In June, our company have received the first domestic roll of Super 2507 from Nippon Yakin Kogyo Co., Ltd  for Exhaust Gas Cleaning Systems (EGCS).

On July 16, Masanori GOKOU, the manager of Welding Technology Technical Research Center, Dr. Fugao Wei, the General Manager of Technical Research Center, Yu Jianguang, the sales manager from Nippon Yakin Kogyo Co., Ltd visited our company and conducted welding technical guidance.

Super 2507 effectively improves the corrosion resistance of the weld area of the Exhaust Gas Cleaning Systems (EGCS) system, especially compared to the ordinary 2507, Super 2507 has a significant improvement for long-term stress corrosion. The detailed data is as following:

High Corrosion Resistant Welded Steel Pipe Made With NAS74NU and TG329J4L

Super duplex stainless steel NAS74NU (≥42.5) is stable in structure, not easy to precipitate harmful phase, and has good corrosion resistance and welding performance. Welded steel pipes with TG329J4L wire have very high corrosion resistance.

Welded pipe: NAS74NU (ASTM A928 Class 2, UNS S32750)

Inner diameter: 274mm, thickness: 15mm

Welding wire: TG329J4L (ER2594), diameter 2.0, 2.4mm

Welding method: manual GTAW

Heat input: 1.6-2.5kJ/mm

Shielding gas: 98% Ar+2%N2

Chemical Composition of Pipe and Wire (mass%)

*PRE=Cr+3.3Mo+16N

Sectional structure of longitudinal weld of welded pipe 

Joint structure of circumferential joint of welded pipe joint

Corrosion resistance of welded pipe wood and welds ASTM G48 MethodC (CPT)

Welded pipe base material: 70 ° C

Welded pipe longitudinal weld: 65 ° C

Ring seam (welding state): 45 ° C

Ring seam (surface grinding): 55 ° C

(Note: The listed data is the result of the experiment and does not represent the scope of product quality assurance)

Through the guidance of Nippon Yakin, our company has improved the welding capacity in the field of EGCS, and will better provide higher quality pipeline products and welding services for the ship operation industry.