1 Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China 2 State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology,Lanzhou 730050, Gansu, China 3 Atlantic China Welding Concumables, Inc., Zigong 643000, Sichuan, China
In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents
1 Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China 2 State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology,Lanzhou 730050, Gansu, China 3 Atlantic China Welding Concumables, Inc., Zigong 643000, Sichuan, China
ժҪ Microstructural evolution in weld metals was in-situ observed through utilizing a laser scanning confocal microscope at two cooling rates. The specimens with various nickel contents were adopted for the observation. In the specimen with low fraction of Ni (��2 wt��%), granular bainite microstructure (i��e. broad surface relief) transformation from intragranular nucleation site was in-situ observed, while, lath bainite microstructure originating from grain boundary of austenite was in-situ observed for specimens with high mass percentage of Ni (��4 wt��%). With increasing nickel content, the transformation temperature dropped. The prior austenite grain size was initially depressed and subsequently coarsened dramatically with the addition of Ni. The microstructure difference was ascribed to various nucleation sites and growth direction in the matrix. On account of those observations, not only the chemical component, cooling rate and microstructure were systematically correlated, but also the microstructural evolution was definite.
Abstract��Microstructural evolution in weld metals was in-situ observed through utilizing a laser scanning confocal microscope at two cooling rates. The specimens with various nickel contents were adopted for the observation. In the specimen with low fraction of Ni (��2 wt��%), granular bainite microstructure (i��e. broad surface relief) transformation from intragranular nucleation site was in-situ observed, while, lath bainite microstructure originating from grain boundary of austenite was in-situ observed for specimens with high mass percentage of Ni (��4 wt��%). With increasing nickel content, the transformation temperature dropped. The prior austenite grain size was initially depressed and subsequently coarsened dramatically with the addition of Ni. The microstructure difference was ascribed to various nucleation sites and growth direction in the matrix. On account of those observations, not only the chemical component, cooling rate and microstructure were systematically correlated, but also the microstructural evolution was definite.
Gao-jun Mao,,Rui Cao,,*,Jian-hong Chen,,*,Xi-li Guo,Yong Jiang. In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents[J].Journal of Iron and Steel Research International, 2017, 24(12): 1206-1214.
Gao-jun Mao,,Rui Cao,,*,Jian-hong Chen,,*,Xi-li Guo,Yong Jiang. In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents. , 2017, 24(12): 1206-1214.
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