Silicon deoxidation degree

Silicon deoxidation degree measures how strongly silicon reduces the oxygen content in the melt. It forms stable SiO2 compounds and prevents porosity.

Physical-chemical mechanism of action

Silicon reacts with oxygen in the molten pool to form stable SiO2 complexes. This reduces the free oxygen content and prevents the formation of pores in the weld.

Metallurgical relevance & risks when welding

Too high a degree of silicon deoxidation can lead to embrittlement of the weld, which causes hot cracking and low toughness. Too low a degree, on the other hand, can result in porosity and reduced strength levels.

Workshop practice & instructions

Set the silicon deoxidation degree to approx. 0.2 to 0.4 % for most steel grades. Monitor the melting temperature and the addition of silicon closely. The degree can vary for special steels or under high restraint.

MetallurgieSchweißtechnik