Abstract: A method of forming an article comprising in combination the steps of: constructing in a computer (6) memory a first datafile 60) which is a definition of a three dimensional volume model of an article; executing a computer program (42), which reads the first datafile (60) and performs an algorithm which deconstructs the three dimensional volume model to produce a second datafile (62) comprising a string of sequential relative spatial co-ordinates describing a tool path (90,91) through the three dimensional volume model of the article; operating a multi-axis welding robot (2) to position the welding head (16) relative to the worktable (12) such that the relative movement follows the path (90,91) defined by the second datafile (62). The operation of the welding head (16) also being controlled to deposit a weld bead as it follows at least a part of the path to build up a solid representation of the three dimensional volume model of the article.

Abstract: A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

Abstract: An arc welding method capable of easily varying welding conditions such as welding speed, voltage and electric current. The method comprises the steps of teaching a start point to start varying welding conditions such as welding speed, voltage and electric current and an end point to terminate the variations of welding conditions such as the welding speed, the voltage and the electric current, as well as setting the welding conditions at the start point and the end point for gradually varying the welding conditions such as welding speed, voltage and electric current towards end point. By simply setting positions of the start point and the end point and the welding conditions at these positions, it is possible to gradually vary the welding conditions from the conditions at the start point to the conditions at the end point while a welding torch is moved from start point to the end point, thereby contributing to the simplification of the welding condition varying procedure.

Abstract: There is provided a method of applying a weld overlay to a surface of a wastage susceptible chamber. The basic steps of the method include evaluating the post weld orientation of the surface of the wastage susceptible chamber resulting from the movement of the surface in response to the application of a weld overlay thereon and selecting characteristics of a weld overlay to be applied to the surface of the wastage susceptible chamber based upon the step of evaluating the post weld orientation of the surface of the wastage susceptible chamber. The basic steps of the method also include determining a series of weld torch engagement locations relative to the surface of the wastage susceptible chamber at which a weld torch is to be located for performing thereat welding operations which result in a weld overlay on the surface having characteristics corresponding to the predetermined weld overlay characteristics.