Effect of Trace Element on Microstructure and Fracture Toughness of Weld Metal
来源期刊：Acta Metallurgica Sinica2020年第3期
论文作者：Ke Xu Tao Fang Longfei Zhao Haichao Cui Fenggui Lu
文章页码：425 - 436
摘 要：The microstructure and fracture toughness of weld metal under Ti-free and Ti-containing different fluxes were investigated in this study.It was found that the trace element Ti of flux in submerged arc welding produced significant influence on the fracture toughness.The addition of 60 ppm Ti induced the sharp increase in J0.2 value from 232.78 to 364.08 kJ/m2.Microstructure characterization revealed that a large number of oxide inclusions prompted the nucleation of acicular ferrites and refined grains,which improved the fracture toughness of Ti-containing weld metal greatly.Moreover,the crack propagation path was more tortuous and bifurcated due to the small amount of carbide precipitations along grain boundaries and blocky martensite-austenite islands for Ti-containing weld metal.Meanwhile,the large-angle grain boundaries caused crack deflection and increased the resistance of crack propagation compared to Ti-free weld metal.
Ke Xu，Tao Fang，Longfei Zhao，Haichao Cui，Fenggui Lu
Shanghai Key Laboratory of Materials Laser Processing and Modification,School of Materials Science and Engineering,Shanghai Jiao Tong University
摘 要：The microstructure and fracture toughness of weld metal under Ti-free and Ti-containing different fluxes were investigated in this study.It was found that the trace element Ti of flux in submerged arc welding produced significant influence on the fracture toughness.The addition of 60 ppm Ti induced the sharp increase in J0.2 value from 232.78 to 364.08 kJ/m2.Microstructure characterization revealed that a large number of oxide inclusions prompted the nucleation of acicular ferrites and refined grains,which improved the fracture toughness of Ti-containing weld metal greatly.Moreover,the crack propagation path was more tortuous and bifurcated due to the small amount of carbide precipitations along grain boundaries and blocky martensite-austenite islands for Ti-containing weld metal.Meanwhile,the large-angle grain boundaries caused crack deflection and increased the resistance of crack propagation compared to Ti-free weld metal.
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