Investigation on Microstructure and Impact Toughness of Different Zones in Duplex Stainless Steel Welding Joint
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- 作者：Zhiqiang Zhang ; Hongyang Jing ; Lianyong Xu…
- 关键词：duplex stainless steel ; fracture ; microstructure ; toughness ; welding
- 刊名：Journal of Materials Engineering and Performance
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：26
- 期：1
- 页码：134-150
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Characterization and Evaluation of Materials; Tribology, Corrosion and Coatings; Quality Control, Reliability, Safety and Risk; Engineering Design;
- 出版者：Springer US
- ISSN：1544-1024
- 卷排序：26
文摘
This paper investigated on microstructure and impact toughness of different zones in duplex stainless steel welding joint. High-temperature heat-affected zone (HTHAZ) contained coarse ferrite grains and secondary precipitates such as secondary austenite, Cr2N, and sigma. Intergranular secondary austenite was prone to precipitation in low-temperature heat-affected zone (LTHAZ). Both in weld metal (WM) and in HTHAZ, the austenite consisted of different primary and secondary austenite. The ferrite grains in base metal (BM) presented typical rolling texture, while the austenite grains showed random orientation. Both in the HTHAZ and in the LTHAZ, the ferrite grains maintained same texture as the ferrite in the BM. The secondary austenite had higher Ni but lower Cr and Mo than the primary austenite. Furthermore, the WM exhibited the highest toughness because of sufficient ductile austenite and unapparent ferrite texture. The HTHAZ had the lowest toughness because of insufficient austenite formation in addition to brittle sigma and Cr2N precipitation. The LTHAZ toughness was higher than the BM due to secondary austenite precipitation. In addition, the WM fracture was dominated by the dimple, while the cleavage was main fracture mode of the HTHAZ. Both BM and LTHAZ exhibited a mixed fracture mode of the dimple and quasi-cleavage.