This quality is also assured by supervisory institutions, such as TU¨ V
NORD Polska, whose experts increase their qualifications every month through internal and external training related to the granting of certificates to welding
establishments and by supervising numerous construction projects. Another aim of this study was the qualitative (visual tests and macroscopic metallographic tests) and quantitative(shearing, peel, metallographic tests and hardness
measurement) verification of plasma arc spot welding of thin metal sheets made of corrosion resistance X2CrNi12 steel. Due to a lack of precise guidelines on conducting
this procedure, previously made tests on sheets of the same metal, presented in DIN 6700 and EN 15614-12, were followed. Those results met all the strict qualitative and strength recommendations, as may be seen above. At the same time, they do not differ to any extent from those obtained in our welded joints and in some cases even exceed them.