![\"\"](\"https://smille-ap.com/wp-content/uploads/2019/10/title-347ap1.png\")
![\"\"](\"https://smille-ap.com/wp-content/uploads/2019/10/title-317ap1.png\")
You can remove Post Weld Heat Treatment and all the preparation at Fabrication and Construction for your Fire Heater Revamping Project cutting short your construction without anticipating any Polythionic Acid Stress Corrosion Cracking.
Available on Hydrocracking Units, Hydrotreating Units, Delayed Coker Units and Crude Distillation Units and Vaccum Distillation Units with resistance on Naphthenic Acid Corrosion as well.
✓加氢处理装置
IF YOU ARE CONSIDERING A HEATER UPGRADE AND/OR RETUBING, NSC’S HIGH SENSITIZATION RESISTANCE MATERIAL 347AP WILL LEAD YOU TO SUCCESS WITHOUT CONCERNS ON PTA SCC.
A perfect material for your Hydroprocessing heater upgrade/re-tubing
The material feature of 347AP
POLYTHIONIC ACID STRESS CORROSION CRACKING OCCURS ON SENSITIZED STAINLESS HEATER TUBES IN HYDROPROCESSING UNITS.
- Exposure to oxygen and water during turnaround forms Polythionic Acid and that leads to PTA SCC on sensitized stainless steel, where soda ash washing, nitrogen purge and PWHT is required as a NACE countermeasure.
- Sensitized microstructure will not form on the NSC develoed 347AP material therefore soda ash washing, nitrogen purge and PWHTwill not be required which will enable faster fabrication and construction.
In addition to above, the material features of 347AP are as follows.
- High sensitization resistance with excellent PTA SCC free feature superior to Type347LN, Type347, Type321.
- Excellent weldability better than Type347, Type321 minimizing welding repairs.
- High creep properties equivalent to Type347
- High resistance on Stress Relaxation Cracking better than Type347H and as well as Type304H under the design temperature of Hydroprocessing Units.
347AP is a proprietary grade developed by Nippon Steel.
The Metallurgy
（Move to NSC’s official website）
References for 347AP
| 1 | Stainless Steel World | Saving maintenance costs on a hydro-cracker in a refinery complex using Sumitomo 347AP steel tube | Yuya Matsuda, Satoshi Matsumoto and Hidenori Ogawa, ex-Sumitomo Metal Industries | 2010 |
|---|---|---|---|---|
| 2 | Materials & DESIGN | Alloy for resistance to polythionic acid stress corrosion cracking for hydroprocessing applications | Steven A. Bradley, Mark W. Mucek, Honeywell UOP and Hiroyuki Anada, Takahiro Osuki, Nippon Steel Corp. | 2016.01 |
| 3 | Stainless Steel World Conference & Expo 2017 | Weldability of 347AP with excellent Polythionic Acid Stress Corrosion Cracking resistance without PWHT | T. Osuki、K. Yamada、M. Yoshizawa、S. Matsumoto | 2017 |
| 4 | ASME 2017 Pressure Vessels and Piping Conference | DEVELOPMENT OF FIT-FOR-PURPOSE AUSTENITIC STAINLESS STEELS WITH HIGH POLYTHIONIC ACID STRESS CORROSION RESISTANCE | T. Osuki, H. Okada, S. Matsumoto, M. Seto, M. Sagara and T. Ono, Nippon Steel Corporation | 2017 |
| 5 | Hydrocarbon Processing | Metallurgy solution to prevent polythionic acid stress corrosion cracking in hydroprocessing | R. K. Hoehn, Steven A. Bradley, Mark W. Mucek, Honeywell UOP and Hiroyuki Anada, Takahiro Osuki, Nippon Steel Corp. | 2018 |
| 6 | NACE Material Performance | New Metallurgy : Anti-PTASCC Solutions for all petroleum refineries | Nippon Steel Corporation |
The 347AP Supply-ability
All materials required for Anti-PTA SCC in a Fire Heater and Piping system(i.e. Seamless Tubes and Pipes, Fittings, Flanges and Welding consumables) are ready to supply at all size ranges with a competitive price and lead time. Already supplied and used at several Japanese and North American refineries. Mitsui & Co., Ltd. is the responsible supplier of all 347AP products.
IF YOU ARE CONSIDERING A HEATER UPGRADE FOR FURTHER HIGH TAN CRUDE USAGE, NSC`S NON SENSITIZATION STAINLESS MATERIAL 317AP WILL LEAD YOU TO SUCCESS WITHOUT ONCERNS ON NAC AND PTA SCC
✓Hydroprocessing Unit ✓Delayed Coker
A perfect material for your CDU/VDU heater upgrade
The features of the advanced material 317AP
POLYTHIONIC ACID STRESS CORROSION CRACKING OCCURS ON SENSITIZED STAINLESS HEATER TUBES IN HYDROPROCESSING UNITS.
- Tubes will be sensitized due to ascending metal temperature upon heavy coking on the tubes.
- Exposure to oxygen and water during turnaround forms Polythionic Acid, which leads to PTA SCC on sensitized stainless tubes. Soda ash washing, nitrogen purge and PWHT are recommended mitigation methods by NACE (SP0170-2012).
- Sensitized microstructure will not form on the NSC developed 317AP. Therefore soda ash washing, nitrogen purge and PWHT will not be required In addition to above, the material features of 317AP are as follows.
- Excellent Naphthenic Acid Corrosion resistance comparable to 317L, way better than TP316L,-Ti,-Nb.
- PTA SCC free due to non-sensitizing feature under CDU/VDU operating temperatures (Not susceptible to PTA SCC comparable to Alloy. While 316L, 316Ti, 316Nb are susceptible to PTA SCC)
- NACE mitigation methods such as PWHT, Neutralization and Nitrogen purge are not required (cutting short your construction lead time and cost).
317AP is a proprietary grade developed by Nippon Steel.
The Metallurgy
（Move to NSC’s official website）
References for 347AP
| 1 | Stainless Steel World | Saving maintenance costs on a hydro-cracker in a refinery complex using Sumitomo 347AP steel tube | Yuya Matsuda, Satoshi Matsumoto and Hidenori Ogawa, ex-Sumitomo Metal Industries | 2017 |
|---|---|---|---|---|
| 2 | Materials & DESIGN | Alloy for resistance to polythionic acid stress corrosion cracking for hydroprocessing applications | Steven A. Bradley, Mark W. Mucek, Honeywell UOP and Hiroyuki Anada, Takahiro Osuki, Nippon Steel Corp. | 2017 |
| 3 | Stainless Steel World Conference & Expo 2017 | Weldability of 347AP with excellent Polythionic Acid Stress Corrosion Cracking resistance without PWHT | T. Osuki, K. Yamada, M. Yoshizawa and S. Matsumoto |
The Metallurgy
All materials required for Anti-PTA SCC in a Fire Heater and Piping system(i.e. Seamless Tubes and Pipes, Fittings, Flanges and Welding consumables) are ready to supply at all size ranges with a competitive price and lead time. Already supplied and used at several Japanese and North American refineries. Mitsui & Co., Ltd. is the responsible supplier of all 347AP products.
