US EPA

7584530 

Meetings & Symposia 

New duplex stainless steel DP28W™ contributes to safe and reliable operation of urea plant 

Nagashima, E; Ideguchi, Y; Kita, Y; Yamadera, Y 

2004 

Denver, CO 

Safety in Ammonia Plants and Related Facilities Symposium 2004 

45 

13-16 

English 

Toyo Engineering Corporation (TEC) and Sumitomo Metal Ind., Ltd. (SMI) have jointly developed new duplex stainless steel DP28W™ [1] for urea plants. TEC have more than 30 years experience in applying duplex stainless steels to a urea plant since 1970s. The biggest advantage of duplex stainless steel is its excellent passivation property in urea-carbamate solution, which enhances reliability of equipment and enables to reduce injection of passivation air. In the meantime, duplex stainless steel has some weakness in corrosion resistance in the heat affected zone (HAZ), which shows up in long-term operation. Therefore chemical composition, forming process and heat treatment etc. should be well designed for duplex stainless steel DP28W™ was born as the best matching urea plant material based on all the feedbacks from long experience of TEC and SMI. 

Advanced process for Cost and Energy Saving (ACES); High pressure (HP); Sumitomo Metal Ind., Ltd. (SMI); Toyo Engineering Corporation (TEC); Accident prevention; Chemical plants; Heat affected zone; Heat treatment; Passivation; Reliability; Stress corrosion cracking; Titanium; Urea; Weldability; Stainless steel