The continuous development on equipment and technology, together with the training and the refinement of the processes lead to the great result of successful welding and no defects on the most critical material grades.
Together with the direct cooperation and quality surveillance with base material and welding consumables suppliers the key points of successful welding are:
– Direct supervision in the shop
– Low hydrogen consumables and flux handling
– Preheating and post heating and ISR on restrained welds
– Narrow gap technology ( to reduce deposited material, shrinkages, residual stresses and flaw probability)
The welders are qualified according with the major international Codes (ASME, PED 97/23 etc.) and certified by major Third Parties as Lloyd’s Register, Bureau Veritas, DNV, TUV.
Usual tests on CrMo family steels are Step Cool test, transition curves, compliance with API 934, Disbonding Test on WOC with ASTM G146 etc.
Experienced processes are in place to control the H2 content on welding consumables, from the supplier, to the storehouse, to the shop floor and the bevel.
– 335 mm thk base metal weld on LTCS
– 370mm. thk base metal on 2,25Cr1Mo
– 75 mm thk base metal on 2,25Cr1Mo0,25v i spessore
– 110 mm. thk base metal on NiSteel
– Weld overlay by Tp 316L, Tp 317, Tp 347, INCONEL625, INCONEL825, SUPERDUPLEX
• Controlled procurement, handling & distribution of welding consumables
• Low hydrogen consumables. Fully knowledge of the hydrogen control in welding, (hydrogen embrittlement, H.I.C., disbonding, creep cracking)
• Pre heating, post heating, DHT, ISR: in accordance with production best practice and major STD recommendation.
• Disbonding totally controlled on W.O.C.
• Step cool test & transition curves per API RP 934 for severe operating conditions (high pressure & temperature)
• Ferrite measurement on W.O.C. ( sigma phase control )
• Interpass temperature monitoring during welding execution.
• Welders performance monitored during production steps
• Narrow Gap technology (in SAW welding processes)
• SMAW, SAW, FCAM, GTAW, TIG, MIG
• Automatic pulsed ARC TIG
• Hot Wire automatic GTAW
• SAW STRIP OVERLAY 30, 60, 90 MM wide
• ESW STRIP OVERLAY 30, 60, 90 MM wide ( high speed technology )
• W.O.C. on internal diameter, starting from 25 mm