The rapid development of the industrial economy has overlooked a problem: our environment is getting worse and worse, our breathing is getting more and more difficult, and our elderly have no less than one million patients with respiratory infections due to environmental pollution. The main reasons are Pollution, do not pay attention to the development of energy-saving and environmentally friendly products. Just like many appliances in our lives are made of pure iron, this can also cause rust pollution. Iron oxidizes in air. Over time, the surface of iron utensils will continue to corrode, resulting in an unpleasant odor. Harmful to the local environment. The emergence of stainless steel can alleviate the urgent need, and stainless tubes and pipes can avoid this problem well. Because the steel pipe does not physically change with the oxygen in the air, the stainless steel pipe can be placed in the natural environment for a long time.
With the continuous improvement of our living standards, we are obliged to promote energy-saving and environmentally friendly products. We must pay attention to it. Only by constantly eliminating old products and developing new energy-saving and environmentally friendly products can our environment be effectively improved. Vigorously promote the application and popularization of stainless steel pipes, so that stainless steel pipes can replace old products with serious pollution. We are committed to improving the environment and working hard to promote stainless steel pipes.
According to the rolling process, medical stainless steel tubing is divided into hot-rolled, hot-extruded and cold-drawn (rolled) stainless steel pipes. According to the different metallographic structure of stainless steel, it mainly includes semi-ferritic and semi-martensitic stainless steel pipe, martensitic stainless steel pipe, austenitic stainless steel pipe, austenitic-ferritic stainless steel pipe, etc.
In terms of specifications, the specifications of stainless steel pipe tubings are mainly based on stainless steel seamless steel pipes. For hot-rolled steel pipes, the total length (indeterminate length) of thick-walled precision stainless steel pipes is 1.5-10m, while the total length of hot-extruded steel pipes is greater than or equal to 1m. The wall thickness of cold drawn (rolled) stainless steel pipe is 0.5-1.0mm and the length is 1.0-7m. The length of the pipe with wall thickness greater than 1.0mm is 1.5-8m.
There are about 45 kinds of hot rolled (hot extruded) stainless tubes and pipes with diameters of 54-480mm, and there are about 36 types in total, with wall thicknesses of 4.5-45mm. There are 65 types of cold drawn (rolled) stainless steel pipes with a diameter of 6-200mm, and 39 types with a wall thickness of 0.5-21mm.
The inner and outer surfaces of precision stainless steel pipes and thick-walled pipes shall be free from cracks, folds, cracks, rolling, delamination and scarring. These defects need to be completely eliminated (unless they are used exclusively for machining). And after cleaning the stainless steel pipe wall, its wall thickness and outer diameter cannot exceed negative deviation. Some small surface defects that do not exceed the allowable negative deviation cannot be eliminated.
The allowable depth of stainless steel straight pipe is also required. Hot-rolled, hot-extruded steel pipes, stainless steel pipes with a diameter less than or equal to 140 mm and not more than 5% of the nominal wall thickness, with a maximum depth of less than or equal to 0.5 mm, and cold drawn (rolled) stainless steel pipes of a thickness not greater than the nominal thickness 4% of wall thickness. The depth is less than or equal to 0.3mm.