Hastelloy B-3和C-276在盐酸中腐蚀行为的研究
发布时间：2018-07-28 14:00
【摘要】：盐酸法提纯是目前电厂粉煤灰制取Al2O3最高效环保的工艺,介质的工作环境为高温、高浓度盐酸中溶解2%~5%氧化性离子(Fe3+和Cu2+),具有非常苛刻的腐蚀性。Hastelloy B-3和C-276在盐酸等还原性酸中具有良好的耐蚀性能;工业纯钛TA1在含有氧化性离子的盐酸中具有良好的耐蚀性。本文研究热处理制度对Hastelloy B-3和C-276组织力学性能、耐蚀性能的影响,以及两种合金在不同服役环境(盐酸浓度、温度、盐酸+氧化性离子浓度)中的腐蚀行为,并与TA1进行对比,探索环境因素对合金腐蚀的影响规律,为开发满足盐酸法提纯Al2O3耐蚀性要求的合金提供数据支持和理论基础。在1040℃-1200℃区间内,Hastelloy B-3和C-276经固溶处理后,随着固溶温度的上升,拉伸强度逐渐下降,塑性逐渐上升。最佳固溶温度为1150℃。Hastelloy B-3和C-276经1150℃×0.5h固溶处理后,材料中大部分碳化物溶解,残留少量M6C相。材料在盐酸中的耐蚀性能明显增加,腐蚀速率下降。随着盐酸浓度、温度上升,Hastelloy B-3、Hastelloy C-276和TA1腐蚀速率逐渐增加。并且相同介质条件下,腐蚀速率由高到低的顺序为:TA1、Hastelloy C-276、Hastelloy B-3。添加Fe3+后,Hastelloy B-3和C-276腐蚀速率显著增加,伴随严重点腐蚀;TA1腐蚀速率急剧下降,基本接近于零。并且随着Fe3+浓度变化,腐蚀速率基本不变。相同介质条件下,腐蚀速率由高到低的顺序为Hastelloy B-3、Hastelloy C-276、TA1。对Hastelloy B-3和C-276腐蚀速率的影响:铁离子浓度温度盐酸浓度。对TA1腐蚀速率的影响:温度盐酸浓度铁离子浓度。在电化学实验中,随着盐酸浓度、温度上升,Hastelloy B-3、Hastelloy C-276和TA1钝化区域电流密度逐渐增加,钝化膜稳定性减弱。随着氧化性离子(Fe3+和Cu2+)加入,溶液氧化还原电位上升。Hastelloy B-3极化曲线没有钝化区,直接由活化区进入过钝化区域,钝化膜溶解;Hastelloy C-276自腐蚀电位显著上升,但材料的过钝化电位基本不变,钝化区域明显缩短,钝化膜稳定性变差;TA1自腐蚀电位升高,钝化区域电流密度降低,斜率减小。表明Fe3+对TA1能起到缓蚀的作用,并且没有过钝化现象的发生。
[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，
本文编号：2150431
[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，
本文编号：2150431
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