文献类型：期刊文献

英文题名：Failure analysis of a furnace roller in continuous annealing line after long-term service at high temperatures

作者：Huang, Jibo[1];Wang, Lu[2];Wang, Weize[1];Hu, Doudou[1];Zhang, Kun[1];Wang, Tao[1]

机构：[1]East China Univ Sci & Technol, Minist Educ, Key Lab Pressure Syst & Safety, Shanghai 200237, Peoples R China;[2]Baosteel & NSC Automot Steel Sheets Co Ltd, Shanghai 200941, Peoples R China

年份：2020

卷号：107

外文期刊名：ENGINEERING FAILURE ANALYSIS

收录：;EI(收录号：20194207555617);WOS:【SCI-EXPANDED(收录号:WOS:000496757000016)】；

基金：The authors gratefully appreciate the support of National Natural Science Foundation (No. 51275189), Science and Technology Commission of Shanghai Municipality (Project 16DZ2260604).

语种：英文

外文关键词：Furnace roller; SCH22 austenitic stainless steel; Deformation; Microstructure degradation; sigma-Phase embrittlement

摘要：The rollers used to convey steel strips in a continuous-annealing furnace were deformed after about 12 years of service, resulting in an unevenness of the rolled strips. In this study, failure causes of the furnace rollers were investigated in terms of degradation of microstructure and mechanical properties of the roller material. After a long period of high temperature service, the microstructure of the material has changed significantly. A large number of network-like carbides precipitated at the grain boundaries, and these carbides have been greatly coarsened. It was also found that a great number of sigma-phase have formed on the coarsened carbides, and that the volume fraction of the sigma-phase on the grain boundaries has exceeded 50%. In addition, creep cavities have been found in the grain boundaries. Especially in regions with dense grain boundaries, the cavities formed at the intersection of grain boundaries have been linked into chains, which tend to develop into cracks. The grain boundaries of the furnace roller material after service has been severely embrittled. Both tensile and impact fracture surfaces show brittle intergranular fracture characteristics. Compared to the unused material, the tensile strength and impact toughness of the failed roller decreased significantly due to the deterioration of the microstructure. Because of the degraded mechanical properties, the rollers are prone to deformation under the service loads, thus cannot guarantee the normal production of strip steels. The results of this study provide a reference for evaluating the remaining life of furnace rollers after long-term service at elevated temperatures.