Influence of the type of surface contamination of cast steel LH14 on the quality of padding welds made by coated electrode

Abstract

Pad welding is one of the most common method to repair the surfaces. It helps to recover areas where corrosive wear occurred. It is also used as a method to restore the original shape of worn parts. In this work pad welding on the face on cylindrical specimens of LH14 cast steel made by coated electrodes were carried. For process two types of electrodes were used – Castolin 6601 for pad welding of cast steel and Castolin Xuper NuceloTec 2222 for welding large components made of stainless steel, cast steel or cast iron. Some surfaces were contaminated before the process and others were welded by wrong technique to occur imperfections in specimens. Than samples were subjected to visual and penetrant testing. After the penetrant testing, the forehead was 1 mm deep planned. This was due to the fact that after regeneration processes excess material is often removed. The second penetrant testing was then performed to demonstrate the presence of possible defects. It was found that the samples pad welded with the electrodes for pad weld- ing have 35% less imperfections than the samples made by electrodes for welding. It has also been shown that surface contamination significantly affects to increase number of imperfections. Some of them were superficial and did not appear after the typical repair method, removing excess material.

Keywords

• pad welding
• covered electrodes
• cast steel
• nondestructive testing