(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用鋼彈群釜溶出裝置進(jìn)行高溫腐蝕實(shí)驗(yàn)，結(jié)合SEM和XRD等分析技術(shù)，研究S2-對(duì)低合金鋼在高溫鋁酸鈉溶液中腐蝕行為的影響。采用極化曲線法分析S2-加速低合金鋼腐蝕的原因。結(jié)果表明：在高溫條件下，隨著S2-和堿濃度的升高，低合金鋼具有很高的腐蝕速率，而隨著氧化鋁濃度的升高，腐蝕速率減小。表面腐蝕產(chǎn)物主要成分為Fe3O4，其結(jié)構(gòu)疏松，在攪拌條件下易于從表面脫落。低溫極化研究表明，S2-加速腐蝕原因是在金屬表面形成結(jié)構(gòu)不穩(wěn)定的鐵硫化物，當(dāng)該硫化物被氧化成具有較穩(wěn)定結(jié)構(gòu)的氧化物時(shí)，鐵的腐蝕得到抑制。
關(guān)鍵字: 低合金鋼；S2-；鋁酸鈉溶液；高溫腐蝕；極化曲線
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The effect of S2- on the corrosion behaviors of low alloy steel in high temperature sodium aluminate was investigated by high temperature corrosion test conducted in steel bombs and analysis technologies of SEM and XRD. Polarization curve method was used to examine the origins of the corrosion acceleration. The results indicate that low alloy steel exhibits high corrosion rate as the concentrations of sulfide and hydroxide increase at high temperature, but the corrosion rate of low allay steel decreases with an increase in the concentration of alumina. The corrosion product mainly consists of Fe3O4, with a porous structure, which tends to fall off the surface easily when the solution is stirred. Polarization studies at lower temperature show that, accelerated corrosion is attributed to the formation of unstable iron sulfide with unprotected structure on the surface of metal, and when the sulfide is oxidized to oxide with stable structure, the corrosion of iron is inhibited.
Key words: low alloy steel; S2- ; sodium aluminate solution; high temperature corrosion; polarization curve
