高温软化和轧制对Super304H耐热钢晶粒长大的影响机理  

Effect Mechanism of High Temperature Softening and Rolling on Grain Coarsening of Super304H Heat-resistant Steel

作　　者：吴跃 柴付方卓 王家庆 刘俊建 方文 王万里 杜成超 WU Yue;CHAI Fufangzhuo;WANG Jiaqing;LIU Junjian;FANG Wen;WANG Wanli;DU Chengchao(Datang Boiler Pressure Vessel Inspection Center Co.,Ltd.,Hefei 230088,China;East China Electric Power Test and Research Institute,China Datang Corporation Science and Technology Research Institute Co.,Ltd.,Hefei 230088,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]大唐锅炉压力容器检验中心有限公司,安徽合肥230088 [2]中国大唐集团科学技术研究总院有限公司华东电力试验研究院,安徽合肥230088 [3]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《热加工工艺》2025年第5期96-100,104,共6页Hot Working Technology

基　　金：中国大唐集团科学技术研究院有限公司重点项目(KY-2021-03);国家自然科学基金项目(52205369);江苏省自然科学基金项目(BK20210756);江苏省博士后基金项目(2021K035A)。

摘　　要：细晶Super304H管被广泛应用于超(超)临界机组的过热器和再热器,然而其细晶的形成及控制机理仍较模糊。系统研究了高温软化和轧制变形对Super304H钢晶粒长大行为和纳米级MX相分布的影响。结果表明:高温软化后,MX相部分溶解进入奥氏体基体,在最终固溶处理过程中又以纳米级形态在晶界析出。轧制变形量越大,纳米级MX相越弥散,MX相对晶界迁移的钉扎作用越强,对晶粒长大的抑制作用越明显。当轧制变形量为56%时,在100 min的最终固溶处理后,晶粒尺寸仍控制在20μm以内。未做高温软化的Super304H,最终固溶过程中无纳米级MX相析出,在0~100 min的最终固溶处理后,晶粒尺寸为25~40μm。Fine-grained Super304H tube has been widely used in superheaters and reheaters of ultra(supercritical)units.However,the formation and control mechanism of the fine-grained microstructure are still unclear.The effects of high-temperature softening and rolling deformation on the grain growth behavior and distribution of nanoscale MX phase of Super304H heat-resistant steel were systematically studied.The results show that the MX phase partially dissolves into the austenite matrix after high-temperature softening.During the final solution treatment,the MX phase precipitates in nanoscale form.The bigger the rolling deformation is,the more dispersive the nanoscale MX phase is,the stronger the pinning effect of MX on grain boundary migration is,the more obvious the depressing effect on grain growth is.When the rolling deformation is 56%,the grain size is still controlled below 20μm after final solution treatment for 100 min.The Super304H without high-temperature softening does not have nanoscale MX phase precipitation during the final solution treatment,and the gran size is 25-40μm after 0 min to 100 min of final solution treatment process.

关 键 词：奥氏体耐热钢 高温软化 轧制 晶粒尺寸 MX相 

分 类 号：TG161[金属学及工艺—热处理] TG335[金属学及工艺—金属学]