Abstract: An austenitic alloy has high strength and corrosion resistance and includes from 27 to 32 weight percent nickel and 24 to 28 weight percent chromium. Up to 2.75 weight percent silicon, 3 weight percent copper and molybdenum and 2 weight percent manganese are included for contributing to the characteristics to the alloy rendering the alloy particularly useful for fabricating oil well tubular products. Only very low components of nitrogen, carbon, phosphorus and sulfur are included.

Abstract: A control for an electron beam welder for maintaining the point of impact of an electron beam 16 on the intended weld line 6 between two weldments 2 and 4 and for monitoring or controlling the beam area wherein there is provided a strip of 8 and 10 material on each side of the weld line 6 emitting radiation predominantly of a specific wave length when impinged by the electromagnetic radiation produced by the electron beam 6, means 22 are provided for generating an output signal proportional to the difference in radiation emitted by the two strips of material 8 and 10 which is available for controlling the transverse positioning of the electron beam as required to maintain the point of impact along the intended weld line 6. Means 24 is provided for generating an output signal proportional to the sum of the radiation emitted by the two strips of material which is available for monitoring or controlling the area of the electron beam.