Are you saying can I run a commercial welder directly off a HV Battery? Or are you asking if you can use an Industrial Motor Control Inverter as a welder?
It’s possible to use a commercial welder directly off a HV Battery, if the welder first rectifies the input line voltage and then uses some form of PWM higher frequency inverter to step the down and control the voltage/current output. If the welder first steps the voltage down using a 50/60 Hz transformer, it can’t be used.