How to deal with the manufacture of the curved arc r circle of the electric tubular heaters?
The shape of electric tubular heaters, except Cartridge heater and high-density double head electric heating tube, other shapes of electric heating tube will meet the treatment of arc r circle of electric tubular heaters. Under normal circumstances, the smaller R is, the more difficult the industrial production of tubular heaters is, the higher the scrap rate is, the higher the production cost is, resulting in higher transaction price than normal price. Generally, when R is between 15 and 20 mm, there is a great gap between the characteristic condition of R circle and the temperature parameters of effective heating zone of straight line section in the process of using stainless steel electric heating tube, and the service life of electric heating tube of high load products almost accounts for a large proportion, including pressure resistance rate. Because of this reason, the proportion of breakdown is as high as 80%. Therefore, in the manufacturing process, due to the influence of hardness and yield strength and other parameters in the process of r-circle formation, tube breaking and other phenomena have caused great problems to the pipe manufacturing and quality control. In a word, it is a hidden common fault in the electric heating element industry at present. After synthesizing the opinions of various parties, this paper analyzes the relevant contents for application.
Only from the point of view of the process design that the metal tube is filled with magnesium powder and needs to be geometrically formed during pipe making, the main factor causing the pipe fracture in the bending process is that the hardness of the shell material of the stainless steel heating pipe is too large, which has the problem of the selection of raw material and the problem of process. The main material problems such as iron pipe and stainless steel electric tubular heaters are the yield strength caused by too high annealing hardness
