鉬鋁鍍層對純鐵及310耐熱鋼的高溫硫化腐蝕影響

本研究主要探討純鐵及310耐熱鋼表面濺鍍鉬鋁鍍層(Mo-20at.%Al)，於硫分壓0.1大氣壓，溫度700℃～900℃下的高溫硫化行為。鉬鋁鍍層係以射頻磁控濺鍍法鍍上，鍍膜時基材溫度為200℃，鍍膜厚度約2μm。研究結果顯示含鍍層之純鐵及310耐熱鋼的腐蝕動力學皆遵守拋物線型定律，且硫化速率常數隨著溫度上升而增快，但其硫化速率皆比原材的硫化速率降低1～2個數量級。硫化後含鍍層之純鐵及310耐熱鋼表面皆生成雙層硫化物，其中，含鍍層之純鐵外層為硫化鐵(FeS/Fe(下標 1-x)S)；內層主要是硫化鐵(FeS/Fe(下標 1-x)S)、硫化鉬(MoS2)及少量的硫化鋁(Al2S3)、Fe1.25Mo6S7.7與Al0.55Mo2S4的混合相。含鍍層之310耐熱鋼外層爲硫化鐵(FeS/Fe(下標 1-x)S)、硫化鉻(Cr2S3/Cr3S4)及(Fe,Ni)9S8；而內層則爲複雜的硫化鐵(FeS/Fe(下標 1-x)S)、硫化鉻(Cr2S3/Cr3S4)、硫化鉬(MoS2)及少量的硫化鋁(Al2S3)、Fe1.25Mo6S7.7與Al0.55Mo2S4的混合相。硫化鋁(Al2S3)及Al0.55Mo2S4的生成，有效地降低了硫化腐蝕速率。

關鍵字

高溫硫化； 310耐熱鋼；純鐵；鉬鋁鍍層

並列摘要

High-temperature sulfidation of pure iron and AISI 310 heat-resistant steel coated with a Mo-20at.% Al film was studied over the temperature range of 700～900℃ at 0.1 atm. sulfur vapor. The Mo-Al coating about 2μm in thickness was prepared by the R. F. magnetron sputter deposition at 200℃. The corrosion kinetics followed the parabolic rate law, and the sulfidation rate constants increased with increasing temperature. The sufidation rates were reduced by 1～2 orders of magnitude for both pure iron and 310 heat-resistant steel with coating. The scales formed on pure iron with the coating layer were bilayered in all cases, consisting of an outer layer of mostly iron sulfide (FeS or Fe(subscript 1-x)S) and an inner complex scale of FeS, Fe(subscript 1-x)S, MoS2, and minor Al2S3, Fe1.25Mo6S7.7, Al0.55Mo2S4, while the scales formed on 310 heat-resistant steel with the coating layer consisted of an outer layer of iron sulfide (FeS or Fe(subscript 1-x)S), Cr2S3/Cr3S4 and minor (Fe,Ni)9S8 and an inner complex scale of FeS, Fe(subscript 1-x)S, MoS2, Cr2S3/Cr3S4, and minor Al2S3, Fe1.25Mo6S7.7, Al0.55Mo2S4. The formation of Al2S3 and Al0.55Mo2S4 is responsible for the reduction of the corrosion rates.

並列關鍵字

sulfidation ； 310 heat-resistant steel ； pure iron ； mo-al coating

國際替代計量

鉬鋁鍍層對純鐵及310耐熱鋼的高溫硫化腐蝕影響

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