Super 304H钢超超临界锅炉管热穿孔内裂分析  

Analysis of Inner Crack of Super 304H Steel Ultra-Supercritical Boiler Tube in Hot Piercing Process

作　　者：李鹏[1] 康喜唐 程逸明[1] 李涛涛 拓雷锋[3] 楚志兵[3] LI Peng;KANG Xitang;CHENG Yiming;LI Taotao;TUO Leifeng;CHU Zhibing(Shanxi Taigang Stainless Steel Co.,Ltd.,Taiyuan 030003,China;Faculty of Materials Science and Engineering,North University of China,Taiyuan 030051,China;Faculty of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]山西太钢不锈钢(股份)有限公司,山西太原030003 [2]中北大学材料科学与工程学院,山西太原030051 [3]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《热加工工艺》2022年第17期155-158,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51305228)。

摘　　要：Super 304H超超临界锅炉管采用热穿孔方法制造,内裂是代表性的缺陷。采用扫描电子显微镜对Super304H热穿孔内裂形成的影响因素进行了分析。结果表明:含内裂纹的Super 304H无缝管相对于无内裂纹的无缝管的轴向晶粒较粗且存在尺寸较大的奥氏体晶粒。晶界大量析出NbC、Nb(C,N)是Super 304H热穿孔开裂的主要原因之一。局部Nb(C,N)沿晶聚集,一方面降低了晶界的结合力,导致材料塑性降低;另一方面减弱了其抑制奥氏体亚晶粒长大的能力。Super 304H ultra-supercritical boiler tube is made by hot piercing method, and internal crack is a representative defect. The influencing factors of Super 304H hot piercing were analyzed by using scanning electron microscope(SEM). The results show that Super 304H seamless tube with internal cracks has coarse axial grains and large austenite grains compared to seamless tube without internal cracks. A large number of precipitation NbC, Nb(C,N) in the grain boundaries is one of the main causes of hot piercing cracking. Local Nb(C,N) aggregates along the grain boundary, on the one hand, it reduces the binding force of the grain boundaries and leads to the decrease of material plasticity;on the other hand, it weakens its ability to inhibit austenite subgrain growth.

关 键 词：Super 304H不锈钢 热穿孔 内裂 晶粒 

分 类 号：TG316.15[金属学及工艺—金属压力加工]