Phase Transformation and Carbide Precipitation of Functional Gradient Semi-solid 9Cr18 Steel
来源期刊:Acta Metallurgica Sinica2018年第8期
论文作者:Yong-Jin Wang Ren-Bo Song Ren-Feng Song
文章页码:823 - 830
摘 要:The unique phase transformation and carbide evolution in 9Cr18 steel were investigated during semi-solid forming and subsequent heat treatment. The functional gradient thixoforging 9Cr18 component was divided into inner area and edge area. Microstructure evolution was different at each area. After semi-solid cooling, the solid particles in the inner area were retained as meta-austenite. During annealing, M23C6 carbide began to precipitate when temperature reached 700 °C.Martensite transformation occurred when temperature reached 800 °C. The occurrence of M23C6 carbide and martensite structure would be harmful to the mechanical properties of inner area. In the edge area, the liquid underwent eutectic transformation to form bar-shape M7C3 carbide and secondary austenite after semi-solid cooling. The width of bar-shape carbide would decrease during annealing. By controlling the carbide evolution, we could tailor the functional gradient material with required property.
Yong-Jin Wang1,2,Ren-Bo Song1,Ren-Feng Song3
1. School of Materials Science and Engineering, University of Science and Technology Beijing2. Institute of Industrial Science, The University of Tokyo3. Ansteel Mining Engineering Corporation
摘 要:The unique phase transformation and carbide evolution in 9Cr18 steel were investigated during semi-solid forming and subsequent heat treatment. The functional gradient thixoforging 9Cr18 component was divided into inner area and edge area. Microstructure evolution was different at each area. After semi-solid cooling, the solid particles in the inner area were retained as meta-austenite. During annealing, M23C6 carbide began to precipitate when temperature reached 700 °C.Martensite transformation occurred when temperature reached 800 °C. The occurrence of M23C6 carbide and martensite structure would be harmful to the mechanical properties of inner area. In the edge area, the liquid underwent eutectic transformation to form bar-shape M7C3 carbide and secondary austenite after semi-solid cooling. The width of bar-shape carbide would decrease during annealing. By controlling the carbide evolution, we could tailor the functional gradient material with required property.
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