焊接热输入对Q1100粗晶热影响区组织和韧性的影响
发布时间：2018-12-13 04:49
【摘要】：通过焊接热模拟试验,模拟不同热输入下Q1100粗晶区的热循环过程。采用示波载荷冲击试验机检测焊接热模拟试样的冲击韧性,结合OM、SEM观察试样的显微组织和断口形貌;采用TEM观察和Lepera腐蚀,研究不同冷速下M-A组元数量、形貌和分布情况,分析不同热输入对粗晶区显微组织特征与冲击韧性的影响规律。研究结果表明,随焊接热输入的增大,粗晶区的组织由板条马氏体转变为板条马氏体+板条贝氏体的混合组织,最终转变为粗大的粒状贝氏体,原始奥氏体晶粒尺寸逐渐增大;-20℃下的冲击韧性呈现先增大后减小的趋势,焊接热输入为14.95 k J/cm时,相互交割的马贝混合组织使Q1100的粗晶区具有最优的韧性。M-A组元的形成和原奥晶粒尺寸的增大是大热输入下造成韧性下降的主要原因。
[Abstract]:The thermal cycling process of Q1100 coarse-grained region under different heat input was simulated by welding thermal simulation test. The impact toughness of the thermal simulated welding samples was tested by oscillographic load impact testing machine, and the microstructure and fracture morphology of the samples were observed by OM,SEM. The quantity, morphology and distribution of M-A components at different cooling rates were investigated by TEM and Lepera. The effect of different heat input on the microstructure and impact toughness of coarse crystal region was analyzed. The results show that with the increase of welding heat input, the structure of coarse grain region changes from lath martensite to mixed structure of lath martensite bainite, finally to coarse granular bainite, and the grain size of original austenite increases gradually. The impact toughness at -20 鈩，
本文编号：2375909
[Abstract]:The thermal cycling process of Q1100 coarse-grained region under different heat input was simulated by welding thermal simulation test. The impact toughness of the thermal simulated welding samples was tested by oscillographic load impact testing machine, and the microstructure and fracture morphology of the samples were observed by OM,SEM. The quantity, morphology and distribution of M-A components at different cooling rates were investigated by TEM and Lepera. The effect of different heat input on the microstructure and impact toughness of coarse crystal region was analyzed. The results show that with the increase of welding heat input, the structure of coarse grain region changes from lath martensite to mixed structure of lath martensite bainite, finally to coarse granular bainite, and the grain size of original austenite increases gradually. The impact toughness at -20 鈩，
本文编号：2375909
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