时效工艺对AerMet100钢强韧性能的影响

Effect of Aging Process on Strength and Toughness of AerMet100 Steel

采用正常时效、预时效+正常时效、双时效等多种时效工艺对热锻后的Aer Met100钢进行热处理,研究时效工艺对Aer Met100钢回火组织及力学性能的影响。结果表明:正常时效处理后Aer Met100钢的抗拉强度较高(1978 MPa),但是冲击韧性较低(冲击功74J);双时效处理后冲击韧性较高(冲击功102J),但是抗拉强度较低(1662 MPa);经过预时效+正常时效(510℃×30 min,+482℃×5 h)处理得到优良的强韧性能,其抗拉强度为1946 MPa,冲击功为104 J。强韧性提高的原因是:510℃预时效促进了C原子扩散,提高了膜状逆转奥氏体含量及其稳定性,有利于韧性的改善;同时,预时效保温时间短(≤30 min),析出相M2C未与基体脱离共格关系,析出的强化作用提高了强度。

The effect of aging processes on the tempered microstructure and mechanical properties of the forged AerMetl00 steel was investigated, while the named processes include normal aging, pre-ag- ing ＋ normal aging and double aging etc. The results show that high tensile strength （1978 MPa） with low impact toughness （Ak=74J） can be obtained by the normal aging process; higher impact toughness （impact energy 102 J） can be obtained by double aging process, but tensile strength is lower （1662 MPa）; however, excellent strength and toughness （σb=1946 MPa; AK=104 J） can be obtained by pre aging ＋ nor- mal aging （510℃ ×30 min, OQ＋482℃×5 h, AC） process. The improvment of strength and toughness can be attribute to that the 510~C pre aging could promote the C atom diffusion, therewith increased the amount and the stability of the flim-like reversed austenite; besides enable the M2C precipitate to maintain a good lattice relationship with the matrix induced by the short time （≤30 min） pre aging, therefore the precipitation strengthening effect was enhanced.