珠光体耐热钢高温时效后基体力学性能的变化

Change in Mechanical Property of Matrix for Pearlitic Heat Resistant Steel after Long-Term Aging at Elevated Temperature

用Larson Miller(P)参数综合考察了珠光体耐热钢12Cr1MoV高温时效后力学性能的变化。研究表明:随着该参数值的增大,基体硬度下降30%,而且α相晶粒内部存在从晶粒中心至晶界附近的硬度梯度。这一硬度梯度是与晶内合金元素的成分梯度相一致的。分析研究认为:高温长时间时效后,12Cr1MoV钢性能的弱化是钢材料各个结构层次演化(退化)的综合效果。

The change in mechanical properties of matrix for pearlitic heat resistant steel 12Cr1MoV after elevated temperature aging has been examined comprehensively, using LarsonMiller parameter (also called as parameter P). It has been found that, the matrix hardnesses is reduced by about 30 % with the increase of parameter P, and there exists a hardness gradient in phase α from grain center to grain boundary, which is in correspondence with the concentration gradient of alloy elements. It can be considered that the degradation of mechanical properties of 12Cr1MoV steel after longterm aging at elevated temperature is the comprehensive result of evolutions in various structural levels in the steel.