(華中科技大學(xué) 材料成形與模具技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，武漢 430074)
摘 要: 研究激光選區(qū)熔化(Selective laser melting, SLM)制備Inconel 718合金的高溫腐蝕性能，揭示了不同熱處理工藝對(duì)腐蝕性能的影響規(guī)律。利用超景深顯微鏡、XRD、SEM表征了腐蝕后的形貌及產(chǎn)物。結(jié)果表明：SLM態(tài)的高溫腐蝕質(zhì)量損失速率遠(yuǎn)大于熱處理態(tài)的，經(jīng)標(biāo)準(zhǔn)熱處理與均勻化熱處理的合金其高溫耐腐蝕性能與鍛件的相當(dāng)，時(shí)效熱處理合金在經(jīng)過25 h腐蝕后，原始態(tài)熔池邊界消失，元素均勻化程度提高，氧、硫元素?cái)U(kuò)散通道關(guān)閉，抗腐蝕性能提高；經(jīng)過75 h后，合金表面產(chǎn)物包括氧化物和硫化物，各熱處理態(tài)合金表面的氧化物成分沒有發(fā)生變化。重點(diǎn)分析和討論SLM制備Inconel 718 合金的高溫腐蝕機(jī)理，建立了SLM態(tài)Inconel 718 合金的高溫腐蝕過程中元素?cái)U(kuò)散模型。
關(guān)鍵字: 增材制造；激光選區(qū)熔化；Inconel 718；熱處理；高溫腐蝕
（State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:The Inconel 718 was fabricated by Selective Laser Melting (SLM), and its high-temperaturecorrosion behavior under different heat treatment conditions was evaluated. The morphology and corrosion phases were observed by using ultra depth microscope, XRD and SEM. The results show that the heat treatment can effectively reduce high-temperature corrosion mass loss rate of this alloy. After standard heat treatment and homogenization heat treatment, the high-temperature corrosion resistance of this alloy is comparable with forgings. The corrosion resistance of samples with direct aging treatment increases after 25 h corrosion test, which can be attributed to the disappearance of the melt pool boundary and the improved homogeneity of solute elements. As a result, the corrosion resistance of this alloy also isimproved because the diffusion channels for O and S are closed. After 75 h test, the main phases on the alloy surface are two types of oxides and sulfides, and the composition of these phases has not change under different heat treatment conditions. The high-temperature corrosion mechanism of Inconel 718 alloy prepared by SLM was analyzed and discussed, and the elements diffusion model of Inconel 718 alloy in SLM state was established.
Key words: additive manufacturing; SLM; Inconel 718; heat treatment; high-temperature corrosion
