A FABRICATION METHOD OF HIGH NITROGEN-LOW NICKEL DUPLEX STAINLESS STEELS

摘要

The present invention relates to a method for manufacturing high nitrogen-low nickel duplex stainless steel including the following steps of: a parent alloy metal charging phase for charging parent alloy metal into a vacuum melting furnace; a vacuum maintaining phase for maintaining the vacuum status of the vacuum melting furnace; a melting alloy metal phase for melting the parent alloy metal by heating the vacuum melting furnace; a nitrogen contents adjusting phase for injecting nitrogen gas into the vacuum melting furnace; and an ingot forming phase for forming an ingot by tapping the stirred molten alloy from inside the vacuum melting furnace. The nitrogen contents adjusting phase includes a process for injecting nitrogen gas into the vacuum melting furnace. The duration time for nitrogen injection process is about 9-15 minutes. Under a predetermined partial pressure of nitrogen, a desired solubility of the nitrogen can be adjusted.