High strength ASTM A789 S31803 duplex welded tube for oil and gas industry

Parameter Table：

ASTM A789 S31803 welded tube：

ASTM A789 S31803 is a duplex stainless steel material with 50% austenite and 50% ferrite structure, combining the advantages of both. Its mechanical strength is higher than that of ordinary austenitic stainless steel, and its tensile strength and yield strength are excellent. This material shows excellent corrosion resistance in a variety of corrosive environments, especially pitting corrosion, crevice corrosion and stress corrosion cracking caused by chlorides. In addition, S31803 also has good wear resistance, fatigue resistance and good welding performance. It is a high-performance material with stable structure and long service life.

ASTM A789 S31803 welded pipe is widely used in oil and gas, marine engineering, chemical processing, pulp and papermaking, desalination equipment, heat exchangers, boiler systems and other fields due to its excellent comprehensive performance. It is particularly suitable for fluid transportation and structural support in highly corrosive environments, such as desalination pipelines, oil and gas transportation systems and chemical equipment that are subjected to pressure and corrosion. This material has become an ideal choice to replace traditional stainless steel materials due to its high cost performance and reliability.

Chemical composition：

Physical properties：

Quality control method：

Secondary inspection of raw materials

The raw materials used by MTSCO are all from well-known Chinese steel mills, such as Baosteel, Qingshan, TISCO, Dongfang Special Steel, etc., to ensure reliable quality. Each batch of raw materials must provide a material certificate (MTC) and PMI (spectral analysis) report. After the raw materials arrive at the factory, we will also conduct a secondary PMI test to ensure that they fully meet the production requirements and eliminate the risk of unqualified raw materials.

Production management with traceability throughout the process

MTSCO's welded pipes are mainly formed by rolling (RBE) and bending, using PAW+GTAW automatic welding process to ensure full weld formation and stable quality. We have upgraded the technology based on traditional processes, especially for large-diameter thick-walled welded pipes. Problems such as out-of-round welds have been optimized. At the same time, a 12-meter-long annealing furnace is used for solid solution treatment to make the annealing effect more uniform and thorough. The production process is supervised by experienced engineers and quality inspectors throughout the process. Each process is recorded and photographed for archiving, and the whole process is traceable in combination with the process flow card.

100% quality inspection before leaving the factory

Before leaving the factory, MTSCO conducts a comprehensive quality inspection on each welded pipe, including basic inspections such as appearance, size, quantity, PMI, as well as mechanical property testing, hardness testing, X-ray flaw detection, ultrasonic testing (UT), eddy current testing (ET), water pressure testing, etc. The maximum supported water pressure test is an outer diameter of 630mm, and the weld part is 100% X-ray non-destructive testing. We also support the verification of third-party testing agencies such as SGS, TUV, BV, etc. to ensure that each batch of products is of reliable quality and meets the standards.

Product Packaging：