摘要
研究了HSLA100钢轧态及时效过程中组织与力学性能的变化。结果表明:HSLA100钢轧态组织为高密度位错的板条贝氏体,板条间分布着少量M-A岛。经450℃时效处理后,大量球状ε-Cu相沉淀析出,此时钢板屈服和抗拉强度最高,而-40℃冲击功最低。在450～720℃时效时,随时效温度升高,高密度板条贝氏体发生回复,ε-Cu相粗化成短棒状,屈服强度连续下降,但在650℃时效时仍达到760 MPa的较高水平;抗拉强度在650℃时达到最低值后小幅上升;-40℃冲击功持续升高至700℃附近达到峰值。钢质纯净度是影响HSLA100钢低温韧性的一个主要因素,虽然通过升高时效温度可在一定程度上提高钢的低温冲击韧度,但增幅有限。
The variation of microstructure and mechanical properties of HSLA100 plates as-rolled and aged were investigated. The results show that the matrix microstructure of HSLA100 steel is lath bainite with high dislocation density and some M-A island among them. Substantial improvement in strength occurs at the expense of impact toughness on aging by 450℃ owing to profuse e-Cu precipitation in the matrix. With the increase of aging temperature between 450℃ and 720℃, the partially recovered matrix and the coarsened ε-Cu precipitates presumably improve the notch toughness at -40℃ considerably, reaching peak values at 700℃ aging, and reducing the yield strength continuously, dropping to 760 MPa at 650℃ aging, and reducing tensile strength considerably, reaching valley value at 650℃ aging The results reveal that the purity of steel is one of major elements on low-temperature flexibility, though notch toughness can be improved considerably by increasing aging temperature.
出处
《热加工工艺》
CSCD
北大核心
2009年第22期148-151,157,共5页
Hot Working Technology
