690合金平衡相析出规律的热力学数值模拟

Thermodynamic Simulation of Precipitating Behaivour of Equilibrium Phases

摘要:

690合金中的相析出规律直接影响着其晶界应力腐蚀抗力。应用Thermo-Calc软件模拟计算了690合金的成分变化和热处理温度对平衡相析出规律的影响。结果表明：C含量明显影响M23C6的析出规律，而对γ′和α-Cr相的影响较小；Cr含量对M23C6、γ′和α-Cr相的析出规律都有明显影响；Fe含量对相析出规律影响很小。由此得出结论：合金固溶温度应在1050 ℃以上，等温热处理温度应在700 ℃以上

关键词:690合金;Thermo-Calc软件;平衡相;固溶处理;等温热处理

Abstract:

The precipitating behaviours of phases in alloy 690 affect intergranular corrosion resistance significantly. The effects of chemical composition and heat treatment temperature on equilibrium phases in alloy 690 were simulated with Thermo-Calc software. The content of C is found to affect precipitating behaviour of carbide intensively and those of α-Cr and γ′ phases slightly. The content of Cr affects the precipitating behaviour of these phases markedly. The content of Fe has little effect on the precipitating behaviour of equilibrium phases. Solution treatment temperature should be above 1050 ℃, and thermal treatment temperature should be above 700 ℃

Key words:alloy 690; Thermo-Calc software; equilibrium phase; solution treatment; thermal treatment