Normally It has a rubber-like hold down foot and a plastic handle. Those would melt at welding temps. Take off the rubber foot and if your weld is far enough away from the clamp, it might do. Best to use a welding clamp.
Although this is a fairly heavy duty clamp it has some rubber parts on it that may begin to melt as the metal parts get hot. This is more suited for use as a woodworkers clamp on a jig for drilling or glue set up.