Acceptance Criteria for Electroslag Weldments in Bridges.

摘要

The research was conducted to develop acceptance criteria that can be used by highway engineers and transportation officials to assure that electroslag weldments when made by controlled procedures under production conditions are suitable for use in tension members of bridges fabricated from approved structural steels with minimum yield points up to 50ksi (345MPa). A literature search was made and extensive studies were conducted using laboratory specimens of electroslag weldments of the type used in full-size bridge girders. These tests included nondestructive examination,thermal distribution,macro-and micro-examination,residual strain,hardness,chemical,weathering,tension,fatigue-crack growth rate,and a wide variety of fracture toughness. Full-size girders of A36and A588steel with thickness transition joints were fabricated and subjected to fatigue loading followed by impulse loading at low temperatures. The data show that adequate strength,ductility,and notch toughness for AASHTO Zone 1and Zone 2service can be obtained with commercially available filler metals and procedures. Tentative acceptance testing procedures are suggested. The girder fatigue studies cause some concern about the fatigue strength of welded joints with a taper in thickness. Further research is necessary. Impulse tests showed adequate low-temperature notch toughness.