發(fā)布時(shí)間：2018-07-28 14:00

【摘要】：鹽酸法提純是目前電廠粉煤灰制取Al2O3最高效環(huán)保的工藝,介質(zhì)的工作環(huán)境為高溫、高濃度鹽酸中溶解2%~5%氧化性離子(Fe3+和Cu2+),具有非�？量痰母g性。Hastelloy B-3和C-276在鹽酸等還原性酸中具有良好的耐蝕性能;工業(yè)純鈦TA1在含有氧化性離子的鹽酸中具有良好的耐蝕性。本文研究熱處理制度對(duì)Hastelloy B-3和C-276組織力學(xué)性能、耐蝕性能的影響,以及兩種合金在不同服役環(huán)境(鹽酸濃度、溫度、鹽酸+氧化性離子濃度)中的腐蝕行為,并與TA1進(jìn)行對(duì)比,探索環(huán)境因素對(duì)合金腐蝕的影響規(guī)律,為開發(fā)滿足鹽酸法提純Al2O3耐蝕性要求的合金提供數(shù)據(jù)支持和理論基礎(chǔ)。在1040℃-1200℃區(qū)間內(nèi),Hastelloy B-3和C-276經(jīng)固溶處理后,隨著固溶溫度的上升,拉伸強(qiáng)度逐漸下降,塑性逐漸上升。最佳固溶溫度為1150℃。Hastelloy B-3和C-276經(jīng)1150℃×0.5h固溶處理后,材料中大部分碳化物溶解,殘留少量M6C相。材料在鹽酸中的耐蝕性能明顯增加,腐蝕速率下降。隨著鹽酸濃度、溫度上升,Hastelloy B-3、Hastelloy C-276和TA1腐蝕速率逐漸增加。并且相同介質(zhì)條件下,腐蝕速率由高到低的順序?yàn)?TA1、Hastelloy C-276、Hastelloy B-3。添加Fe3+后,Hastelloy B-3和C-276腐蝕速率顯著增加,伴隨嚴(yán)重點(diǎn)腐蝕;TA1腐蝕速率急劇下降,基本接近于零。并且隨著Fe3+濃度變化,腐蝕速率基本不變。相同介質(zhì)條件下,腐蝕速率由高到低的順序?yàn)镠astelloy B-3、Hastelloy C-276、TA1。對(duì)Hastelloy B-3和C-276腐蝕速率的影響:鐵離子濃度溫度鹽酸濃度。對(duì)TA1腐蝕速率的影響:溫度鹽酸濃度鐵離子濃度。在電化學(xué)實(shí)驗(yàn)中,隨著鹽酸濃度、溫度上升,Hastelloy B-3、Hastelloy C-276和TA1鈍化區(qū)域電流密度逐漸增加,鈍化膜穩(wěn)定性減弱。隨著氧化性離子(Fe3+和Cu2+)加入,溶液氧化還原電位上升。Hastelloy B-3極化曲線沒有鈍化區(qū),直接由活化區(qū)進(jìn)入過鈍化區(qū)域,鈍化膜溶解;Hastelloy C-276自腐蝕電位顯著上升,但材料的過鈍化電位基本不變,鈍化區(qū)域明顯縮短,鈍化膜穩(wěn)定性變差;TA1自腐蝕電位升高,鈍化區(qū)域電流密度降低,斜率減小。表明Fe3+對(duì)TA1能起到緩蝕的作用,并且沒有過鈍化現(xiàn)象的發(fā)生。
[Abstract]:Hydrochloric acid purification is the most efficient and environmentally friendly process for the preparation of Al2O3 from power plant fly ash. The working environment of the medium is high temperature. The dissolution of 2% oxidized ions (Fe3 and Cu2) in high concentration hydrochloric acid has very harsh corrosion. Hastelloy B-3 and C-276 have good corrosion resistance in hydrochloric acid and so on, while commercial pure titanium TA1 has good corrosion resistance in hydrochloric acid containing oxidizing ions. In this paper, the effects of heat treatment on the microstructure, mechanical properties and corrosion resistance of Hastelloy B-3 and C-276 were studied, and the corrosion behaviors of the two alloys in different service environments (hydrochloric acid concentration, temperature, oxidizing ion concentration of hydrochloric acid) were compared with those of TA1. The effects of environmental factors on the corrosion of Al2O3 alloys were investigated and the data support and theoretical basis were provided for the development of alloys which meet the requirements of corrosion resistance of Al2O3 by hydrochloric acid method. After solution treatment, the tensile strength and plasticity of Hastelloy B-3 and C-276 decreased gradually with the increase of solution temperature in the range of 1040 鈩，

本文編號(hào)：2150431