Abstract: The effect of aging at 700 T for 0 ~ 3 000 h on ambient tensile properties of Φ57 mm x 9. 7 mm seamless tube steel S31042 （% : 0.06C, 0. 35Si, 1. 18Mn, 24. 50Cr, 20. 54Ni, 0.40Nb, 0.23N） has been studied. Results show that as aging for 0 - 1 000 h, with increasing aging time the yield strength （R_p0.2 ） and tensile strength （ R_m ） of steel S31042 rapidly increase, but the elongation （A） and reduction of area （Z） of steel quick decrease； as aging for more than 1 000 h, the variation of each property index is tending slow； with increasing aging time, the morphology of ambient tensile fracture gradually transforms from tough fracture with enriching dimples to brittle intercrystalline fracture ； as aging for 0 ~ 1 000 h, with increasing aging time the amount of Cr₂₃C₆ phase at grain boundary rapidly increases, and as aging time more than 1 000 h, the change of amount of precipitates at grain boundary is not obvious.

Key words: Steel S31042, Aging, Tensile Properties, Fracture, Cr₂₃C₆ Phase

摘要： 研究了700℃0～3 000 h时效对Φ57 mm×9.7 mm S31042无缝钢管(%:0.06C、0.35Si、1.18Mn、24.50Cr、20.54Ni、0.40Nb、0.23N)室温拉伸性能的影响。结果表明,0～1 000 h时效时,随时效时间的增加,S31042钢屈服(R_p0.2)和抗拉强度(R_m)迅速增加,但钢的伸长率(A)和断面收缩率(Z)急剧降低;当时效时间超过1 000 h,各项性能变化趋缓;随时效时间增加,室温拉伸断口由含丰富韧窝的韧性断口逐渐过渡到沿晶脆性断口;0～1000h时效随时效时间增加,晶界处Cr₂₃C₆相迅速增多,超过1 000 h时效,析出相的变化不明显。

关键词: S31042钢, 时效, 拉伸性能, 断口 , Cr₂₃C₆相