几种钴基合金在Na2SO4—K2SO4混合盐中高温腐蚀行为

本文对Co-30Cr、Co-30Cr-4Al、Co-25Cr-10Ni-4Al-5Ta-0.5Y3种合金在900℃与Na_2SO_4-K_2SO_4混合盐接触条件下的腐蚀进行了研究。结果表明,内硫化-内氧化是主要的破坏形式。Co-30Cr合金腐蚀程度最严重,富铬的内硫化物深入合金基体很深的部位。Co-30Cr-4Al合金中观察到一层细小的富铝内氧化物,通过35S放射性同位素示踪技术探测到了硫对合金基体的侵入。Co-25Cr-10Ni-4Al-5Ta-0.5Y合金中观察到少量富铝的内氧化物,且同时出现钽的富集。

High Temperature Corrosion Behaviors of Some Cobalt-base Alloy in Na2SO4-K2SO4 Salts Mixture

High temperature corrosion behaviors of alloy Co-30Cr, Co-30Cr-4A1 and Co-25Cr-loNi-4Al-5Ta-0.5Y has been studied at the presence of Na2SO4-K2SO4 salts mixture. The experimental results showed the internal sulfidation-internal oxidation to be the major mode of attack. Much severe attack is found in alloy Co-30Cr, and sulfide rich in Cr developed deep in the alloy matrix. Fine inner oxide precipitates rich in Al is found in alloy Co-30Cr-4Al, and sulfur penetration is detected by S radioisotope method. Little inner oxide precipitates rich in Al is found in alloy associated with Co-25Cr-10Ni-4Al-5Ta-0.5Y.