Stainless steel In the past 20 years, the production of stainless steel pipes in various countries in the world has been greatly developed, and the level of process technology and equipment has been greatly improved. In the workshop, there have been many effective new processes and high-efficiency new equipment. After more than 40 years of development in the production of stainless steel pipes in China, especially in the past 20 years, the production technology of stainless steel seamless pipes and welded pipes has made great progress. The output, quality and variety continue to increase and improve, and the quality of a few products has reached International advanced level.
The following will lead you to understand the material types and uses of stainless steel pipes.
1. Classification of stainless steel pipes
1. Classification according to production method: seamless pipe-cold drawn pipe, extruded pipe, cold rolled pipe. Welded pipe: (a) Classified by process-gas shielded welded pipe, arc welded pipe, resistance welded pipe (high frequency, low frequency). (B) According to the weld seam-straight seam welded pipe, spiral welded pipe.
2. Classified by section shape: round steel pipe; rectangular pipe.
3. Classification by wall thickness: thin-walled steel pipe, thick-walled steel pipe
4. Classification by purpose: civil pipe: round pipe, rectangular pipe, flower pipe, generally used for decoration, construction, structure, etc.;
Industrial pipes: steel pipes for industrial piping, steel pipes for general piping (drinking water pipes), mechanical structure/fluid conveying pipes, boiler heat exchange pipes, food sanitation pipes, etc. Generally used in various fields of industry, such as: petrochemical, paper, nuclear energy, food, beverage, medicine and other industries have higher requirements for fluid media.
Two, stainless steel pipe material distinction
1. The concept of steel: steel is a material of various shapes, sizes and properties that we need through pressure processing of steel ingots, billets or steel. Steel is an important material indispensable for national construction and realization of the four modernizations. The materialization of stainless steel pipes is widely used and has a wide variety of varieties. According to different cross-sectional shapes, steel is generally divided into four categories: profiles, plates, pipes and metal products. Organize the production, order supply and management of steel products, which are divided into heavy rail, light rail, large section steel, medium section steel, small section steel, cold-formed steel section steel, high-quality section steel, wire rod, medium-thick steel plate, thin steel plate, electrical engineering Silicon steel sheet, strip steel, seamless stainless steel pipe steel, welded stainless steel pipe, metal products and other varieties.
2. The production method of steel: most steel processing is steel processing by pressure, and the materialization of stainless steel pipe makes the processed steel (slab, ingot, etc.) plastically deformed. According to the processing temperature of the steel, the steel is divided into two types: cold processing and hot processing.
The main processing methods of steel are: rolling-the steel metal billet is passed through the gap between a pair of rotating rollers (various shapes), and the cross-section of the material is reduced due to the compression of the rollers, and the length is increased. This is a pressure processing method for producing steel. The most commonly used production methods are mainly used to produce steel profiles, plates, and pipes. It is divided into cold rolling and hot rolling.
Forging steel: a pressure processing method that uses the reciprocating impact of a forging hammer or the pressure of a press to change the blank into the shape and size we need. Generally divided into free forging and die forging, it is often used for the production of large-scale steel, billet and other materials with larger cross-sectional dimensions.
Drawing steel: It is a processing method that draws rolled metal blanks (forms, tubes, products, etc.) through a die hole to reduce the cross section and increase the length. Most of the processing methods are used for cold working.
Extrusion: It is a processing method in which the steel is placed in a closed extruder and pressure is applied at one end to extrude the metal from a prescribed die hole to obtain a finished product with the same shape and size. It is mostly used to produce non-ferrous metal materials. .
Third, the use of stainless steel pipe
1. Seamless steel pipe Stainless steel: Seamless steel pipe is a long steel strip with a hollow section and no joints on the periphery.
The manufacturing process and flow of seamless steel pipe: smelting>steel ingot> rolling> sawing> stripping> piercing> annealing> pickling> ashing> cold drawing> cutting head> pickling> warehousing
The characteristics of seamless steel pipe: It is not difficult to see from the above process flow. First, the thicker the wall thickness of the product, the more economical and practical it is. The thinner the wall thickness, the greater the processing cost. Second, the process of the product determines its limitations. Generally, seamless steel pipes have low precision, uneven wall thickness, low brightness on the inside and outside of the pipe, high cost of sizing, and there are pits and black spots on the inside and outside that are not easy to remove. ; Third, its detection and shaping must be processed offline. Therefore, it embodies its superiority in terms of high-pressure, high-strength, and mechanical structural materials.
2. Welded steel pipe: Welded steel pipe is abbreviated as welded pipe, which is a steel pipe made by welding steel plates or steel strips through a unit and a mold after crimping.
The manufacturing process and process of welded steel pipe: steel plate> stripping> forming> welding> induction bright heat treatment> internal and external weld bead treatment> shaping> sizing> eddy current testing> laser diameter measurement> pickling> storage
The characteristics of welded steel pipes: It is not difficult to see from the above process flow: First, the product is continuously produced online, the thicker the wall, the greater the investment in the unit and welding equipment, and the less economical and practical it is . The thinner the wall thickness, its input-output ratio will decrease accordingly; secondly, the process of the product determines its advantages and disadvantages. Generally, the welded steel pipe has high precision, uniform wall thickness, and high brightness inside and outside the pipe (the steel pipe is determined by the surface grade of the steel plate). Surface brightness), can be arbitrarily fixed length. Therefore, it embodies its economy and beauty in high-precision, medium and low-pressure fluid applications.