プロジェクション径のナゲット形成におよぼす影響 : プロジェクション溶接現象についての研究(第 4 報)

概要

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Projection diameter and height are adapted as factors which characterize a shape of a embossed projection. In this report, the effect of projection diameter on nugget formation and growth has been examined, using the various projections with the constant height, embossed on a cold rolling sheet of low carbon steel of 1mm in thickness (SPCC). Shape of nugget formed without explosive splash at initial period of weld time corresponds to the diameter of cold collapsed area of projection and its pressure distribution. The critical current which is the minimum current required to from nugget increases with the diameter of cold collapsed area corresponding to the area of current path. Using the projection with a small diameter, small nugget is initially formed to grow larger, and on the other hand, using the projection with a large diameter, the contact part is heated like a torus at the initial period of weld time. The tensile sheare strength is related to the nugget diameter and the saturated diameter of nugget depends only on the weld current above the critical current as a function of the cold collapsed area and the electrode force. Using thr projection with a small diameter, the depression of embossed projection is difficult to become flat at the initial period of weld time, however, the indentation is more seriously affected by the splash.
社団法人溶接学会の論文
1979-10-05