The article describes the welding process study with the subsequent control of cooling for full-profile rail joints, produced by passing alternating electric current pulses after welding. The welding mode influence on the welded joint quality was investigated. Welding was carried out on a resistance butt welding machine MCP-6301 in conditions of the rail welding company OOO RSP-M (RSP-29). For research, the samples of P65 type full-profile rails of DT350 category 600 mm long were cut out. The isothermal holding conditions after welding were controlled using a personal computer with a change in the program of the SIMATIC S7-300 industrial controller and the software SIMATIC STEP 7, which allows modes of controlled cooling to be set. The control program was written in the LAD graphic language. To search for optimal modes of controlled cooling, a complete factor experiment N = 2k was carried out. Non-heat-treated joints were tested for three-point static bending according to the state standard STO RZD 1.08.002 – 2009 “Railway rails, welded by electric contact method”. Static bending tests were carried out on the press of PMS-320 type. Values of the force arising during bending Pbend and the bending deflection fdef at which the control sample is destroyed, were determined. The maximum values of these indicators were also determined if the sample was not destroyed during the tests. During the experiments, regression models were obtained for output parameters of the bending force and bending deflection. Sample macrostructure and metal hardness distribution on rolling surface of the rails welded joint were studied. A new method of resistance butt welding was developed, which makes it possible to obtain a welded connection of P65 type rails of DT350 category with properties that exceed the technical requirements of the mentioned state standard.

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差热强化钢轨焊接工艺的开发和建模：工业测试

文章描述了焊接工艺研究以及对全截面钢轨接头进行冷却的后续控制，通过在焊接后通过交流电流脉冲产生。研究了焊接方式对焊接接头质量的影响。在轨道焊接公司 OOO RSP-M (RSP-29) 的条件下，在电阻对焊机 MCP-6301 上进行焊接。为研究，截取了600mm长的DT350类P65型全断面钢轨样品。焊接后的等温保持条件是使用个人计算机通过更改 SIMATIC S7-300 工业控制器的程序和软件 SIMATIC STEP 7 来控制的，该软件允许设置受控冷却模式。控制程序是用 LAD 图形语言编写的。为了寻找最佳的受控冷却模式，进行了 N = 2k 的全因子实验。未热处理接头根据国家标准 STO RZD 1.08.002 – 2009“铁路钢轨，通过电接触法焊接”进行三点静态弯曲测试。静态弯曲试验在 PMS-320 型压力机上进行。确定在弯曲过程中产生的力值 Pbend 和控制样品被破坏时的弯曲挠度 fdef。如果样品在测试过程中没有被破坏，也可以确定这些指标的最大值。在实验过程中，获得了弯曲力和弯曲挠度的输出参数的回归模型。研究了钢轨焊接接头滚动表面的试样宏观组织和金属硬度分布。开发了一种新的电阻对焊方法，