δ铁素体对12%Cr超超临界转子钢冲击性能的影响

Effect of δ-ferrite on impact properties of 12%Cr rotor steel for ultra-supercritical steam conditions

高中压转子是超超临界火电机组的关键零部件，要求具有很高的高低温冲击性能，材料一般采用高铬（12％Cr）耐热合金钢。该文通过一系列实验，研究了12％Cr转子钢1Cr12W2NiMoVNbN钢组织中δ铁素体对室温冲击性能的影响。结果表明：δ铁素体的存在会严重损害该钢的冲击性能，而奥氏体晶粒尺寸在一定范围内对其冲击性能影响不大；对已经出现的δ铁素体，可以用在900～1150℃温度区间长期保温的方法进行消除。研究结果对科学制定超超临界高中压转子钢热处理工艺具有参考价值。

High and intermediate pressure rotors made from beat-resisting steels containing 12% Cr are a key part of fossil fueled power plants working at ultra-supercritical conditions and should possess excellent impact properties at both high and room temperatures. The effect of δ-ferrite on the impact properties of 1Cr12W2NiMoVNbN rotor steel was studied experimentally. The results show that the δ-ferrite seriously damages the impact properties of the steel, while the austenite grain size within some range does not obviously affect the impact properties. The results also show that the δ-ferrite can be eliminated by heating at 900 - 1050℃.