09MnNiDR低温容器钢高温力学性能研究

采用Gleeble-1500热模拟机研究了 09MnNiDR钢的高温力学性能,得到600～1350℃范围内试样的断面收缩率、抗拉强度和应力应变曲线,并结合扫描电镜(SEM)观察断口形貌和FactSage软件进行凝固相分析.结果表明,该钢种的第Ⅰ高温脆性区为液相线温度(tL)到1 350℃,高温塑性区为1 350～950...

Study on high temperature mechanical properties of 09MnNiDR cryogenic vessel steel

igh temperature mechanical properties of 09MnNiDR steel were investigated on Gleeble 1500 thermal simulation testing machine. The percentage of section shrinkage, tensile strength and stress strain curves were obtained within the temperature range of 600-1350℃, and the fracture morphology was analyzed with the help of scanning electron microscope (SEM). Solidification phase transition was calculated by FactSage software. The results show that the high temperature interval of brittleness (Ⅰ) starts from liquidus temperature(tL) to 1350℃, afterwards following with the high temperature interval of plasticity from 1350 to 950℃, and the third area from 950 to 600℃ is the low temperature interval of brittleness(Ⅲ). The high temperature interval of plasticity is related to the austenite phase with great plasticity, while the high temperature tensile strength is low; the reason for the decrease of plasticity in the low temperature interval of brittleness(Ⅲ) is attributed to the γ→α phase transition when temperature lower than 950℃. The observation of fracture morphology showed the high temperature interval of plasticity is transcrystalline rupture and the low temperature interval of brittleness(Ⅲ) is intergranular fracture. Meanwhile the liquid inclusion MnO SiO2 Al2O3 was observed on the fracture morphology of the high temperature interval of plasticity. Based on ternary phase diagram calculation, the melting point of inclusion is less than 1300℃. In order to control the inclusion with low melting, the ration of MnO/SiO2 should be controlled between 1 and 15, while the content of Al2O3 is from 10 mass% to 17 mass%, so as to reduce the risk of internal cracks during continuous casting.