湿式水中溶接における鋼材のインプラント試験

概要

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For the purpose of estimating susceptibility of steels to cold cracking in underwater wet welding, implant weldability tests (Test piece : 8(mm)^φ, 0.5mm (40°, 0.10mmR) helical V-notch) for underwater welds were conducted, while diffusible hydrogen evolved from weld metal was measured according to the method specified in JIS Z 3113-1975. The test welding (Bead welding in flat position) was carried out at a depth of 20cm in fresh water by using a plasma arc as a source of heat. No filler metal was supplied. The results are summarized as follows : 1) The underwater weld just after solidification was estimated to contain diffusible hydrogen of the level of some 9.4ml/100g of weld metal (Collecting medium : Glycerin). 2) For the lower critical stress (σ_<cr>)_<imp> (below which cracking does not lead to complete rupture of the implant) to exceed the yield point σ_Y of the base metal, it was required that cooling time from peak temperature to 100℃, S_(P-100℃), during underwater welding was over [table] 3) At a fixed time of S_(P-100℃), (σ_<cr>)_<imp>'s of steels under water were higher than those in air because of lower hardness in coarse-grained regions of underwater welds.
社団法人溶接学会の論文
1980-08-05