Combining with the repairing demand of GH4169 alloy surface damage, the effect of substrate preheating process on the residual stress, microstructure and tensile property of laser deposition repair (LDR) GH4169 alloy specimen with different substrate thickness were investigated. The results show that, in contrast to repaired specimen without preheating, laser deposition repair GH4169 alloy after the substrate is preheated to 300 ℃, both σxand σyof residual stress are reduced obviously. The Laves phase of the interdendritic in deposition becomes thick, and it presents a granular fragmentation phenomenon. The tensile strength is reduced slightly, but the elongation rate increases above 60%.These indicate that the standard of forging is reached. With the bigger substrate thickness and the smaller deposition thickness, the residual stress and Laves phase of the interdendritic of repaired specimen are decreased, the tensile strength and elongation are improved slightly.%结合GH4169高温合金表面损伤的修复需求,研究基体预热对不同基体厚度的激光沉积修复GH4169高温合金试样残余应力、显微组织、拉伸性能的影响规律.结果表明:与未预热修复试样相比,基体预热300 ℃的GH4169合金激光沉积修复试样的残余应力σx、σy均明显降低,修复区枝晶间析出的Laves相变得粗壮并呈现颗粒状的碎化趋势,抗拉强度略微降低,但断后伸长率提高60%以上,达到锻件标准.基体厚度越大,修复体厚度越小,修复试样的残余应力减小,枝晶间析出的Laves相减少,抗拉强度与断后伸长率均略有增加.
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