GH901 alloy is a kind of precipitation hardening Fe-Ni-Cr-based high-temperature alloys, which are age hardened by a metastable fcc phases,γ'[Ni3 (Al, Ti)] . In the steel, traces of aluminum inhibit the transformation ofγ' phase toη-Ni3Ti. Since the alloy microstructure, properties are sensitive to hot working parameters, and special forgings has special requirements for the metal flow lines, improper forging or heat treatment process parameters most likely result in quality problems, such as cracking and defects. In this paper, the formation process of macroscopic crack metallographic structure and SEM results of GH901 stepped shaft were analyzed comprehensively, the reasons for cracking found out, and the improving measures pointed out, so products for stepped shaft could meet the relevant requirements, which provide guidance for the production of a variety of high temperature alloys stepped shaft.%GH901合金是Fe-Ni-Cr基沉淀硬化型变形高温合金,合金以亚稳的面心立方γ′[Ni3(Al,Ti)]相进行时效强化,微量的铝抑制γ′向η-Ni3Ti相转化,由于合金组织、性能对热加工参数比较敏感,以及特殊锻件对金属流线的特殊要求,锻造、热处理工艺等参数选择不当,容易产生锻件裂纹及探伤缺陷等质量问题.本文对GH901台阶轴裂纹的宏观产生过程、微观金相及扫描电镜结果进行综合分析,找到裂纹形成的原因,并通过得出试验结果,提出工艺改进措施,最终生产出合格的台阶轴产品,同时优化后的工艺对多种高温合金台阶轴的生产具有指导意义.
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