Sulfuric acid sulfur dioxide and

Tantalum resists most acids but is attacked by HF and by caustic acids. Unlike glass, however, it is also attacked by fuming sulfuric acid, sulfur dioxide, and chlorosulfonic acid. Due to its very high cost, its use is limited to extremely severe corrosive conditions. Another limitation is that it combines with most gases above 500° C and is susceptible to hydrogen embrittlement. Table 8.28 gives ratings for the resistance of tantalum to a wide spectrum of chemical environments. ... 

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