ASTM A234 WP11 CL2 Alloy Steel Fitting Buttwelded For Chemical Industry B16.9

ASTM A234 WP11 CL2 Alloy Steel Fitting Buttwelded for Chemical Industry B16.9

ASTM A234 is a standard developed by the American Society for Testing and Materials (ASTM) for carbon steel and alloy steel butt welded pipe fittings used in medium to high temperature services. These fittings are mainly used in pipeline systems in industries such as petroleum, chemical, and power, especially in environments that require high temperature resistance and corrosion resistance.

WP11 CL2 belongs to chromium molybdenum alloy steel, in which the addition of chromium (Cr) and molybdenum (Mo) enhances the resistance to sulfide corrosion and oxidation, and has good high-temperature strength, oxidation resistance, and creep resistance. It is usually used in the temperature range of -29 ° C to 593 ° C and is suitable for high-temperature and high-pressure working conditions.

CL2 is the abbreviation of Class 2, which represents the heat treatment requirements and corresponding mechanical properties of this grade of material. In terms of heat treatment, ASTM A234 WP11 CL2 alloy pipe fittings must be normalized + tempered. Normalizing refers to heating the material to an appropriate temperature above the critical temperature and keeping it warm, and then cooling it in the air, so as to refine the grains, make the structure uniform, and improve the mechanical properties of the pipe fittings; tempering refers to reheating the material to a temperature below the critical temperature after normalizing, usually in the range of 1200°F - 1350°F / 650°C - 730°C, keeping it warm for a period of time, and then cooling it at an appropriate speed. Cooling is usually carried out in the air, so as to reduce the hardness of the material, eliminate internal stress, and improve toughness and plasticity.

ASTM A234 WP11 Alloy Steel Fitting Chemical Requirements

WP11 is further divided into three subcategories based on its composition: Class 1, Class 2, and Class 3

ASTM A234 WP11 Alloy Steel Fitting Mechanical Properties

ASTM A234 WP11 Alloy Steel Fitting Manufacturing and Testing Requirements

• Manufacturing process: ASTM A234 WP11 CL2 alloy steel fittings are manufactured through hot forming or cold forming processes. Common types of fittings include elbows, tees, reducers, caps, etc.
• Heat treatment requirements: ASTM A234 WP11 CL2 alloy steel fittings need to undergo normalizing or normalizing+tempering to eliminate residual stress and optimize mechanical properties.
• Weldability: ASTM A234 WP11 CL2 alloy steel fittings require preheating (recommended 150-300 ° C) and control of interlayer temperature during welding, and stress annealing is required after welding.

ASTM A234 WP11 CL2 Alloy Steel Compared to Other Grades

ASTM A234 WP11 CL2 Alloy Steel Fitting Application

ASTM A234 WP11 CL2 alloy steel fittings are mainly used in piping systems that need to withstand medium to high temperatures and/or pressures:

• Petroleum refining: atmospheric and vacuum, catalytic cracking, hydroprocessing and other units
• Petrochemical: ethylene cracking, reforming and other units
• Thermal power plants: boiler, superheater, reheater piping systems
• Steam transportation systems
• Industrial piping that requires higher performance than carbon steel