Welding of nodular cast iron - using electrodes contg. silicon carbide so welds free from martensite or ledeburite are obtd.

摘要

The welding operation is undertaken in the presence of silicon carbide, esp. by using a welding electrode which contains silicon carbide. Alternatively, the welding electrode is provided with a sheath contg. SiC. In conventional welding processes for nodular cast iron, hard structures of martensite and/or ledeburite may be formed in or near the weld, so the iron cannot be machined, and/or contains undesirable internal stress, so that post welding heat treatment is essential. The invention eliminates these problems. A welded zone can be obtd. in which the matrix consists only of ferrite and pearlite, i.e. the weld is ductile.