Study of porosity tendency in the Cr-Ni austenitic weld based on inclusion＇ s characteristic in the droplet

The effect of nonmetallic inclusions in the droplet of the stainless steel covered electrode on the porosity was researched. The result shows that the nonmetallic inclusions in the droplet are spherical,their composition is different from the one of slag and the inclusions have the character of “inner formation”. When the ratio of rutile to ilmenite in the coated material is increased, the droplet becomes coarse, the content of nonmetallic inclusion in the droplet decreases ,and the porosity sensitivity in the weld metal also decreases. When the ratio of fledspar to ilmenite in the coated material is increased, the droplet becomes fine, the content of nonmetallic inclusion in the droplet increases, and the porosity sensitivity in the weld metal increases. When the ratio of Fe2O3 to ilmenite in the coated material is increased, the droplet becomes fine, the content of nonmetallic inclusion decreases, while the porosity sensitivity does not reduce.