DUPLEX STAINLESS-STEELS IN THE PULP AND PAPER-INDUSTRY

Case histories are given of several applications of duplex stainless steels in pulp and paper mill services. Both successes and failures are reviewed MacMillan Bloedel experience shows that duplex stainless steels are well suited to a range of applications owing to strength, fatigue, and corrosion resistance properties superior to the commonly used austenitic stainless steels. They have become an almost automatic maintenance replacement after failures of austenitic stainlesses. Examples are given of different levels of evaluation performed before selecting duplex stainless. All failures of duplex stainless steel experienced at MacMillan Bloedel have been due to misapplication rather than fabrication problems. Misapplications are inevitable because in many cases the actual service conditions are unknown. Oftentime is not available for adequate materials testing before material selection must be made The results in service are compared with expectations.