环境温度对地铁转向架用P355NL1钢强韧性的影响

Influence of ambient temperature on strength and toughness of P355NL1 steel for metro bogie

以地铁转向架材料P355NL1钢为研究对象,通过不同温度下的拉伸试验、冲击试验研究了温度对该种钢强度和冲击性能的影响,同时利用Boltzmann函数对试验结果进行拟合,分析得到材料的韧脆转变温度,并对拉伸和冲击断口形貌进进行了观测。结果表明:环境温度对P355NL1钢强韧性有明显影响,随着试验温度的降低,材料的抗拉强度和屈服强度逐渐增强,而冲击吸收能量呈降低趋势;材料的韧脆转变温度(DBTT),按照冲击吸收能量为-62.57℃,按照纤维断面率为-59.96℃;材料具有良好的低温韧性。

Effect of ambient temperature on strength and impact toughness of P355NL1 steel used for subway frame material was studied through tensile test and impact test at different temperatures. The test results are fitted by Boltzmann function and ductile brittle transition temperature of P355NL1 steel was determined,and also morphologies of fractures of tensile and impact were observed. The results show that low temperature has a significant effect on the strength and toughness of P355NL1 steel. With the decrease of test temperature,the tensile strength and the yield strength increase gradually,and the impact absorbed energy decrease. The ductile brittle transition temperature of P355NL1 steel is- 62. 57 ℃ according to the impact absorption energy,but- 59. 96 ℃ according to the fiber section rate. P355NL1 steel has excellent toughness at low temperatures.