基于组织均匀性的690合金管冷轧及退火工艺优化

针对国产690合金成品管晶粒组织均匀性控制差的问题,引入不均匀因子Z评定组织均匀性,设计单、双道次冷轧和退火实验.实验结果表明:690合金荒管经变形量50%的单道次冷轧,在1100℃下保温5 min的中间退火处理后晶粒组织最均匀;荒管经一二道次变形量依次为50%、70%的双道次冷轧,两道冷轧工序之间采用1100℃保温时间5 min的中间退火,最后在1060℃下保温5 min或者1100℃保温3 min进行固溶处理获得的组织均匀性最好.

Optimization design of cold rolling and annealing processes for 690 alloy tubes based on microstructure uniformity

Single and double-pass cold rolling and annealing tests were carried out aiming at the poor control of grain size uniformity for 690 alloy tubes in China.A heterogeneous factor Z was introduced to evaluate the uniformity of microstructures.The results show that the grain size is most homogeneous in 690 alloy pierced billets by single-pass cold rolling with a deformation of 50% and annealing at 1 100 ℃ for a holding time of 5 min.The best uniform grain size distribution can be obtained by the first pass cold rolling with a deformation of 50%,the second pass cold rolling with a deformation of 70%,and annealing at 1 100 ℃ for a holding time of 5 min between the two cold rolled processes,followed by solution heat treatment at 1 060 ℃ for 5 min or 1 100 ℃ for 3 min.