鋼のフラッシュ溶接現象の研究(第 2 報) : フラッシュ現象の高速度写真による観察

概要

論文の詳細を見る
Flashing phenomena are observed by using high speed motion pictures of 7500 frame/sec, flashing voltage and current being recorded simultaneously by oscillograph. Some typical phenomena are shown in Photo. Nos. 1∿15. Table 1 shows the experimental con-ditions for the photographs. The marks S, A and N beside the individual frame of the photographs show short circuit, arc and no current-flow respectivcly. S and N are judged from the oscillogram and A from the neon lamp sign as shown Fig. 3 (b). Explosive production of many small molten particles is observed when a short circuit breaks and the following arc strikes. The cause of the splashing might be the local high pressure rise due to the striking of arc. The molten globules hanging at the end of the test pieces are blown off by the shock pressure rise. Due to the difference in the relative position of the arc striking point and the hanging molten metal, various types of flashing as shown in the photo. Nos. 8∿15 are observed. The mechanism of the splashing is illustrated in Figs. 15∿19. The electromagnetic force acting on the molten metal bridging between the test pieces causes the metal to move, and results in the flashing of the type shown in photo No. 6 and Fig. 13. The authors presume that the particles in Nos. 12 and 14 frames in photo No. 14 are driven out of the molten metal by rapid pressure rise due to the arc in No. 9 frame. The arc in No. 9 frame vanishes in the next No. 10 frame and consequently the shock pressure rise is presumed to be small. This molten metal has a very high temperature and can splash into many small particles by a comparatively small shock pressure rise because this molten metal is presumed to have very high fluidity. The discontinuous moving of arcing point in frame Nos. 5∿6 of photo No. 5 may be explained if we imagine that a short circuit of very small duration causes the vanishing of the first arc and the breaking of the short circuit results in the second arc. We can see from photos Nos. 1∿3 that the increasing rate of temperature rise is very high and from photo No. 3 that three parallel arcs are produced by breaking the bridging parts one after another in No. 1 frame. It is observed that flashing and surface appearance of test pieces are influenced by arc current and temperature of test piece end, and fine and smoothing flashing and plain surface of test piece end can be obtained by adjusting the secondary no load voltage or inductance of the circuit.
社団法人溶接学会の論文
1971-01-25

鋼のフラッシュ溶接現象の研究(第 2 報) : フラッシュ現象の高速度写真による観察

スポンサーリンク

概要

著者

関連論文

スポンサーリンク