On the Application of Cardan Shaft in Hot Strip Steel Rolling

As we all know, the production process of the steel manufacturing industry is a typical process industry. The rolling process includes the supply of raw materials, iron making, steel making, continuous casting, hot rolling, cold rolling, and heat treatment. It is characterized by long production process. Problems in any one of the links may affect the normal operation of the entire production.   Hot-rolled strip steel refers to strips and plates produced by hot rolling. The general thickness is 1.2 to 8mm. Strips with a width of less than 600 mm are called narrow strip steel, and those with the width of more than 600 mm are wide strip steel.   The cardan shaft of the hot strip rolling mill is a very important transmission component in the entire rolling system, which affects the whole production team and the product quality.   The technical requirements for hot-rolled strip steel consist of four aspects:

1. High dimensional accuracy
2. Good flat shape
3. Good surface quality
4. Good performance

  In the past years, gas furnaces were used to heat the billets. The heating temperature of the entire 6m billet was not uniform. There was a difference of tens of degrees between the temperature of the two ends of the billet, and the rolling force to the mill roll was completely different. The deviation can even be as high as 1.5 times. The cardan shaft has been overloaded for a long time, so the frequency of cardan shaft damage is very high.   Frequent replacement of cardan shafts results in long downtime, which can have a significant impact on yield and quality. This heating mainly controlled heating temperature, time, speed and temperature system (including preheating section, heating section and soaking section temperature) to prevent overheating, overburning, oxidation, decarburization or sticking steel and other phenomena.   After investigation, we discovered these problems and improved the torsional capacity of the universal shaft of the strip mill. The result of rolling mill application showed that the replacement frequency of the cardan shaft was reduced.

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We chose high-quality 35CrMo alloy steel as the raw material for flanged prongs and welding prongs, 20CrMnTi as the material of core component, cross-axis assembly, and ensure that the content of each element of the material can meet or exceed the national regulations through chemical analysis. The mechanical properties of the flanged forkhead and the welding forkhead is improved by the heat treatment so that the cardan shaft can withstand a peak torque of several times or more of the load torque, which greatly reduces the probability of the cardan shaft is twisted. At the same time, we use CNC machine and processing centers to process the flange forks and welding forks. By doing so, not only the degree of cooperation with the host shaft sleeve flange is improved, but also ensure the assembly accuracy of the cardan shaft itself. We have done a lot of protection measures for the cardan shaft in order to make it more adaptable to the harsh environment of rolling mills such as high temperature, dust, and humidity. At the same time, it is also hoped that on-site use of the unit for regular maintenance, if any problems are found during use, timely processing and feedback to contact us.