A salt bath for nitriding steel and cast iron

摘要

A fused salt bath for nitriding steel and cast iron contains potassium and sodium ions and cyanide and cyanate ions, the weight ratio of potassium to sodium being from 1:1 to 1.857:1. A typical composition consists by weight of 38-44% sodium cyanide, 43-47% potassium cyanate, 2-6% sodium carbonate and 10-14% potassium carbonate. A titanium lined crucible is used to hold the fused salt and air or any oxygen containing gas is passed into the bath.