Effect of welding on brittle fracture of two high tensile steels was investigated with notched C-Bead Tear Test Specimens which were side-beaded with six electrodes ; four low hydrogen high tensile electrodes, one ilmenite-type mild steel electrode and one hard-facing electrode.
The conclusions may be summarized as follows :
(a) The effect of welding was very remarkable in crack initiation, and reduced considerably absorbed energy to maximum load, lateral contraction at root-notch, and nominal tensile strength. With a deposit of low ductility, the reduction was very serious.
(b) However, the effect of welding was hardly observed in crack propagation through base metal.
(c) Some examples were observed in which a ductile heat affected zone of base metal could arrest and change into a ductile fracture the brittle crack which had been propagated through a brittle weld metal.
(d) The nominal strength of notched C-Bead Tear Test Specimen was independent of base metal, but depended on the type of electrodes which were used in bead welding.
(e) Home made low hydrogen electrodes which were tested, showed the same quality with an imported electrode of low hydrogen type, as far as notch sensitivity of welded plates was concerned.
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