GB538570A - Improvements in or relating to butt-welding and butt-welded work - Google Patents

Abstract

538,570. Uniting by fusion. BABCOCK & WILCOX, Ltd., HARRIS, H., and JONES, J. E. Feb. 1, 1940, No. 1951. [Class 83 (iv)] In a method of butt-welding, the metal of the edge, at least at the base of the groove, of a part of non-austenitic alloy steel containing up to 3 per cent of nickel, chromium, tungsten, vanadium or molybdenum, or up to a total of 3 per cent of two or more of these metals, consists of weld deposited metal of the same character and thereafter similar weld metal is deposited in the groove to effect the weld. Cracking of forged or cast work parts and of the weld metal in the vicinity of the base of the joint is thus avoided. In a U-joint between parts 4 both of which are of such non-austenitic alloy steel, the edges 5 are machined and then lips 3 of similar metal are weld deposited thereon. After machining the faces of the groove it is filled in a series of layers with similar weld metal by gas or electric arc welding. In a modification one wall of the joint may be a plane edge and if such part is of mild steel no preliminary weld deposited coating thereon need be applied. In making a V-joint between part of such non-austenitic steel the whole of each surface may be first provided with a weld deposited coating of such alloy steel. The metal of the work, deposited layer and fillings may be of the same chemical composition, particularly in making chemical plant, or the first filling layer may be of mild steel. In making a pressure vessel such as a superheater box or portion of a steam line, the whole of the material may consist of ¢ per cent molybdenum steel. After the welding groove is filled with weld metal, metal may be cut away from the underside of the seam and weld metal deposited from that side.