摘要
利用激光粉末床熔化(laser powder bed melting, LPBF)制造GH3536镍基高温合金,通过研究不同激光功率和扫描速度对缺陷数量的影响,进行工艺参数优化.为了缓解沉积态组织的各向异性,消除残余应力,对LPBF制造合金进行固溶处理,探究不同固溶温度对组织及力学性能影响规律.借助扫描电子显微镜(SEM)和配套的电子背散射仪(EBSD)对试样的显微组织进行观察,并进行力学性能测试.结果表明,随着固溶温度的升高,沉积态熔池轮廓消失,碳化物溶解,小角度晶界数量减少. 1 100℃固溶试样常温拉伸的屈服强度为450 MPa,随着固溶温度的升高,小角度晶界对位错运动的阻碍减弱,屈服强度降低,经过1 220℃固溶,试样屈服强度为315 MPa.1 100℃固溶试样的高温抗拉强度为220 MPa,高温拉伸时碳化物沿晶界析出导致晶界脆化,随着固溶温度的增加,沿晶界分布的碳化物数量减少,抗拉强度逐渐增大.
GH3536 nickel-based superalloy was fabricated by laser powder bed melting(LPBF). The effect of different laser power and scanning speed on the number of defects was studied, and the process parameters were optimized. In order to alleviate the anisotropy of the deposited microstructure and eliminate the residual stress, LPBF alloy was treated with solution heat-treatment, and the effect of solution temperature on microstructure and mechanical properties was investigated. Through the characterization of grain size, carbide distribution and grain boundary type, it was found that with the increase of solution heat-treatment temperature, the deposited microstructure disappeared, carbide dissolved, and the number of small angle grain boundary decreased. According to the mechanical properties test, the tensile yield strength at room temperature of solution heat-treated sample with 1 100 ℃ was 450 MPa. With the increase of solution heat-treatment temperature, the resistance of small angle grain boundary to dislocation movement weakened and the yield strength decreased. The yield strength of 1 220 ℃solution sample was 315 MPa. The high temperature tensile strength of 1 100 ℃ solution sample was 220 MPa, and the carbides precipitated along grain boundaries at high temperature. With the increase of solution heat-treatment temperature,the quantity of carbides distributed along grain boundaries decreased, and the tensile strength increased gradually.
作者
马瑞
刘林川
王亚军
白洁
檀财旺
宋晓国
MA Rui;LIU Linchuan;WANG Yajun;BAI Jie;TAN Caiwang;SONG Xiaoguo(Beijing Power Machinery Research Institute,Beijing,100074,China;Shandong Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology at Weihai,Weihai,264209,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin,150001,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2022年第8期73-79,I0008,共8页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51875129)。
关键词
激光粉末床熔化
镍基合金
热处理
组织演变
力学性能
laser powder bed melting
nickel base alloy
heat treatment
microstructure evolution
mechanical properties
