碳含量对热等静压FGH4169合金原始颗粒边界与力学性能的影响

Effects of carbon content on the original particle boundary and mechanical properties of HIP FGH4169 alloy

用3种不同碳含量的GH4169合金粉末为原料,采用粉末热等静压+热处理工艺制备碳含量(质量分数,下同)分别为0.026%,0.045%和0.078%的FGH4169合金,研究碳含量对FGH4169合金PPB(prior particle boundary,原始颗粒边界)和力学性能的影响。结果表明,随碳含量从0.026%增加到0.078%,FGH4169合金析出碳化物增多,超过0.078%后,形成PPB;FGH4169合金中碳化物主要为富Ti和Nb的MC型碳化物,但碳含量对合金中碳化物的种类及形貌没有明显影响;在一定碳含量范围内,随碳含量增加,FGH4169合金基体上析出的γ''相数量减少,且碳化物越来越趋向于在原始颗粒边界聚集,导致合金的室温和650℃高温强度和塑性逐渐减小。

Three types of FGH4169 alloy with carbon mass fraction of 0.026%,0.045%and 0.078%were prepared by hot-isostatic pressing(As-HIP)and heat treatment.The effects of carbon content on the original particle boundary(PPB)and mechanical properties of FGH4169 alloy were investigated.The results show that,with the carbon content increases from 0.026%to 0.078%,the precipitated carbide of FGH4169 alloy increases,and when the carbon content exceeds 0.078%,the PPB formed.The carbides in FGH4169 alloy are mainly MC type carbides rich in Ti and Nb,and the carbon content has no obvious effect on the type and morphology of carbides in FGH4169 alloy;Within a certain range of the C content,as the C content increases,the amount ofγ″phase precipitated in the FGH4169 alloy matrix decreases,and the carbides tend to aggregate at the PPB,resulting in the strength and plasticity gradually decreasing under room temperature and 650℃.