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通过进行650℃高温时效试验,研究了Tempaloy AA-1钢在时效过程中M_(23)C_6合金相的析出与室温力学性能和冲击韧性的关系,并利用扫描电镜和透射电镜对材料在不同时间时效后Tempaloy AA-1的组织结构和室温冲击断口进行观察。结果表明:随着Tempaloy AA-1钢时效时间的增加,逐渐析出M_(23)C_6合金相,并稳定地分布在晶界处。Tempaloy AA-1时效500 h后,由于晶界处M_(23)C_6碳化物强化作用,屈服强度与抗拉强度达到最大值;时效8 000 h后,晶界处M_(23)C_6碳化物颗粒聚集增大,晶界强化作用弱化,Tempaloy AA-1钢的强度略有降低。长期时效后M_(23)C_6型碳化物没有发现其过度团聚,因此,Tempaloy AA-1钢仍具有良好的时效冲击韧性。Tempaloy AA-1时效后具有良好的力学性能和冲击韧性是由于材料在长期高温时效后具有良好的组织稳定性。
Through the aging test at 650 ℃, the relationship between the precipitation of M 23 C 6 alloy phase and the mechanical properties at room temperature and the impact toughness of Tempaloy AA-1 steel were studied. SEM and TEM were used to study the effect of precipitation, The structure of Tempaloy AA-1 after aging and the impact fracture at room temperature were observed. The results show that M_ (23) C_6 phase precipitates gradually with the increase of aging time of Tempaloy AA-1 steel, and is stable at the grain boundary. After 500 h aging, the yield strength and tensile strength reached the maximum due to the strengthening of M_ (23) C_6 carbides at the grain boundary. After aging for 8 000 h, the grain boundary M_ (23) C_6 carbides Aggregation increases, grain boundary strengthening weakening, Tempaloy AA-1 steel strength decreased slightly. Long-term aging M_ (23) C_6 carbide did not find its over-agglomeration, therefore, Tempaloy AA-1 steel still has good aging impact toughness. Tempaloy AA-1 after aging with good mechanical properties and impact toughness is due to the material after long-term high temperature aging with good organizational stability.