12NiCrMo压力容器钢的高温力学性能

High temperature mechanical properties of 12NiCrMo steel for pressure vessel

为了得到压力容器钢12Ni Cr Mo的高温力学性能数据,采用Gleeble-1500D热模拟试验机在800~1250℃范围内进行高温拉伸试验,得到了其高温抗拉强度及热塑性曲线,同时应用扫描电镜（SEM）对试样断口进行形貌观察和X射线能谱测定,分析不同温度区间断裂机理及钢中合金成分对高温力学性能的影响。结果表明,12Ni Cr Mo钢在800~1250℃范围内,抗拉强度随着温度的升高而降低,塑性较差区出现在1209~1230℃温度范围内,1220℃时由于氧化物沿晶界析出严重,出现以沿晶断裂为主的脆性断口。

High temperature mechanical properties of 12NiCrMo steel for pressure vessel were investigated by means of high temperature tensile test within the temperature of 800-1250 ℃ on Gleeblel500 thermal simulation testing machine. The high temperature tensile strength and the thermal plasticity curves were obtained, and then the fracture mechanism within different temperature and influence of alloying elements in steels were analyzed based on the fracture observation and X-ray energy spectrum with the help of scanning electron microscope （SEM）. The results show that tensile strength of the 12NiCrMo steel decreases with the increase of temperature between 800-1250 ℃ , the poor plasticity zone appears at the temperature of 1209-1230 ℃. At the temperature 1220 ℃, the formation of brittle fracture is mostly intergranular fracture, because the oxide precipitates along the grain boundary heavily.