(中國航發(fā)沈陽發(fā)動(dòng)機(jī)研究所，沈陽 110015)
摘 要: 鎳基高溫合金DD5、DD10和DSM11在涂覆10%NaCl+90%Na2SO4(質(zhì)量分?jǐn)?shù))混合鹽膜后進(jìn)行(850 ℃，200 h)熱腐蝕實(shí)驗(yàn)，并利用掃描電子顯微鏡(SEM)、能譜儀(EDS)和X射線衍射儀(XRD)等分析手段，對(duì)腐蝕200 h后的合金進(jìn)行熱腐蝕行為對(duì)比分析。結(jié)果表明：DD10和DSM11合金成分中含有較高含量的Cr和Ti，在表面易生成保護(hù)性Cr2O3和TiO2氧化膜，氧化膜遇到熔鹽中的O2-會(huì)優(yōu)先在表面發(fā)生溶解，保證內(nèi)部Al2O3氧化膜的穩(wěn)定生長，進(jìn)一步抑制熱腐蝕反應(yīng)的進(jìn)行，提高合金的抗熱腐蝕性能。DD5合金中Cr和Al含量較少且相差不大，在合金表面形成Cr2O3和Al2O3混合型氧化物，導(dǎo)致內(nèi)部元素的貧化，不易形成連續(xù)致密性氧化膜，基體會(huì)進(jìn)一步遭受到腐蝕。
關(guān)鍵字: 鎳基高溫合金；DD5；DD10；DSM11；熱腐蝕；氧化膜
（Shenyang Aeroengine Research Institute, Aero Engine Corporation of China, Shenyang 110015, China）
Abstract:The hot corrosion behaviors of Ni-base superalloy DD5, DD10 and DSM11 in the presence of 10%NaCl+90%Na2SO4 (mass fraction) salt film after corrosion at 850 ℃ for 200 h were tested by scanning electron microscopy(SEM), energy disperse spectroscopy(EDS) and X-ray diffraction(XRD). The results show that O2- in molten salt preferentially reacts with the outside Cr2O3 and TiO2 layer at surface of the alloys DD10 and DSM11 owing to the high Cr and Ti contents. DD10 and DSM11 have excellent thermal corrosion resistance, the further corrosion of alloy enable to be inhibited because of stable growth of Al2O3. The outside Cr2O3 and Al2O3 layer at surface of the alloy DD5 owing to the fewer and similar Cr and Al contents can cause the dilution of internal alloy elements. The alloy DD5 cannot form a continuous oxidation film, the base metal will suffer further corrosion.
Key words: Ni-base superalloy; DD5; DD10; DSM11; hot corrosion; oxidation film
