Calculation of optimal modes for electric-contact welding of rails of mine haulage tracks

[摘要] The choice of thermal regime is based on the exclusion of formation of quenching structures (martensite and bainite), causing additional stresses and cracks which lead to the destruction of rails. After welded joint upset and cooling at the time of reaching the required temperature it is proposed to perform quasi-isothermal exposure by passing pulses of alternating current through the welded joint. The method for calculating the quasi-isothermal exposure is described that depends on the strength of the welding current and different rails section. It is suggested that after welding the rails during quenching, a quasi-isothermal holding is carried out in the temperature range of the formation of the fine-dispersed structure by passing pulses of alternating electric current through the welded joint maintaining this temperature until the end of the transformation. It is shown that the use of quasi-isothermal exposure at a chosen temperature of 600 - 650 °C makes it possible to obtain a finely dispersed structure of the welded seam of rails of mine haulage tracks without additional heat treatment.

[发布机构] Siberian State Industrial University, 42 Kirova Street, Novokuznetsk; 654007, Russia^1

[效力级别] 地球科学

[关键词] Additional stress;Alternating current;Dispersed structure;Fine-dispersed structure;Quasi-isothermal;Temperature range;Thermal regimes;Welding current