主蒸汽管道运行中直管和弯管金属变化特性研究

对12CrMo、10CrMo910和12CrlMoV低合金钢主蒸汽管运行后的直管和弯管金属力学性能、持久强度和微观结构特性进行试验研究。试验结果表明，主蒸汽直管在高温压蒸汽作用下，其金属使用性能的数值指标变化差异较小，两者一般都在5%的变动范围内，且弯管的数值高于直管，证明主蒸汽管不同部位的钢管金属老龄化进程相同。文中对弯管性能数值指标稍高的原因及蒸汽管道运行中弯管部位故障率高于直管等问题作了探讨。

Study on metallic variation properties of straight pipe and elbow of main steam piping after long-time service

e mechanic properties, permanent strength and microstructure properties of straight pipes and elbows of 12CrMo, 10CrMo910 and 12CrlMoV low alloy steel main steam piping after long-time service were tested and studied. The testing results showed that the variation differences of metallic operating performance value indexes of main steam piping straight pipes and elbows under the high temperature and high pressure action were smaller, generally ranging with 5%, and the value indexes of elbows were higher than those of straight pipes. This phenomena proved that the aging process of pipe metal at different positions was same. This paper investigated the cause for higher value indexes of elbow performance and the problems of the fault rate of elbow position being higher than that of straight pipe during the operation of steam pipes.