US 5,850,962 AGranted

Casting mold for fusion welding of two workpieces

AssigneeElektro-Thermit GmbH

InventorsFrank Kuster, Gerhard Skreba, Michael Steinhorst

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Abstract

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.

Claims14

Dependent claims

A casting mold for the fusion welding of two rail ends (1,2), comprising mold walls which are matched to the rail profile, cover the welded joint and are composed of a refractory material, the casting area otherwise being bounded by the end faces of the rail ends (1,2), a system of risers (9) having the respective cross-sectional area A and air vents (10) having the respective cross-sectional area B being incorporated in the mold walls, the risers (9), the air vents (10), the weld joint and the weld bead (4), which has a width W.sub.B, extending symmetrically with respect to a vertical transverse center plane (3), and the risers (9) and the air vents (10) furthermore being arranged symmetrically with respect to a vertical longitudinal center plane (5) of the rail ends (1, 2), wherein

the centroid of the cross-sectional area A of the at least one riser (9), which is on one side of the longitudinal center plane (5), is arranged at a distance y from the side edge (11) of the rail foot (8), which distance y is defined as a function of the width F.sub.B of the rail foot (8),
the cross-sectional area B, which is located on one side of the longitudinal center plane (5), of the at least one air vent (10) is
selected as a function of the cross-sectional area A of the riser (9),
the value y being in a range from 0.0025 F.sub.B to 0.4000 F.sub.B, and
the value B/2 being in a range from 0.05 A to 20.00 A.

2 more elements

Dependencies are inferred from the claim text.