructure.After stretching and reducing processes,it will become an austenite structure in the work-hardened state. Cooling steel pipe's surface in a compound cooling way of utilizing residual heat and water vapor may guarantee the pipe'suniformity of strength and hardness in longitudinal,radial and circumferential directions.Microalloyed steels like 25MnVN or 25MnMoVN can be made into N80 grade casing pipes under accelerated-cooling conditions after being rolled,without quenching-tempering treatment.