銹皮結構及鹽浴處理對AISI430及410不銹鋼酸洗之影響

Effect of Scale Structure and Molten Salt Treatment on the Pickling of AISI 430 and 410 Stainless Steels

本研究主要探討銹皮結構及鹽浴處理對AISI430及410不銹鋼棒材於硫酸中酸洗效果的影響。並探討熱處理以及N2+10% H2熱處理氣氛對AISI 410不銹鋼銹皮性質的影響以及其酸洗效果的變化。由酸洗之結果顯示，對於AISI 430不銹鋼而言，完軋材（as-rolled）直接施以硫酸酸洗後，可去除其表面之銹皮；但是經過退火熱處理（annealed）後，若不施以鹽浴處理則酸洗效果變差，會殘留大量銹皮。對於AISI 410不銹鋼而言，完軋材直接施以硫酸酸洗則可去除表面之銹皮。至於在CH4或潮濕空氣中退火處理之AISI 410不銹鋼而言，無論是有無施以鹽浴處理，酸洗皆無法有效的去除表面的銹皮。但若將410 SS完軋材在N2＋10% H2氣氛中施以退火處理，則可以得到良好的酸洗效果。

The effects of scale structure and molten salt treatment on the efficiency of pickling of AISI 430 and 410 stainless steels in sulfuric acid were studied. The influence of heat treatment and 10% H2 +N2 annealing atmosphere on the properties of the scales and the corresponding pickling efficiency in sulfuric acid were also investigated. The results show that the scale of the as rolled 430 SS can be easily removed after sulfuric acid pickling, while the scale of annealed 430 SS can not be completely removed unless molten salt treatment is applied. For the as rolled 410 SS the scale can only be removed by sulfuric acid pickling following molten salt treatment. However for 410 SS annealed in CH4 or in moist air atmosphere the thick scale formed can not be removed effectively in sulfuric acid pickling even with molten salt treatment. If annealed in 10% H2 +N2 atmosphere, satisfactory sulfuric acid pickling for 410 SS can be obtained in conjunction with molten salt treatment .