Development And Technology Optimization Of New Special Flux For Electroslag Pressure Welding Of Bars

Electroslag Pressure Welding of Bars (ESW) that two bars placed into vertical or oblique (the inclination of4:1range) butt form, it use of welding current through the gaps of two bars generate heat of the arc and resistance in the solder layer to melt bars and pressure to complete a welding method. ESW has the following characteristics: easy to use, reliable of welding quality, high equipment utilization and welding efficiency, low labor intensity, easy to operate, etc.while HRB500(IVgrade) bars to replace HRB400(III grade) bars that not only save steel and reduce the cost, reduced the number of steel at the same force conditions, increasing the gap of the bars, to improve a variety of bars welding, banding and concreting space,5bring convenience to the construction process and ensure the construction quality of the bars concrete. However, there is little the special flux suitable ESW of IVgrade bar, laid the significance of developed the special flux of ESW.This paper analyzes and summarizes the shortcomings during welding IV grade bars use the flux of Currently used in welding of ESW with III grade bars:arcing resistance and arc stability is poor, slag inclusion, welding package forming is poor, tensile strength is low, plasticity and toughness is not enough, etc, Development of a special flux applied ESW of IV gradel bars.To solve the shortage of traditional welding flux IV grade bars, analyzed and summarized the effects of process performance and mechanical properties with component changes in the traditional flux component with the flux above problems, such as arc stability is poor when CaF2increased, need to add the alkali metal or alkaline-earth element to the flux; capabilities of MnO viscosity, fluidity and sulfur removal on the flux; added TiO2in the flux to make acicular ferrite content increased of the weld. Based on this, designed a flux formulation of diverse slag system and adopt four factors and three levels orthogonal test trial of the flux, some group numbers of the flux orthogonal experiment to meet the basic flux welding requirements of IV grade ESW.Components of Best flux and deposited metal are able to meet the basic requirements with IV grade ESW were analyzed and summarized, and optimizes the flux formulation. After optimization of the flux improve overall performance of IV grade ESW, and the flux can also match wire of H08A and H10Mn2to welding Q235A steel, and match EH14wire to welding EH36steel.Through the study of the flux about selection of raw materials, proportion share of chamotte, order of charging, selection of granulation method, melting current, installed furnace capacity, refining time in the smelting to optimize the melting process of the flux.While the welding process of the flux is optimized, mainly from the power device types, the particle size of the flux, and the welding parameters are optimized.Through application of experiments and actual site, he steel plant, proved that the special flux used in practical applications has considerable prospects.