Page 56 - 机械工程材料2025年第三期

徐晓龙，等：道间温度与焊后热处理冷却速率对P91钢焊缝金属冲击韧性与耐腐蚀性能的影响

Effects of Interpass Temperature and Post-Weld Heat Treatment Cooling Rate on
Impact Toughness and Corrosion Resistance of P91 Steel Weld Metal

XU Xiaolong , LI Wenqing , LIU Zishen , YANG Fei , MAO Xinggui , JIANG Yong 1
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(1. Atlantic China Welding Consumables, INC, Zigong 643000, China; 2. The State Key Laboratory of Advanced Processing
and Recycling of Nonferrous Metals, School of Materials Science and Engineering,
Lanzhou University of Technology, Lanzhou 730050, China)
Abstract: P91 steel was subjected to 8-layer 16-pass submerged arc welding at different interpass temperatures
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(250, 300 ℃), and the weld metal was post-weld heated at 760 ℃ for 2 h at cooling rates of 55 ℃ · h and about 20 ℃ · h
(furnace cooling). The effects of interpass temperature and post-weld heat treatment cooling rate on the impact toughness
and corrosion resistance of weld metal were studied. The results show that when the interpass temperature was 250 ℃,
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with post-weld heat treatment cooling rate increasing from about 20 ℃ · h to 55 ℃ · h , the carbide content and its
aggregation degree at grain boundaries of the weld metal decreased, the impact absorbed energy obviously increased by
about 68%, and its fluctuation degree obviously decreased; the free-corrosion potential increased, and the free-corrosion
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current density decreased. When the post-welding heat treatment cooling rate was about 20 ℃ · h , with the interpass
temperature increasing from 250 ℃ to 300 ℃, the carbide content and its aggregation degree decreased, the impact
absorbed energy slightly increased, and its fluctuation degree slightly decreased; the free-corrosion potential increased,
and the free-corrosion current density decreased. Within the range of test parameters, the interpass temperature and the
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post-weld heat treatment cooling rate of submerged arc welding of P91 steel should be controlled at 250 ℃,55 ℃ · h ,
respectively; at this time the weld metal had the largest impact absorbed energy and free-corrosion potential and the
smallest fluctuation of impact absorbed energy and free-corrosion current density, and the impact toughness and corrosion
resistance were the best.
Key words: P91 heat resistant steel; submerged arc welding; post-weld heat treatment; impact toughness;
carbide; corrosion resistance

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View of EVI Mode in Automotive Material Research & Development and

Promoting Application

MA Mingtu , LU Hongzhou , ZHAO Yan , FENG Yi , WANG Guangyao , LI Bo ,
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YUAN Guo , MIAO Xinlei , MENG Jing 6
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(1. China Automotive Engineering Research Institute Co., Ltd., Chongqing 401121, China; 2. CITIC Metals Co., Ltd.,
Beijing 100004, China; 3. Chongqing Innovation Center of Beijing Institute of Technology, Chongqing 401120, China;
4. Sino-US (Chongqing) Super High Strength Material Research Institute Co., Ltd., Chongqing 401120, China;
5. State Key Laboratory of Steel Rolling Technology and Continuous Rolling Automation, Northeastern University,
Shenyang 110819, China; 6. Ansteel ThyssenKrupp Automotive Steel Co., Ltd., Dalian 116600, China)
Abstract: Early vendor involvement (EVI) mode in the research & development and promoting application
of automotive materials is discussed in detail. The background and connotation of the development of this mode and
the important role in the research & development and application of new materials are introduced. The EVI activities
and characteristics of some well-known companies at home and abroad are introduced in detail, as well as the recent
achievements of TAGAL in the digital body platform and its steel solutions are introduced. The progress of EVI
promotion activities by relevant enterprises is introduced. The role of EVI mode in the application of new materials in
newly developed vehicle models is discussed, and the conditions for enterprises to promote the application of EVI mode
are put forward. Finally, the significance of EVI model to dual-carbon strategy is expounded.
Key words: EVI mode; research & development and application of new material; benchmarking car; concept car
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