Analysis of Welding Defects of Austenitic Stainless Steel Surfacing Layers and Improvement Measures
Author of the article:WANG Longhu, GUO Ning, CHEN Derun, MA Jin
Author's Workplace:Kocel Steel Foundry Co., Ltd., Yinchuan 750021, China
Key Words: corrosion-resistant surfacing layer; transition layer; hot crack; slag inclusion; welding process
Abstract:
Taking the outer cylinder of a nuclear power plant produced by Kocel as an example, when welding an austenitic corrosion-resistant surfacing layer, the surfacing layer area was subjected to nondestructive testing, and the penetration test found that there were signs after welding was completed. Microcracks and slag defects are found after sampling and observation through a microscope. The microcrack defect is due to the deviation of the grain boundary caused by the NbC phase formed at high temperature, and the slag inclusion defect is caused by the material characteristics of austenitic welding consumables. Through “ no preheating, small current, low heat input, layer temperature control ≤150 °C, and narrow swing ” mode combined with on-site verification welding process, the problems have been successfully solved, providing valuable experience for follow-up similar products.