UNS S32750 Duplex Stainless Steel Pipe

UNS S32750 duplex stainless steel pipe is that the characteristics of both ferrite and austenite microstructures. This special duplex stainless steel structure endows S32750 material with excellent corrosion resistance, high strength, and good resistance to stress corrosion cracking.

Duplex stainless steel pipes also have a lower linear expansion coefficient, which makes it have better dimensional stability at high temperatures. These characteristics make duplex stainless steel pipes widely used in petroleum, chemical, seawater desalination, paper making, and many other industrial fields.

Characteristics Of UNS S32750 Duplex Stainless Steel Pipe

The UNS S32750 duplex stainless steel pipe has high resistance to pitting and crevice corrosion, and its high chromium and molybdenum content also gives it strong resistance to overall corrosion of organic acids such as formic acid and acetic acid.

High Precision: ASTM A790 pipes are manufactured with strict dimensional tolerances, ensuring consistent and accurate dimensions along their entire length.

Smooth Surface Finish: These pipes have a smooth surface finish, which is essential for applications where fluid flow or the passage of precision instruments is involved.

Uniform Mechanical Properties: Precise control over the manufacturing process results in uniform mechanical properties, including tensile strength, yield strength, and elongation, which is important for reliable performance.

Customizable:ZIZI can be produced in various sizes, shapes, and grades to meet the specific requirements of different industries and applications.

Chemical Composition

The carbon content of UNS S32750 duplex stainless steel pipe shall not exceed 0.03%, manganese shall not exceed 1.20%, nickel shall be between 6.0% and 8.0%, chromium shall be between 24.00% and 26.00%, molybdenum shall be between 3.00% and 5.00%, and nitrogen shall be between 0.24% and 0.32%.

Materials equivalent to UNS S32750 include ASTM A790 UNS S32750, Super Duplex 2507, and 1.4410.

Mechanical Properties

Tensile strength of UNS S32750 duplex stainless steel pipe σ B ≥ 800Mpa, yield strength σ B ≥ 550Mpa, elongation δ≥ 15%, hardness ≤ 300 (HB). Compared to ordinary austenitic stainless steel, S32750 has higher yield strength and tensile strength, making it suitable for applications that require high pressure and load resistance.

Heat Treatment

From a physical performance perspective, the density of S32750 duplex stainless steel is 8.03g/cm3.The melting point range is 1300~1390 ℃. In terms of heat treatment, the material needs to be insulated between 1025~1125℃ for 1-2 hours, followed by rapid air or water cooling.

Main Features of UNS S32750 Super Duplex Stainless Steel

◆ UNS S32750has excellent corrosion resistance in a wide variety of corrosive chemicals

◆ Outstanding resistance to pitting and crevice corrosion in seawater and other chloride containing environments, with Critical Pitting Temperature exceeding 50°C

◆ High strength compared to austenitic and 22%Cr duplex stainless steels

◆ Excellent ductility and impact strength at both ambient and sub-zero temperatures

◆ High resistance to abrasion, erosion and cavitation erosion

◆ Excellent resistance to stress corrosion cracking in chloride containing environments

◆ UNS S32750is listed in NACE MR 01 75 for sour service

◆ ASME Approval for Pressure Vessel application

ASTM A790 Specification

ASTM A790 is the standard specification for seamless and straight seam duplex (austenitic ferrite) stainless steel pipes. The ASTM A790 standard requires that the chemical composition of duplex stainless steel must meet the specified range, and that the pipeline must have certain mechanical properties, such as tensile strength, yield strength, elongation, and hardness. And it also specifies the size range and tolerance of duplex stainless steel pipes, as well as the surface treatment requirements for pipes, such as cleaning, oil removal, and sandblasting. In order to ensure the quality of pipelines, the ASTM A790 standard requires various inspections of duplex stainless steel materials, such as chemical composition analysis, tensile testing, impact testing, hardness testing, diffusion testing, metallographic analysis, and non-destructive testing.

ASTM A790 pipe specifications are mainly applicable to sizes ranging from 1/8” to 30” (DN6 to DN750). The wall thickness of these steel pipes must comply with ASME B36.19 standards, and the wall thickness grades are SCH 10, SCH 20, SCH 40, STD, XS, SCH 100, SCH 120, SCH 160, XXS.

Features

Material Composition: The standard covers duplex stainless steel, which is characterized by a balanced microstructure of austenite and ferrite. This composition offers superior mechanical properties and corrosion resistance compared to standard austenitic stainless steels.

Seamless and Welded: The specification includes both seamless and welded pipes, offering flexibility in manufacturing and application.

Corrosion Resistance: Duplex stainless steel pipes under this specification exhibit excellent resistance to a wide range of corrosive environments, including chlorides and sulfides, making them ideal for use in harsh conditions.

Mechanical Properties: The duplex structure provides high strength and good impact toughness, which is advantageous in many industrial applications.

Application

The application range of UNS S32750 stainless steel pipe is quite extensive, mainly reflected in the following aspects:

Chemical Process Industry: Due to its high corrosion resistance UNS S32750 is ideal for use in Nitric Acid Processes, Polypropylene Production, PVC Production, Dioxide, Caustic Evaporators, and Equipment.

Marine Industry and Shipbuilding: Propellers and Shafts, Rudders, Shaft Seals, Pumps, Bolts and Fasteners, Valves, Instrumentation, Oil and Chemical Tankers.

Oil and Gas Industry: Pumps, Valves, Pipe, Vessels, Wellhead Equipment, Subsea Equipment.

Pollution Control: Fans and pumps, Wet Scrubbers, Incinerators.

Pulp and Paper Industry: Black liquor heater tubes, Digester Blow Valves, Rotary Feed Valves, I.D.Fans, Brownstock Washers, Precipitators, Bleaching Components.

Food Industry: Sugar Cane Centrifuges, Corn and Vegetable processing plant.

Agrochemicals: Fertilizer Production (Wet phosphoric acid).

Civil Engineering: Sewage Treatment.