Pukyong National University

PKNU's innovative technology, which broke the stereotype for 70 years, received international recognition.
- Super-TIG new welding technology using C-type welding rod ... Obtain final approval from the International Association of Classification Societies (IACS).

Innovative new welding technology developed by PKNU professor breaking the stereotypes of industry for 70 years is internationally acclaimed.

△ Professor Cho Sang-myung. Ⓒ Photo Lee Sung-jae (PR team)

Super-TIG Welding Co., Ltd. (Yongdang-dong, Nam-gu, Busan), a research institute with the head of Professor Cho Sang-myung (Material system engineering) of PKNU, Welding Procedure Specification (WPS) has received the final approval from the global certification,  Norway-German Certification Society (DNV-GL).

There are five WPSs approved this time, △ 9% Nickel steel butt welds (welding of different plates to each other), △ STS316L butt welding and up welding (application of filler on one side), △ Inconel 625 butt welding and up welding.

In particular, butt weld WPS, which is made of C type filler (Inconel 625) for 9% Nickel steel, is expected to drastically lower the cost of welding LNG fuel propulsion line and land LNG storage tank.

Currently, 9% Nickel steel welding, which is often applied to these offshore plants, uses the most commonly used welding methods (FCAW, SAW) in the shipyard. In this case, cracking problems occurred in the high-temperature cracking test and the bending test, and inexpensive Inconel wire could not be used, so that expensive Hastelloy wires had to be used.

However, Super-TIG welding technology showed high efficiency even when using inexpensive Inconel 625 C type filler rather than expensive. The cost of the welding rod is reduced to half, and the productivity is higher than that of the existing FCAW and SAW, so that the welding cost is significantly lowered.

Professor Cho said, "Applying this Super-TIG welding technology to the 9% Nickel steel LNG tank and its piping-related companies is expected to have a significant advantage for domestic companies in competing with overseas companies in China and Japan." <Pukyong Today>


△ C type welding rod.
 
△ PQ test result (tensile test result) of Super-TIG weld joint using Inconel 625 C-Filler of 9% Nickel steel

△ PQ test result (transverse bending test result) of Super-TIG weld joint using Inconel 625 C-Filler of 9% Nickel steel