SUPERHIGH STRENGTH CRYOGENIC WELDED JOINTS Russian patent published in 2003 - IPC

FIELD: joints of superhigh strength low-alloy steels. SUBSTANCE: welded joint has small grain body-centered cubic structure including at least almost 50 vol% of self-tempered rack martensite and less than 250 non-metallic inclusions with diameter more than 1000 nm for 1 sq.mm of cut-off surface of said metal of welded joint and containing alloying element in next quantity (mass%): carbon, approximately 0.06 - 0.1; manganese, approximately 1.6 - 2.05; silicon, approximately 0,2 - 0,32; nickel, approximately 1.87 - 6.00; chrome, approximately 0.3 -0.87; molybdenum, approximately 0.4 - 0.56. It is possible to realize welded joints with rupture strength exceeding 900 MPa. EFFECT: superhigh-strength welded joints with metal of welded seam having rupture viscosity and rupture strength suitable for using at cryogenic temperature condition. 12 cl, 2 dwg, 1 tbl