CORROSION OF CARBON AND STAINLESS STEELS IN KRAFT DIGESTERS

摘要

The numerous mechanisms of corrosion and cracking in kraft batch and continuous digesters are reviewed. For carbon steel these include stress corrosion cracking, general corrosion thinning, pitting corrosion, and preferential attack of welds and weld buildup, and erosion-corrosion. For austenitic stainless steels these include general corrosion thinning, pitting corrosion, intergranular attack and stress corrosion cracking. Corrosion protection measures include anodic protection, application of stainless steel weld overlay, and thermal spray coating. Construction of new digesters from duplex stainless steels offers the best opportunity for long corrosion-free and maintenance-free service.