Removal of weld oxides from stainless steel : The efficiency of electrolytical cleaning and laser ablation

Sammanfattning

Currently, chemical pickling is used to remove the weld oxides from the surface of welded stainless steels. The present investigation aims to assess the efficiency of electrolytic cleaning and laser ablation on restoring the corrosion resistance properties. The core study was conducted on MAG-welded (metal active gas welding method) plates of austenitic stainless steels – 316L and 254SMO, and duplex stainless steels – 2101, 2205 and 2507.The corrosion pitting temperature was measured using ASTM G-150 testing for each steel after each cleaning trial. Electrolytic cleaning proved to be as efficient as chemical pickling for the high-alloyed stainless steels. On the other hand, laser ablation was not as successful, probably due to weld oxides still present on the surface after the cleaning trials. Electrolytical cleaning is a promising method that could be used in an industry scale as it can be easily taught and has been developed to be performed on-site. More laser trials should be conducted to accurately conclude on the efficiency of this method as there is still a lack of understanding of the effect of different laser settings on different types of alloys