Underwater Wet Welding for HSLA Steels: Chemical Composition, Defects, Microstructures, and Mechanical Properties

作     者：Wen-Bin Gao Dong-Po Wang Fang-Jie Cheng Cai-Yan Deng Wei Xu 

作者机构：Tianjin Key Laboratory of Advanced Joining TechnologySchool of Materials Science and Engineering Tianjin University Offshore Oil Engineering Co. Ltd 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2015年第28卷第9期

页      面：1097-1108页

核心收录：

学科分类：080503[工学-材料加工工程] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0703[理学-化学] 0811[工学-控制科学与工程] 080201[工学-机械制造及其自动化] 

基　　金：the financial support of marine scientific research project (investigate on the key technology of underwater welding and inspection processes-developing special machines and processes for local dry and wet underwater welding) sponsored by Offshore Oil Engineering Co.  Ltd 

主　　题：Underwater wet welding Electrode High-strength steel Microstructures Mechanicalproperties 

摘      要：The effect of water depth on underwater wet welds was investigated by underwater wet shielded metal-arc welding technique. The microstructures, chemical composition, welding defects, and mechanical properties were studied. The contents of alloying elements decrease, while the oxygen content increases with water depth. Within 55 m depth, the carbon monoxide reaction is controlling the oxygen content which will further control the contents of alloying elements. The columnar microstructures in weld metal obtained at shallow water consist of grain boundary ferrite, side-plate ferrite, and acicular ferrite, while those at depth greater than 11 m exhibit more proeutectoid ferrite due to the loss of alloying elements. Mechanical properties are a strong function of depth owing to the increase in oxidation of alloying elements and porosity. Welds obtained within 11 m show preferable strength, ductility, and toughness. The mechanical properties significantly drop from 11 to 25 m because of the increased porosity and oxidation of alloying elements.