摘要
炼制了不含铌和含0.60%~0.90%Nb的690镍基合金。采用热模拟试验机测定了无铌和含铌690合金的流变应力曲线,采用扫描电子显微镜等研究了Nb的加入对690镍基合金显微组织和热变形行为的影响。结果表明:在相同的热压缩变形条件下,含铌690合金的变形抗力大于不含铌合金;加入合金中的Nb形成了MC(M为Ti、Nb)碳化物并钉扎晶界,降低了M_(23)C_(6)的析出温度和析出量,使γ’相从Ni_(3) Ti转变为Ni_(3)(Ti、Nb)。为提高含铌690镍基合金的热加工性能,需适当提高热变形温度和减少道次变形量。
690 nickel-base alloys without niobium and with 0.60%~0.90%Nb were molten.The flow stress curves of the niobium-free and niobium-containing 690 alloys were measured by thermal simulation testing machine.The effect of addition of niobium on microstructure and hot deformation behavior of the 690 nickel-base alloy was investigated by scanning electron microscope.The results showed that(a)under the same hot deformation condition,deformation resistance of the niobium-containing 690 alloy was larger than that of the niobium-free alloy;and(b)niobium added into the alloy formed MC-type carbide(M corresponding to Ti and Nb)which locked the grain boundary,and causedγ'phase to transform from Ni_(3)Ti to Ni_(3)(Ti,Nb).In order to improve the hot workability of the 690 nickel-base alloy containing niobium,it is necessary to increase hot deformation temperature and to reduce deformation amount per pass in an appropriate degree.
作者
敖影
徐长征
AO Ying;XU Changzheng(BAOWU Special Metallurgy Co.,Ltd.,Shanghai 200940,China)
出处
《热处理》
CAS
2021年第5期35-38,46,共5页
Heat Treatment
关键词
镍基合金
铌
热变形
显微组织
nickel-base alloys
niobium
hot deformation
microstructure
