Improvements in assemblies comprising welded joints uniting austenitic and ferritic alloy steel members

摘要

774,967. Welding by fusion. BABCOCK & WILCOX, Ltd. Dec. 8, 1955 [Dec. 9, 1954], No. 35232/55. Class 83 (4). A fusion welded joint between a ferritic alloy steel member 10, Fig. 1, and an austenitic alloy steel member 20 comprises a deposit 31 of stabilized ferritic alloy steel and a deposit 35 of a heat and oxidation resistant metal overlying the ferro-austenitic junction. A backing 15 supports the weld which also includes a deposit 32 of a ferritic alloy steel similar to the member 10. The ferritic member 10 may be a steel containing 2 per cent Cr, 0.5 per cent Mo; 2.25 per cent Cr, I per cent Mo; 5 per cent Cr, 0.5 per cent Mo; 3 per cent Cr, 1 per cent Mo; and the austenitic member 20 may be a steel containing 18 per cent Cr, 8 per cent Ni with or without Cb or Ti; 25 per cent Cr, 12 per cent Ni; 25 per cent Cr, 20 per cent Ni. The stabilized ferritic alloy may be 5 per cent Cr, 0.5 per cent Mo stabilized with Cb. The overlying deposit may be a steel containing 25 per cent Cr, 20 per cent Ni or an alloy containing 77 per cent Ni, 15 per cent Cr or 80 per cent Ni, 20 per cent Cr. As shown in Fig. 2, the stabilized ferritic alloy steel deposit 33 fills the V-shaped joint between the members 10, 20. As shown in Fig. 3, the stabilized ferritic alloy steel deposit 34 is covered and joined to the austenitic member 20 by an austenitic steel, e.g. containing 25 per cent Cr, 20 per cent Ni, or an alloy such as 77 per cent Ni, 15 per cent Cr. Specification 682,936 is referred to.