Elektro-thermit Gmbh

Frank Kuster

Michael Steinhorst

Gerhardus Johannes Mulder

Hans Guntermann

Gerhard Skreba

Donald MacRae

The invention relates to a process for the aluminothermic welding of rails, the aluminothermically produced steel being poured into a refractory mold surrounding the rail ends which are to be joined, and alloying additives being contacted with that part of the steel which runs out of the reaction crucible and forms the weld in the rail head region, wherein the alloying with the alloying additives is carried out after the completion of the aluminothermic reaction and separation of the steel from the slag via the diverting plug in the mold, and the overflow in the is closed.

Process for the aluminothermic welding of rails with alloying of the weld metal in the rail head region

In order to reduce the residual stresses which occur in the region of a fusion weld of two rail ends (1,2), in order to reduce, in particular to make uniform, the cooling-down rate and--associated with this--the crystallization process within the solidifying weld material, a casting mold is proposed which is equipped with a system of risers (9) and air vents (10) which are designed symmetrically with respect to a longitudinal center plane (5) and a transverse center plane (3) of the welded joint, the risers (9) and the air vents (10) being physically distributed as a function of geometric parameters of the rail foot (8) and of the weld bead (4), and the cross sections of the air vents (10) being dimensioned as a function of the cross sections of the risers (9). The positioning of the air vents (10) and of the risers (9) according to the invention in conjunction with the cross-sectional dimensioning of the former allows cooling conditions to be set up in which the weld material is effectively prevented from solidification starting on the outside with respect to the rail profile, and in which a considerable reduction in the residual stresses can be achieved, with the cooling process being slowed down overall.

Casting mold for fusion welding of two workpieces

Method for intermediate cast type welding of finely pearlitized rails by pouring steels produced by the Thermit fusion process into a casting mold, which surrounds the two rail ends 13 separated from each other by an intrinsic gap L1, wherein the actual rail gap L1 is increased across the entire rail head width 14 starting on both sides of the rolling surfaces 8 of each rail end 13 in longitudinal -h and vertical -v direction by a dimension of 1/10 to 10/10 of the dimension of the intrinsic rail gap L1 to a dimension of L2.

Method for intermediate cast type welding of finely pearlitized rails

Method for raising rail joint welds lying below the traveling surface on railroad tracks by heating the weld by means of an aluminothermic mixture which solidifies after reacting, wherein a) the aluminothermic mixture (21) is used in an amount measured in kilograms equalling from one fifth to one tenth of the weight per meter of the rail (15) measured in kilograms, wherein a1) 30 to 60% of this amount is used to heat the base (10) of the rail in a length of 150 to 300 mm (as measured symmetrically with reference to the weld in the longitudinal direction) and a2) the rest of the aluminothermic mixture (21) is used in equal proportions to heat both sides of the rail web (18), b) the aluminothermic mixture (21) is ignited, c) remains on the rail (15) after igniting for a period measured in minutes which corresponds to 0.7 to 1.5 times the number of kilograms of the aluminothermic mixture (21), whereupon d) the reacted and compacted mixture is removed from the base (10) and from the web (18) of the rail.

Method for raising welded rail connections lying below the traveling

Aluminothermically produced steel is poured into a casting mold which surrounds the two rail ends. A cooling agent is applied to the surfaces of the rail heads of the rail portions adjacent the two casting mold halves. The cooling agent is applied after the molten steel has been poured into the casting mold until the steel has solidified. The cooling agent may be applied until the projecting material and the casting mold halves has been sheared off. A casting mold for carrying out the method includes two casting mold halves which each has a groove for receiving a sealing paste in the inner surfaces thereof facing the rail ends, wherein the groove extends along the outer contour of the casting mold halves.

Growing community of inventors

Ratingen, Germany

Frank Kuster