Abstract: A method of welding metals wherein the size and shape of a weld pool as w as the traversing of the arc from one metal to the other is commanded magnetically by predetermined data, which data is updated by observing and characterizing isotherms in the weld pool, comparing the observed isotherms with a predetermined set of desired isotherms and then updating the command data for optimum performance.

Abstract: A weld metal cooling rate indication system is provided for a welding mace. The welding machine has a torch which is capable of producing a weld bead and has a speed sensor which senses the speed at which the torch travels as selected by an operator. The indication system includes a device for continuously sensing a profile of temperatures along the weld bead, this profile including a predetermined weld temperature. Another device receives the temperature profile and travel speed of the torch information for calculating and producing a signal which represents rate of change of weld temperature at the predetermined weld temperature. A range of acceptable rates of change of weld temperatures at the predetermined weld temperature is provided so that the rate of change of weld temperature at the predetermined weld temperature can be compared with this range.

Abstract: A method of fabricating large cylindrical sections of titanium or other metals for applications such as pressure hulls from cylindrical segments wherein mated segments are capped off and evacuated, atmospheric pressure being used to force the mating surfaces together during diffusion welding.