Cold drawing methods and requirements for prestressed steel bars in cold-drawn square steel
For the processing of cold-drawn square steel, we can actually use a method of controlling the cold-drawing rate to cold-draw steel bars.In this way, we will find that the cold tensile rate is actually determined by the test results.The cold tensile stress used to measure the cold tensile rate should also comply with relevant regulations.
For the cold-drawn square steel samples tested, there should be no less than 4 samples used. In fact, the average value of them can be used as the actual cold-drawn rate of the batch of steel bars.When the strength of the steel bar is relatively high, when the average cold tensile rate is actually less than 1%, the cold tensile should still be carried out in accordance with I%.
For the cold drawing of prestressed steel bars in cold-drawn square steel, in fact, the stress control method or the cold drawing rate control method can be directly used. In this case, we should also pay attention to the stress control method of cold-drawn grade II, III and IV steel bars used for prestressing. In other words, the cold drawing test of cold-drawn square steel is actually the cold drawing rate of prestressed steel bars. In this regard, it actually has to go through the approval of the factory's technical department.As for the cold drawing rate determined by its test, in fact, we should first pay attention to the cold drawing of the three steel bars, and take three specimens to test the mechanical properties of the three steel bars.
When a series of workpieces of cold-drawn square steel are inspected and qualified, only batch cold drawing can be carried out.For mixed batches of steel bars in cold-drawn square steel, care should be taken that the method of controlling the cold drawing speed cannot be used for cold drawing.If this method is used, it is necessary to measure its cold stretching rate one by one, and then perform cold stretching.
Cold drawing methods and requirements