With the continuous development of process technology, the quality of stainless steel pipe is constantly improving, making it more and more recognized in the process of using. And people in its recognition at the same time, but also put forward higher requirements, hope that in the quality of continuously improve, in performance can continue to break through. Therefore, the development and application of new steel pipe is very necessary.
Ferritic stainless steel has been very hot in recent years. As it usually does not contain nickel alloy elements, the price of the product is much lower than that of austenitic stainless steel. Therefore, ferritic stainless steel is becoming more and more popular in some application fields. But in the production process of stainless steel seamless pipe, the ferritic stainless steel plasticity, toughness and formability are relatively poor, difficult to meet by the pipe to the process of pulling or rolling, seamless pipe, therefore, in the process of production of stainless steel seamless pipe, application of ferritic stainless steel has not been recognized.
In contrast, duplex stainless steel seems to be much better. The so-called duplex stainless steel is in its solid quenched structure, ferrite and austenite phase each half, the general minimum phase content may reach 30%. Compared with ordinary austenitic stainless steel, duplex stainless steel yield strength is higher, and the forming need sufficient plasticity and toughness, its performance can fully meet the various techniques from pipe seamless process requirements. In some special environments, the amount of duplex stainless steel can be reduced by 30-50% by using the amount of austenitic stainless steel, which is helpful to reduce the production cost. The dual advantages of duplex stainless steel pipe have been greatly recognized in terms of performance and cost, and the development prospect of duplex stainless steel pipe is also getting better and better.
Compared with austenitic stainless steel, the nickel content of duplex stainless steel is lower than that of austenitic stainless steel, the price is higher, and the price of nickel austenitic stainless steel is lower. To some extent, the impact of nickel prices is relatively small.
Because the price of duplex stainless steel is less affected by the price of nickel, when the price of nickel fluctuates greatly, the risk of enterprises producing dual phase stainless steel is relatively small.
In foreign countries, duplex stainless steel is widely used in the pulp and paper industry, oil and gas industry, transportation and construction industry. In order to expand its scope of application, enterprises continue to strive to further expand the specifications of duplex stainless steel pipe, improve production capacity. Sandvik developed SAF 2205 duplex stainless steel pipe has been widely used in offshore oil and natural gas, heat exchanger and processing industry of material demanding field.
In China, although dual phase stainless steel pipes have been applied in some industries, the actual use of domestic varieties is relatively small, and due to technical and technological problems, many times can only rely on imported products. The domestic duplex stainless steel pipe has been applied to some cooling pipes at sea, as well as condensed pipes, decomposition pipes and conveying pipes of chemical products, and the effect is better. In the chemical and petrochemical industries, dual phase stainless steel pipes used in many devices are manufactured abroad.
Duplex stainless steel has dual advantages of austenite and ferrite, and has even been used in some areas instead of 316L. At present, the import of duplex stainless steel pipe occupies a considerable market share in china. With the full understanding of the application fields of duplex stainless steel pipes and the continuous progress of process technology, the development of duplex stainless steel pipes will surely cause great attention of Chinese steel pipe enterprises.
Source: China Duplex Stainless Steel Pipe Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)