L245NB钢的低温力学性能

Mechanical properties of L245NB steel at low temperature

对L245NB钢从室温到-132℃范围内的低温力学性能进行了检测。结果表明,随温度的下降,钢的屈服强度、抗拉强度及屈强比总体趋向增大,伸长率和断面收缩率降低。深冷处理对L245NB钢的力学性能没有明显影响。从冲击试验的断口宏观形貌以及断口微观特点判断,L245NB钢发生脆化的温度范围为-65^-70℃。

Mechanical properties of L245NB steel were investigated at the temperature range from room temperature to -132℃.The results show that with the temperature decreasing , the yield strength , tensile strength and yield strength ratio of L 245 NB steel tends to increase , the elongation and reduction of area decrease .Cryogenic treatment has no obvious effect on the mechanical properties of L 245NB steel.From the results of impact test and observation of macro and micro morphology of the fracture , the ductile-brittle transition temperature of L 245 NB steel is determined as 65-70 ℃below zero .