Stainless steel 304H butt welded pipe fittings

1. Types of Stainless Steel 304H Butt Weld Fittings

Stainless Steel 304H butt weld fittings are a high-carbon version of the stainless steel 304 material fittings, commonly adhering to the ASTM A403 WP304H standard. ASTM A403 is a material standard for austenitic stainless steel butt weld fittings set by the American Society for Testing and Materials (ASTM). Stainless Steel 304H butt weld fittings exhibit excellent high-temperature strength and oxidation resistance, with a carbon content typically between 0.04% and 0.10%, allowing them to maintain good strength and stability in high-temperature environments. Consequently, ASTM A403 WP304H stainless steel butt weld fittings are commonly used in high-temperature, high-pressure, and corrosive environments, such as in the petroleum, chemical, power, and food processing industries.

According to appearance, the types of Stainless Steel 304H butt weld fittings include long-radius/short-radius 90/45-degree elbows, 180-degree bends, equal/unequal tees, equal/unequal crosses, concentric/eccentric reducers, caps, and stub ends, among others, to meet the needs of different piping designs.

2. Detailed Introduction

Stainless steel 304H is a type of austenitic stainless steel where "H" stands for high carbon. Higher carbon content increases the strength and hardness of the steel but reduces its plasticity and toughness. Conversely, with lower carbon content, the steel exhibits better plasticity and toughness, but lesser strength and hardness.

304H stainless steel is a high-carbon version of 304 stainless steel, with carbon content typically between 0.04% and 0.10%. By incorporating a higher proportion of carbon, the material's strength and hardness are enhanced. Carbon also combines with other elements to form compounds such as silicon carbide, which increases the hardness and wear resistance of the steel, and chromium carbide, which further enhances the corrosion resistance of the stainless steel. This results in stainless steel 304H butt weld fittings having superior high-temperature creep resistance, and they can be used at higher temperature ranges, typically up to about 1150°C. Stainless steel 304H butt weld fittings are extensively used in various industrial sectors, including heaters, furnaces, and high-temperature heat exchange equipment in the petroleum and chemical industries.

chemical composition

physical property

• Corrosion Resistance and Weldability:

Due to the increased carbon content, 304H stainless steel material enhances its resistance to high-temperature corrosion and heat resistance. This enables 304H stainless steel butt weld fittings to maintain good strength and stability in high-temperature environments. Additionally, 304H stainless steel also exhibits good weldability, making it suitable for applications that require welding. While 304 stainless steel offers good corrosion resistance at room temperature, it may perform less effectively than 304H in high-temperature environments.

• High-Temperature Performance:

The high-temperature performance of 304H stainless steel butt weld fittings is notable, allowing them to withstand higher temperatures and pressures. Therefore, they are widely used in large-scale boiler superheaters, steam pipelines, and heat exchangers in the petrochemical industry. In contrast, stainless steel 304 butt weld fittings are primarily used in general industrial, food, and medical industries.

In summary, there are significant differences between 304H and 304 stainless steel butt weld fittings in terms of composition, corrosion resistance, weldability, high-temperature strength, and applications. The specific choice of which type of stainless steel butt weld fitting to use depends on the application environment and the requirements of the pipeline system.