Rail weld joints from electric-contact welding in stationary and fi eld conditions, as well as those from aluminothermic welding are weak points on tracks that are easily damaged compared with rails outside the weld joints. Currently, these weak points are the defects connected with lack of penetration in the welding area, burns at the points of poor contact of the rail foot with the current-carrying contact tips, or with defects of the weld joint machining after welding, as well as the local hardness reduction in areas affected by heat after welding, and local heat treatment after welding. Elimination of wide areas of reduced hardness at the weld joint points producing saddles, cracks, and chipping, and promoting rails damage next to such joints is a major challenge for increasing the serviceability of weld joints. This study introduces three avenues for elimination of increased damage of rails at weld joints including:• Improvement of technology and equipment for electriccontact welding and local heat treatment after welding in the stationary and fi eld conditions.• Development of technology and equipment for induction welding in the stationary and fi eld conditions.• Development of technology and equipment for differentiated induction tempering of rails preliminary welded in strings 800 m long.
Large production volumes of rolling stock and track structure require the introduction of effective strengthening methods at a minimum expenditure. This stimulates a search for ways of increasing the service life of parts of railroad transport. Volume-surface hardening is an efficient method of thermal strengthening. The method consists in through or deep furnace or induction heating of parts before hardening and subsequent intense cooling. The hardenability of the steel used is consistent with the thickness of the strengthened layer, which creates a hardness gradient over the thickness of the parts, i.e., a high surface hardness and a ductile core. In turn, this creates a favorable distribution of internal stresses and provides a high cyclic endurance of the parts in operation. The possibility of using volume-surface hardening to strength railroad transport parts is considered with allowance for the special features of their production and operation.
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