Effect of interpass temperature on the microstructure and mechanical properties of multi-pass weld metal in a 550-MPa-grade offshore engineering steel
- 340 Downloads
The influence of interpass temperature on the microstructure and mechanical properties of multi-pass weld joints (up to 36-mm thickness) by submerged arc welding (SAW) was studied from the perspective of offshore engineering. Optimal mechanical properties were obtained with the interpass temperature of ~130 °C. Decreasing interpass temperature from 130 to 80 °C increases the strength and hardness at the cost of impact toughness of the weld joint due to the formation of hard phases including bainite and martensite. Increasing the interpass temperature from 130 to 250 °C promotes a larger volume fraction of coarse M-A constituents and larger inter-spacing of high-angle boundaries, which, in turn, deteriorates the toughness. In addition, a large amount of M-A constituent necklacing prior austenite grains was observed in the reheated zone of all weld metals and was responsible for the low impact energy of the weld joint.
Keywords (IIW Thesaurus)Offshore engineering steel Interpass temperature Weld metal M-A constituent Toughness Effective grain size
This work is financially supported by the Natural Science Foundation of China (51371001). Thanks to Mr. Min Li from Technology Center, Jinan Iron & Steel Co., Ltd., for the operation of welding experiment. R.D.K. Misra gratefully acknowledges the support of the University of Texas at El Paso.
- 1.Hu L, Wang PJ (2012) Research on production process of high strength and toughness E550 steel plate for offshore platforms. Baosteel Technol 1:36–42Google Scholar
- 6.Li XD, Ma XP, Subramanian SV, Misra RDK, Shang CJ (2015) Structure-property-fracture mechanism correlation in heat-affected zone of X100 ferrite-bainite pipeline steel. Metall Mater Trans E 2:1–11Google Scholar
- 11.Matsuda F, Ikeuchi K, Fukada Y, Horii Y, Okada H, Shiwaku T, Shiga C, Suzuki S (1995) Review of mechanical and metallurgical investigations of martensite-austenite constituent in welded joints in Japan. Trans JWRI 24:1–24Google Scholar
- 13.Evans GM (1995) Microstructure and properties of ferritic steel welds containing Al and Ti. Weld J 74:249–261Google Scholar
- 16.Byun JC, Bang KS, Chang WS, Park CG, Chung WH (2006) Effects of heat input and interpass temperature on the strength and impact toughness of multipass weld metal in 570MPa grade steel. J KWS 24:64–70Google Scholar