Steel Cord Production Processes Research

Cord is the rubber products,especially the radial tyres skeleton material.With the car ownership increased rapidly in China,the automobile tires market increasing demand.Cord has high strength,small deformation,good heat dissipation,the characteristics of fatigue performance,and broad prospects for development.Cord production processes research has far-reaching significance.In this paper,contrast of lead bath quenching and water bath quenching,found that two methods of quenching steel wire metallography are most of lamellar sorbate,and both have a small amount of ferrite,but the water bath quenching ferrite more than lead bath quenching;The average tensile strength of water bath quenching steel wire than the lead bath quenching lower 10-20MPa,and the average surface shrinkage rate water bath quenching than lead bath quenching higher 3-4%,but the mechanical properties of water quenching more stable;The average broken wire level of water quenched steel wire than the lead bath quenching lower.Through the comprehensive comparison,water bath quenching can completely replace the lead bath quenching to achieve the effect of energy saving emission reduction,and the protection of the environment.In the wet pull production wire from ?0.77 stretched to ?0.15,ceteris paribus,19 times drawing the average compression rate is 15.8%,the average tensile strength is 3827 MPa,18 times drawing the average compression rate is 16.6%,the average tensile strength is 3866MPa,the average compression rate increased 0.8%,tensile strength was increased by 39MPa.By collecting some welding decollations,observed these welding decollations by microscope,test the tensile strength and shrinkage rate of the samples compared with normal steel wire,after analysis found that the welding wire fracture is brittle fracture,by adding once tempering and increased the tempering time from 15 seconds to 20 seconds,and the original 50 mesh sandpaper change into 200 mesh sand paper to grind,After the improvement,test the tensile strength and shrinkage rate was improved significantly.Select 3+9×0.175HT cord DTS9 machine as the research object,using different size of the friction plate to change the pay-off tension of the double twisting machine,test the pay-off tension and cord quality found when core pay-off tension is greater than 439N monofilament tension is greater than 22 1N,the number of broken wires obviously increase,and the flywheel ring wear was intense,its service life was shorten in the process of double twist.When the cord pay-off tension is less than 304N monofilament tension is less than 149N there were a lot of twisted flowers,uneven length of lay,core stock out of cord quality problems.When pay-off friction plate size is 30/40,core friction plate size is 35/45,performance index for the best.At the same time by adjusting a twist ratio to measure the torsion value and whether the cord is loose,experiments show that when twist ratio is less than 0.9 reverse value is negative,and there will be a loose phenomenon,with the increase of twist ratio reverse value to the positive tendency,the best twist ratio parameter is 90?110%.Through a series of experiments and data analysis based on the experimental results,reduced the wires broken rate in the actual production,improved the production efficiency and products quality.