| 摘要 |
1402964 Welding by fusion ELEKTROTHERMIT GmbH 20 Feb 1973 [24 Feb 1972] 8363/73 Heading B3R In aluminothermically welding together rails, (1) the ends of rails S are spaced apart a width L=1 to 2 times the rail web thickness A (e.g. A=16 mm.) and surrounded by a prefabricated refractory mould 4 having, adjacent the web and flange, band-shaped internal recesses 5 having a width C and a depth D respectively 2 to 4 and 0À15 to 0À6 times the web thickness A, (2) the rail ends are pre-heated from above by a burner 6 generating a ribbon-shaped flame 7 having a width B=1À5 to 2À5 times the web thickness A, and (3) aluminothermically produced steel is poured into the mould either from above or from one side. The recesses 5 provide for adequate preheating over the whole of the rail ends, and shallow band-shaped weld beads resulting from the recesses are such that excessive accumulation of aluminothermically produced steel, and hence weld cracks, are avoided, that they do not significantly interfere with roller straightening of used rails, and that the use of an oxyacetylene cutter is not impeded. |
