エア・カーボンアーク法による自動ガウジング(第2報) : パイプの円周溶接部への適用

概要

論文の詳細を見る
On the bases of the results of a previous fundamental study, circumferential-automatic gouging by air carbon-arc method was applied to the shape modification of root bead in pipe welding by gas-shielded metal-arc method, for preventing incomplete fusion, which was apt to arise between the first layer (root bead) and the second one. Study was made on the gouging device, the shape of bead and gouged groove, the metallurgical effect of gouging on base metal (API 5LX-X46), and the soundness of gouged and welded joints. The main results obtained are as follows : 1) A circumferential gouging device of constant electrode feed type is made on trial, and set up in an automatic welding device for pipe joining. 2) A modification of the root bead shape from convex to slight concave by gouging is achieved, for example, using a hollow type electrode (dia. : outer 8,inner 2 mm). This makes the dangerous and time-consuming grinding work almost unnecessary. 3) Though all position operation is required for circumferential gouging, almost all dross is blown off by compressed air, and an increase in C and Cu contents in the base metal just under the groove bottom is hardly observed under appropriate gouging condition, as in flat position gouging. 4) The heating and cooling cycle in gouging is so rapid that the heat affected zone is very narrow, and it is presumed to contain some martensitic structure from the viewpoints of hardness, microphotograph and CCT diagram. 5) No weld defect due to gouging is observed in gouged-and-welded pipe joints under tensile, bending and X-ray tests, and total welding time is largely saved by gouging compared with the case by grinding.
1984-11-05

エア・カーボンアーク法による自動ガウジング(第2報) : パイプの円周溶接部への適用

スポンサーリンク

概要

著者

関連論文

スポンサーリンク