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 flexible extendable backing shield for use with the welding of reactive metals such as titanium. The backing shield provides a means for selectively distributing the inert gas along the length of the shield and then diffusing the inert gas to the root side of the weld to prevent oxidation and embrittlement of the weld root. The backing shield is of modular configuration so that a plurality of the devices can be readily connected together to shield a variety of complex shapes.

Abstract: A flexible trailing shield for providing nonreactive gas shielding to arc lding operations comprises a housing formed of interlocking transverse segments adapted to flexibly cover weld surfaces having varying configurations. The housing has a torch entrance port for slidably receiving a welding torch, a conduit for receiving gas into the housing, a foraminous material to uniformly distribute the gas within the housing, and a pervious structure through which the gas is dispersed over the weld surface.

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.