DUPLEX STAINLESS-STEELS IN THE PULP AND PAPER-INDUSTRY

Case histories are given of several applications of duplex stainless s teels in pulp and paper mill services. Both successes and failures are reviewed MacMillan Bloedel experience shows that duplex stainless ste els are well suited to a range of applications owing to strength, fati gue, and corrosion resistance properties superior to the commonly used austenitic stainless steels. They have become an almost automatic mai ntenance replacement after failures of austenitic stainlesses. Example s are given of different levels of evaluation performed before selecti ng duplex stainless. All failures of duplex stainless steel experience d at MacMillan Bloedel have been due to misapplication rather than fab rication problems. Misapplications are inevitable because in many case s the actual service conditions are unknown. Oftentime is not availabl e for adequate materials testing before material selection must be mad e The results in service are compared with expectations.