How to reduce nitrogen content in steel during intermediate frequency induction furnace smelting

How to reduce nitrogen content in steel during intermediate frequency induction furnace smelting

When smelting high chromium steel and ferritic stainless steel, nitrogen is a harmful element and measures should be taken to reduce its content. The main measures are as follows.

(1) Select low nitrogen content charge

Ferrochromium is the main charge with nitrogen, followed by metallic chromium and industrial pure iron. When calculating the ingredients, the charge with low nitrogen content should be selected. Generally, the lower the carbon content of the charge, the higher the nitrogen content.

(2) Formulate a reasonable charging system

Low carbon, because the degree of carbon chromium iron should not be too large, it should be put into the high temperature area of ​​the crucible to speed up melting. The vacuum micro-carbon iron should be added to the molten steel, and it is not allowed to be loaded with the charge. melt.

(3) Increase the amount of bottom slag and improve the covering effect of slag

In order to reduce the absorption of nitrogen by molten steel from the atmosphere, the amount of slag should be increased, the fluidity of the slag should be adjusted, the proportion of fluorite should be appropriately increased, and the amount of lime should be reduced to ensure good coverage of the slag.