Stainless steel welded pipe, referred to as welded pipe, is a steel pipe made by welding commonly used steel or steel strip after crimping through a unit and a mold. Welded steel pipes have simple production process, high production efficiency, many varieties and specifications, and low equipment investment, but their general strength is lower than seamless steel pipes.
Since the 1930s, with the rapid development of high-quality strip continuous rolling production and the advancement of welding and inspection technology, the quality of welds has been continuously improved, and the variety and specifications of welded steel pipes have increased, and in more and more fields, especially in Heat exchange equipment uses pipes, decorative pipes, and medium and low pressure fluid pipes to replace seamless steel pipes.
Features
First, the small-caliber stainless steel welded pipe 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, the lower its input-output ratio; secondly, the process of the product determines its advantages and disadvantages. Generally, welded steel pipes have 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 aesthetics in high-precision, medium and low-pressure fluid applications.
Welding characteristics
According to welding technology, it can be divided into automatic welding and manual welding. Automatic welding generally uses submerged arc welding and plasma welding, and manual welding generally uses argon arc welding.
Classification
According to the weld form, it is divided into straight seam welded pipe and spiral welded pipe.
According to the purpose, it is divided into general welded pipes, heat exchanger pipes, condenser pipes, galvanized welded pipes, oxygen-blowing welded pipes, wire casings, metric welded pipes, roller pipes, deep well pump pipes, automotive pipes, transformer pipes, and electric welded thin-walled pipes. Pipes, electric welded special-shaped pipes and spiral welded pipes.
Usage
GB/T12770-2002 (Stainless steel welded steel pipe for mechanical structure). Mainly used in machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.
GB/T12771-2008 (Stainless steel welded steel pipe for fluid transportation). Mainly used to transport low-pressure corrosive media. Representative materials are 06Cr19Ni10, 022Cr19Ni10, 06Cr19Ni110Ti, 00Cr17, 0Cr18Ni11Nb, 06Cr17Ni12Mo2, etc.
Demand outlook
With the rapid development of my country's economic construction, the consumption of stainless steel continues to increase, and the demand for stainless steel pipes is also increasing day by day, and the market prospects are promising. The market demand of stainless steel seamless pipes is manifested in basic industries, such as petroleum, chemical, power generation, etc., and its demand accounts for one-third of the total consumption of stainless steel seamless pipes. There are also automobile, shipbuilding, construction and environmental protection industries. Greater demand. Stainless steel welded pipes are mainly used in heat exchanger pipes, fluid pipes, pressure pipes, pipes for mechanical structures, urban landscapes, and other industries. The annual consumption is about 700,000 tons. The demand for industrial stainless steel welded pipe is relatively high, and the production process is mature. The annual volume of industrial stainless steel welded pipe in my country is about 150,000 tons, and some of it still needs to be imported. Hangao Tech (SEKO Machinery) high-precision industrial stainless steel welding pipe machine is equipped with an intelligent control system, which can record welded pipe production data in real time and can be stored for up to one year. The performance of welded pipes produced by this equipment can be comparable to seamless steel pipes of the same specification, but the cost is much lower than the production cost of seamless steel pipes. From the perspective of domestic stainless steel pipe products, the steel type is mainly austenitic steel; the product varieties include: seamless steel pipes including cold drawn pipes, cold rolled pipes, hot extruded pipes, centrifugal cast pipes, and spinning pipes; welded pipes include : Welded pipes such as plasma welding, argon arc welding, submerged arc welding, light speed welding and high frequency welding. The stainless steel pipes that can be produced basically cover the specifications of various countries in the world, and the specifications and varieties of stainless steel special-shaped pipes are more than one hundred. , Product uses involve many fields of industry and civil use. However, in general, domestic stainless steel pipes have a certain gap with market demand in terms of varieties, specifications, and quantities.
