ASTM A403 / ASME SA403 WP321H Stainless Steel Fitting Seamless 180° Elbow B16.9

ASTM A403 / ASME SA403 WP321H Stainless Steel Fitting Seamless 180° Elbow B16.9

ASTM A403 standard is a standard developed by the American Society for Testing and Materials, which provides detailed specifications for the materials, manufacturing processes, heat treatment methods, chemical composition, mechanical properties, dimensional tolerances, and other aspects of austenitic stainless steel fittings used in pressure piping systems. WP321H is an austenitic stainless steel grade under ASTM A403 standard, which adds a certain amount of titanium element (at least five times the carbon content, but not higher than 0.70%) on the basis of WP321 material to increase the stability of the product during use.

ASTM A403 WP321H Stainless Steel Chemical Composition

What is the difference between WP321H and WP321?

In the standard, the upper limit of carbon content for ordinary WP321 material is usually 0.08%, but there is no specific range, and the requirements are broader (such as 0.08% max). The WP321H material explicitly requires a carbon content between 0.04-0.10%, and usually requires a minimum carbon content (such as ≥ 0.04%). At the same time, specific heat treatments such as solid solution treatment are needed to ensure that carbides can effectively precipitate and strengthen when working in high-temperature environments. Overall, WP321H material is a version optimized for high temperature strength.

ASTM A403 WP321H Stainless Steel Elbow Heat Treatment

ASTM A403 WP321H Stainless Steel Elbow Tensile Requirements

ASTM A403 TP321H Stainless Steel Seamless Elbow Application:

The core application areas of ASTM A403 WP321H stainless steel seamless elbows are mainly divided into two types: high temperature and high pressure pipeline systems and applications that require resistance to intergranular corrosion.

1.High temperature and high pressure pipeline system:

• Petrochemical industry: furnace tube outlet/inlet pipelines for cracking furnaces, conversion furnaces, reforming furnaces, high-temperature process pipelines, hot oil systems, etc.

• Thermal power generation industry: boiler superheater, reheater connecting pipeline, main steam pipeline, high-temperature reheating pipeline, extraction steam pipeline, etc.

• Nuclear power industry: High temperature pipelines for some auxiliary systems.

• Refining industry: High temperature pipelines for atmospheric and vacuum distillation, catalytic cracking, hydrocracking and other units.

2.In situations where intergranular corrosion resistance is required:

• In situations where intergranular corrosion resistance is required: even if the operating temperature is not high, pipeline systems that are prone to intergranular corrosion after welding or may be exposed to processes that cause sensitization temperature range (425-870 ° C) need to be avoided (such as certain chemical processes).