{"title":"Characterization of nanoscale precipitates and enhanced mechanical properties of high strength weld metals containing Cu additions after PWHT","authors":"Jiamei Wang, X. Di, Chengning Li, Dong-po Wang","doi":"10.1051/metal/2022007","DOIUrl":null,"url":null,"abstract":"In order to match rapidly development of high strength low alloy steels, the new metal cored wire contained copper was designed. The multi-pass weld metals were obtained by gas metal arc welding. Results show that microstructure of weld metals is bainite with M-A constituents, and there are nano-9RCu precipitates after PWHT. The weld metal as welded achieves 737 MPa of yield strength (YS) and 1097 MPa of ultimate tensile strength (UTS), with an elongation 8%. After PWHT, the YS and UTS are 725 MPa and 968 MPa, respectively, and elongation increases to 16%. The lower dislocations density and reduction of Cu element at solid solution state hence for the decrease of YS. As well, the nano-Cu precipitates and reduction of effective grain size make it increase. The combined effect of these factors makes YS decrease by only 12 MPa after PWHT. Besides, a good impact performance (46.6 J) can be obtained after PWHT, while it is only 27.7 J of weld metals as welded. The improved toughness of weld metals after PWHT is obtained by the contributions of finer effective grain size, soft bainite, and dispersed nano-9RCu precipitation. The nano-Cu precipitates can improve strength without damage to toughness of weld metal after PWHT.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"79 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metallurgical Research & Technology","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1051/metal/2022007","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 2
Abstract
In order to match rapidly development of high strength low alloy steels, the new metal cored wire contained copper was designed. The multi-pass weld metals were obtained by gas metal arc welding. Results show that microstructure of weld metals is bainite with M-A constituents, and there are nano-9RCu precipitates after PWHT. The weld metal as welded achieves 737 MPa of yield strength (YS) and 1097 MPa of ultimate tensile strength (UTS), with an elongation 8%. After PWHT, the YS and UTS are 725 MPa and 968 MPa, respectively, and elongation increases to 16%. The lower dislocations density and reduction of Cu element at solid solution state hence for the decrease of YS. As well, the nano-Cu precipitates and reduction of effective grain size make it increase. The combined effect of these factors makes YS decrease by only 12 MPa after PWHT. Besides, a good impact performance (46.6 J) can be obtained after PWHT, while it is only 27.7 J of weld metals as welded. The improved toughness of weld metals after PWHT is obtained by the contributions of finer effective grain size, soft bainite, and dispersed nano-9RCu precipitation. The nano-Cu precipitates can improve strength without damage to toughness of weld metal after PWHT.
期刊介绍:
Metallurgical Research and Technology (MRT) is a peer-reviewed bi-monthly journal publishing original high-quality research papers in areas ranging from process metallurgy to metal product properties and applications of ferrous and non-ferrous metals and alloys, including light-metals. It covers also the materials involved in the metal processing as ores, refractories and slags.
The journal is listed in the citation index Web of Science and has an Impact Factor.
It is highly concerned by the technological innovation as a support of the metallurgical industry at a time when it has to tackle severe challenges like energy, raw materials, sustainability, environment... Strengthening and enhancing the dialogue between science and industry is at the heart of the scope of MRT. This is why it welcomes manuscripts focusing on industrial practice, as well as basic metallurgical knowledge or review articles.