The physical properties of carbon steel make it a more challenging material.
Keyhole TIG welding carbon steel is more challenging because of the unique metallurgical properties of carbon steel.
Firstly, the surface tension coefficient is lower in carbon steels than in stainless steel, so the weld pool is inherently much less stable.
Secondly the thermal conductivity is higher in carbon steel than stainless steels, therefore, thermal energy will transfer to the root face much faster than stainless steel.
Using the K-TIG Welding System it is possible to open and sustain a stable keyhole TIG weld in mid-range corrosive steels by adjusting the weld parameters to compensate for these properties.