Impact Toughness of Heat-Affected Zones of 11Cr Heat-Resistant Steels
来源期刊：Acta Metallurgica Sinica2020年第6期
论文作者：Yongkui Li Jianxin Lou Hongtao Ju Li Lin
文章页码：821 - 827
摘 要：Aiming at the requirements of structural steel in Gen-IV nuclear reactor, the high-chromium martensitic heat-resistant steels containing 10–12% chromium were developed. The toughness of heat-affected zones（HAZs） is one of the important factors for evaluating the weldability of steels. In this paper, the simulated HAZs were fabricated using tempered SIMP steels. The effects of microstructures on the impact toughness of materials were analyzed using Vickers hardness tester, optical microscope, transmission electron microscope. Experimental results demonstrated that the HAZs of weldment were poor in toughness, much lower than that of the base metal. However, after experiencing post-weld heat treatment, the toughness of the HAZs increased greatly. The toughness became better in terms of CG-HAZ, FG-HAZ and IC-HAZ for the two steels, regardless of as-welded or after PWHT. Compared with SIMP7 steel, chemical compositions, such as C, Si, Mn and Cr, were adjusted to a lower content; the toughness of base metal and simulated HAZs was better in the case of SIMP11. The conjunct roles of dislocation density and carbon contents retained in the martensite led to poor impact toughness of the aswelded HAZs, because dislocations and carbon atoms affected the inner stresses within lattices.
Yongkui Li1，Jianxin Lou1，Hongtao Ju1，Li Lin2
1. College of Mechanical Engineering,Shenyang University2. School of Materials Science and Engineering,Shenyang University of Technology
摘 要：Aiming at the requirements of structural steel in Gen-IV nuclear reactor, the high-chromium martensitic heat-resistant steels containing 10–12% chromium were developed. The toughness of heat-affected zones（HAZs） is one of the important factors for evaluating the weldability of steels. In this paper, the simulated HAZs were fabricated using tempered SIMP steels. The effects of microstructures on the impact toughness of materials were analyzed using Vickers hardness tester, optical microscope, transmission electron microscope. Experimental results demonstrated that the HAZs of weldment were poor in toughness, much lower than that of the base metal. However, after experiencing post-weld heat treatment, the toughness of the HAZs increased greatly. The toughness became better in terms of CG-HAZ, FG-HAZ and IC-HAZ for the two steels, regardless of as-welded or after PWHT. Compared with SIMP7 steel, chemical compositions, such as C, Si, Mn and Cr, were adjusted to a lower content; the toughness of base metal and simulated HAZs was better in the case of SIMP11. The conjunct roles of dislocation density and carbon contents retained in the martensite led to poor impact toughness of the aswelded HAZs, because dislocations and carbon atoms affected the inner stresses within lattices.
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