摘要
轴颈堆焊技术是制造620℃超超临界汽轮机的重要技术之一。采用埋弧焊方法在X13CrMoCoVNbNB9-2-1转子钢圆环试验件上堆焊1Cr-0.5Mo材料,进行去应力热处理;测定了距熔合线不同距离处堆焊层的化学成分,测试了拉伸、硬度、冲击、弯曲等性能,分析了焊接接头的金相组织。试验结果表明,随着距熔合线距离的增加,堆焊层中Cr元素的含量呈指数规律降低,在第四层降到1.5%左右;堆焊层的强度和硬度随着距熔合线距离的增加而下降,冲击吸收功则显著提高。焊接接头弯曲性能优良,焊接接头中各区域微观组织正常,具有良好的综合力学性能。本项技术可以应用于620℃汽轮机X13CrMoCoVNbNB9-2-1钢转子的轴颈堆焊。
Rotor journal surfacing procedure is an important technique for manufacturing 620 ℃ USC steam turbine. 1Cr-0. 5Mo filler metal was deposited on a X13CrMoCoVNbNB9-2-1 ring by submerged arc welding process, a post weld heat treatment was done to release residual stress. Chemical compositions of different surfacing layers were measured, and microstructures were analyzed. Tensile strength, hardness, impact toughness and bending properties were also tested. The results show that the chromium content in surfacing layers decreases at exponential rate with the distance from the fusion line and falls to approximately l. 5 % at the fourth layer. The cross section has good microstructures and excellent plasticity. The tensile strength and hardness decrease with the increasing of the distance from the fusion line while the impact toughness improves significantly. The surfacing joint has excellent mechanical properties and this welding procedure can be applied on X13CrMoCoVNbNB9-2-1 rotors for 620 ℃ steam turbines.
出处
《热力透平》
2015年第2期147-150,共4页
Thermal Turbine
基金
国家科技支撑计划资助项目(2012BAA12B04)
