Abstract:The effects of tempering temperature on the microstructure and properties of COST-FB2 rotor steel was investigated by OM,SEM and TEM to adjust the strength and toughness of COST-FB2 steel. The results show that with the increase of tempering temperature,the strength and hardness of the tested steel decreases continuously,while the plasticity and impact energy increase;the total displacement of oscillograph at room temperature increases with the increase of tempering temperature. The high strength and low toughness of the tested steel after tempering at 350 ℃ and 570 ℃ can be improved by tempering at 700 ℃ again. The residual austenite in COST-FB2 rotor steel after quenching can be eliminated by tempering at 570 ℃. There are no M3C in martensitic lath after quenching with oil cooling. There are a large number of needle-like M3C within martensitic lath of the tested steel after tempering at 350 ℃ and 570 ℃. M3C phase disappeared and M23C6 precipitates at prior austenite grain boundary and martensite lath boundary after tempering at 700 ℃. There is aggregation and coarsening of M23C6 at prior austenite grain boundary,and some martensite lath recovered.
殷会芳, 杨钢, 赵吉庆. 回火温度对COST-FB2转子钢析出相与力学性能的影响[J]. 钢铁, 2021, 56(5): 91-97.
YIN Hui-fang, YANG Gang, ZHAO Ji-qing. Tempering temperature effect on precipitation and properties of COST-FB2 rotor steel[J]. Iron and Steel, 2021, 56(5): 91-97.
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