AerMet100钢力学性能的回火温度敏感性研究

Tempering temperature sensitivity of mechanical properties for AerMet100 steel

研究了超高强度钢AerMet100在427-510℃范围内回火的力学性能,重点关注了在宇航材料规范AMS6532推荐的482℃附近回火时这一材料力学性能的变化,并从理论上进行了解释。结果表明,AerMet100钢的力学性能对回火温度的敏感性较大,当回火温度由476℃提高到488℃,其抗拉强度从2037 MPa下降到1915 MPa,断裂韧度从115.08 MPa.m1/2升高到145.60 MPa.m1/2。482℃附近温度回火力学性能变化显著的主要原因是基体和M2C中的Cr、Mo比值比其它高Co-Ni超高强度钢高,从而加速了过时效过程,使析出强化相的长大速率加快。

Mechanical properties of ultra-high strength steel AerMet100 tempered at 427-510 ℃ were studied,focusing on temperatures near 482 ℃,the optimum tempering temperature suggested by Aerospace Material Specification 6532.The results show that the mechanical properties of AerMet100 steel have a strong sensitivity to tempering temperature,especially near 482 ℃.With the increasing of temperature from 476 ℃ to 488 ℃,tensile strength of the steel decreases from 2037 MPa to 1915 MPa,and fracture toughness increases from 115.08 MPa·m1/2 to 145.60 MPa·m1/2.The mechanical properties of Aermet100 steel tempered at near 482 ℃ change remarkably attributed to accelerated over-aging process caused by higher Cr/Mo ratio in matrix and M2C of AerMet100 steel than that of other high Co-Ni ultra-high strength steels,which accelerates the growth of precipitates.