Ni_3Al（B）系金属间化合物在Li_2CO_3－K_2CO_3熔盐中的腐蚀电

ELECTROCHEMICAL CORROSION BEHAVIOR OF Ni_3 Al(B)-BASED INTERMETALLIC COMPOUNDS INLi_2CO_3-K_2CO_3 MOLTEN SALT

研究了Ｎｉ３Ａｌ（Ｂ）系金属间化合物在６５００ＣＬｉ２ＣＯ３－Ｋ２ＣＯ３熔盐中的腐蚀电化学行为，发现阳极极化曲线具有活化－钝化－过钝化特征；（γ＋γ’）双相Ｎｉ３Ａｌ（Ｂ）－Ｃｒ基合金由于有Γ相［Ｎｉ（Ｍ）］存在其极化曲线上出现有类似于Ｎｉ所出现的准钝化区。三种Ｎｉ３Ａｌ（Ｂ）系金属间化合物的钝化电位区间在－２２０～＋２４０ｍＶ（Ａｇ／ＡｇＣｌ）。根据表层（ＸＲＤ）和表面（ＡＥＳ）分析结果，讨论了Ｎｉ３Ａｌ（Ｂ）系金属间化合物在活化－准钝化－钝化－过钝化区的溶解－氧化物形成过程。

he electrochemical corrosion behavior of three intermotallic compounds,i.e.Ni3Al(B),Ni3Al(B)CrZr and Ni3Al(B)-Cr-Mg-RE,in 62 Li2CO3-38K2CO3(mol%)molten salt was studied.It was found thatthe anodic polarization curves of three Ni3Al(B) baSed alloys showed characteristiCS of active -passivetranspaseive stages, while two dual-phase Ni3Al(B)-Cr blloys exhibited an additional prepassiverange,similar to pure nickel, due to the contribution of Ni(M)phase.The potential range of passive statefor the alloys under study was-220￣+240 mV(vs.Ag/AgCl).Based on the results of XRD and AES,thedissolution-oxide formation process at various potential stages was discussed respectively.