With the continuous improvement of the understanding of Duplex Stainless Steel Pipe and the continuous improvement of production level, China’s duplex stainless steel pipe has made great progress and progress in terms of output, steel type and variety in recent years.

China’s duplex stainless steel pipes have gotten rid of the situation of small output and single variety around 2000. While the output continues to increase, the varieties are gradually diversified.

On this basis, the market expansion of China’s duplex stainless steel pipes has also made significant development. China’s duplex stainless steel pipes have moved away from being mainly used in petrochemical and other single industries and gradually expanded to petrochemical, chemical transportation, nuclear power, marine and other applications In addition, China’s duplex stainless steel pipes are also constantly going out of China to open up overseas markets.

Combining with the development of duplex stainless steel pipes in the world and in China, according to the actual situation in China, we will discuss several future development directions:

1) High-quality, continuously improving market competitiveness by improving steel purity and product quality.

2) Low cost, through process optimization and fine control of ingredients, cost control and market competitiveness are improved.

3) Multi-alloying and customization of steel design.

4) The research is more in-depth and refined. On the basis of the previous research, a more in-depth study on the precipitation and control of the second phase was carried out, and the fine control of the phase ratio and morphology was gradually realized.

5) According to the national strategy, continue to expand the application of duplex stainless steel in China.

As a stainless steel seamless pipe manufacturers, Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. will also continue to develop to provide customers with higher quality stainless steel seamless pipes. For more details, please contact us: https://www.yintuosteel.com/product/ferritic-austenitic-duplex/duplex-stainless-steel-seamless-pipe-and-tube.html
1. Stainless steel pipes can be divided into Cr series (400 series), Cr-Ni series (300 series), Cr-Mn-Ni (200 series) and precipitation hardening series (600 series) according to their composition.

2. Stainless steel pipes are divided into seamless pipes and welded pipes according to the production method. Seamless steel pipes can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes and extruded pipes. Cold-drawn and cold-rolled pipes are steel pipes. Secondary processing; welded pipes are divided into straight seam welded pipes and spiral welded pipes.

3. Stainless steel pipes can be divided into round pipes and special-shaped pipes according to the cross-sectional shape. Special-shaped tubes include rectangular tubes, rhombus tubes, oval tubes, hexagonal tubes, octagonal tubes, and various asymmetrical cross-section tubes. Stainless steel pipes can be divided into equal-section pipes and variable-section pipes according to the shape of the longitudinal section. Variable section tubes include tapered tubes, stepped tubes and periodic section tubes.

4. Stainless steel pipes can be divided into smooth pipes and threaded pipes (threaded steel pipes) according to the state of the pipe ends. The threaded pipe can be divided into the ordinary threaded pipe (pipes for conveying water, gas and other low pressure, which are connected by ordinary cylindrical or tapered pipes) and special threaded pipes (pipes for petroleum and geological drilling. For important threaded pipes, use Special thread connection). For some special pipes, in order to compensate for the influence of the thread on the strength of the pipe end, the pipe end is usually thickened (internal thickening, external thickening or internal and external thickening) before turning the wire.

5. According to the purpose, it can be divided into oil well pipe (casing, oil pipe and drill pipe, etc.), line pipe, boiler pipe, mechanical structure pipe, hydraulic prop pipe, gas cylinder pipe, geological pipe, chemical pipe (high-pressure fertilizer pipe, petroleum Cracking pipe) and ship pipes.

Huzhou Nanxun Yintuo Special Material Technology Co., Ltd., as a seamless pipe manufacturer, has seamless pipes for sale. If you want to know more about seamless pipes, you can contact us: https://www.yintuosteel.com/
Stainless steel seamless pipe is an iron-based alloy with a mass fraction of 12% to more than 50% alloying elements. Alloying elements affect the stability of austenite, ferrite and martensite phases, thereby affecting the balance between the phases related to stability.

The elements added to the stainless steel tube can be divided into elements that form and stabilize ferrite and elements that form stable austenite. Martensite is a phase transformation product that is formed when austenite is cooled from high temperature to low temperature. If austenite is not formed at high temperatures, then martensite cannot be formed at low temperatures.

Austenitic stainless steel pipes contain high nickel content and other austenite-forming elements, which promote the formation of the austenite phase, making it stable at room temperature or even lower temperatures.

Ferritic stainless steel seamless pipes contain elements that weaken the formation of austenite, such as high chromium content, making ferrite the dominant phase component. The martensitic stainless steel tube is austenitic at high temperatures, but this austenite is suitably unstable and transforms when it is cooled. The microstructure of the stainless steel tube can be controlled by the balance between the austenite forming element and the ferrite forming element. The adjustment of the balance between the two elements plays an important role in the mechanical properties, corrosion resistance and weldability of stainless steel pipes.

The addition of aluminum, titanium, copper and molybdenum to the stainless steel seamless tube can promote the precipitation reaction and strengthen the steel. Austenitic stainless steel seamless tubes often contain titanium and aluminum to form nickel-titanium and nickel-aluminum precipitation phases, which are similar to precipitation strengthening phases in nickel-based superalloys. Aluminum is a ferrite-forming element in solid solution, while copper is a weak austenite-forming element. The precipitated phase with a composition close to pure copper can be used to strengthen martensitic steel.

Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. produces high-quality austenitic stainless steel seamless tubes. If you need to order seamless pipes and other products, we may be your good partner: https://www.yintuosteel.com/
The petroleum and petrochemical industry is a pillar industry of the national economy, and it occupies a pivotal position in the national economy. In the past 20 years, the production technology level of stainless steel pipes, whether seamless pipes or welded pipes, has been greatly improved. The stainless steel pipes produced by some Chinese manufacturers have reached a level that can completely replace imported products, realizing the localization of steel pipes.

In the petroleum and petrochemical industry, stainless steel pipes are mainly used in pipeline transportation systems, including high-pressure furnace pipes, piping, petroleum cracking pipes, fluid transmission pipes, heat exchange pipes, etc. Stainless steel is required to perform well in wet and acid service conditions.

In order to adapt to the processing of low-quality crude oil and to meet the requirements of environmental protection, Chinese refining and chemical companies continue to optimize the processing structure of the refining unit and adjust the product structure. Among them, high-pressure hydrogenation units such as hydrocracking and hydroprocessing have developed rapidly in recent years. The processing capacity of the unit is It is also constantly improving.

Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. also keeps pace with the times and produces austenitic stainless steel seamless tube, ferritic stainless steel seamless pipe and tube and other kinds of seamless steel tubes. If you need to order our products, you can contact us: https://www.yintuosteel.com/product/austenitic/austenitic-stainless-steel-seamless-tube.html
The method of using an acid solution to remove oxide scale and rust on the surface of the steel is called pickling. Iron oxides such as scale and rust react chemically with the acid solution to form salts which are dissolved in the acid solution and removed. Acids for pickling include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid and mixed acids.

The dipping and pickling method is generally used, and the spray method can be used in mass production. Steel parts are generally pickled in a 10%-20% sulfuric acid solution at a temperature of 40°C. When the iron content in the solution exceeds 80g/L and the ferrous sulfate exceeds 215g/L, the pickling solution should be replaced. At room temperature, the steel is pickled with 20%-80% hydrochloric acid solution to prevent corrosion and hydrogen embrittlement.

Since acid has a great corrosion effect on metals, corrosion inhibitors should be added. After cleaning, the metal surface becomes silvery white, and the surface is passivated to improve the corrosion resistance of stainless steel. In order to eliminate the surface adsorption of the diatomaceous earth carrier and reduce the tailing of the chromatographic peak, the carrier needs to be acid washed or alkaline washed before use. Pickling is to soak the carrier with 6mol/L hydrochloric acid for 2 hours or heat and soak with concentrated hydrochloric acid for 30 minutes, filter, wash with water to neutrality, and dry. Pickling can remove iron, aluminum, calcium, and other impurities on the surface, but cannot remove silanol groups. The pickling carrier is suitable for the analysis of acidic samples.

Degrease and rust the surface of precision seamless steel pipes, and prepare for the next process. In the production process, the pickling process is to remove the surface oxide scale, after which it undergoes lubrication treatment, and then undergoes deep drawing processing. If the steel pipe is not pickled, there may be oxides and oil stains on the surface, and the nuclear energy of the phosphating solution cannot remove them, and the quality of phosphating will be reduced.

Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. is a manufacturer of alloy steel seamless pipe, dedicated to the production of nickel alloy seamless pipe and tube and other seamless pipes. If you need to buy, please contact us: https://www.yintuosteel.com/
The main application range of ferritic stainless steel seamless pipe and tube
Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. mainly provides the development and production of stainless steel seamless pipes. It also includes ferritic stainless steel seamless pipe and tube. If you want to know the relevant information, please click the link: https://www.yintuosteel.com/

Stainless steel seamless pipe is a long strip of steel with a hollow section and no joints on the periphery. The thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, its processing cost will rise substantially. Seamless steel pipes are tubular sections or hollow cylinders, usually but not necessarily circular cross-sections, and are mainly used to transport flowable substances-liquids and gases (fluids), slurries, powders and small solids.

There are various methods of manufacturing and producing pipes. Welded type, seamless type and other types have different uses and have different mechanical properties. The absolute roughness of stainless steel seamless pipe is smaller; it means higher dimensional accuracy. This is useful in sensitive applications and does not require much processing after production. Seamless pipes are usually cold drawn, while stainless steel welded pipes are produced by welding. Stainless steel Erw tubes are resistance welded and are made by welding long metal bars into a cylindrical shape.

Seamless stainless steel pipes have been widely used in petrochemical, boiler, nuclear power, machinery, shipping, water conservancy and other industries.

Ferritic stainless steels are classified into the 400 series, with a chromium content of usually 10% to 30%, and are usually selected for their excellent corrosion resistance and high temperature oxidation resistance. Ferrite has higher strength than carbon steel and has advantages in many applications that require thinner materials and reduced weight (such as automotive emission control systems). They cannot be hardened by heat treatment and are always magnetic. Typical applications of ferritic stainless steel include petrochemicals, automotive exhaust systems and decorations, heat exchangers, furnaces, household appliances and food equipment.

If you are interested in buying ferritic stainless steel seamless pipes, please contact the appropriate supplier of the seamless pipe manufacturer: Huzhou Nanxun Yintuo Special Material Technology Co., Ltd.