Study on Hardened Layer Depth of Steel Heated by Thermal Plasma Arc

There were three connection methods of thermal plasma arc,which were transferred arc,non-transferred arc and combined arc.The effects of different connection methods of thermal plasma arc on hardening depth of steel were studied.The experimental results show that transferred arc and combined arc have higher heating efficiency and larger hardening depth compared with non-transferred arc.But the arc stability of the combined arc and non-transferred arc with smaller orifice diameter is higher than that of transferred arc,and they are more suitable for the hardening treatment by plasma arc.