Difference between ASME SA105 and ASME SA266

Industrial production, especially pressure vessels, pipeline systems, petrochemicals, and power sectors, has different material requirements.

As two widely used carbon steel forging materials, ASME SA105 and SA266 are essential in various industrial applications. This article analyzes and compares SA105 and SA266 from the following aspects.

ASME SA105 is mainly used to manufacture metal components that withstand static loads, as well as mechanical and welded parts that do not require complex heat treatment. SA105 is commonly utilized in the production of pipeline components such as pipe flanges due to its good processing performance and moderate mechanical properties. However, it should be noted that SA105 is not suitable for all pipeline components. According to the A105 standard, SA105 material is unsuitable for the production of tube sheets and hollow cylinders for pressure vessels with higher performance requirements.

In contrast, SA266 is designed for pressure vessel components and has a greater stress potential. It not only fits the requirements of standard pipeline components, but it also performs reliably under higher pressure and temperature conditions. As a result, SA266 is frequently utilized to construct pressure vessels and related equipment components with more demanding material performance specifications.

 Carbon content: The carbon content range for both is similar.

 Alloying elements: The content of alloying elements such as manganese and silicon varies, but in general, the content of alloying elements in SA266 is more closely controlled to maintain the materials stable performance.

 Impurity elements: SA266 has stricter controls on the content of impurity elements such as phosphorus and sulfur, which helps to eliminate inclusions and cracks in the steel while also improving its purity and weight.

SA105 may also contain other alloying elements such as chromium, nickel, copper, etc.

There are also significant differences between SA105 and SA266 in terms of weight range.

According to ASME II D, "Forgings made to this specification are limited to a maximum weight of 1000 lb [4540 kg]. Larger forgings may be ordered to Specification A266/A266M."

SA105 is mainly suitable for forgings with small mass, and its maximum mass is usually controlled within 4540kg. This limitation gives SA105 an advantage in the manufacture of small parts, but it is insufficient when larger mass forgings are required.

In contrast, SA266 has no clear upper limit on forging weight, making it more suitable for manufacturing large, heavy equipment components. This makes SA266 occupy an important position in the manufacturing of large pressure vessels, meeting the industrys demand for high-performance, large-size materials.

Smelting and testing are key links to ensure material quality. There are significant differences in the smelting and testing standards between SA105 and SA266. Steel mills are more stringent in the smelting process of SA266, adopting more advanced process technology and stricter testing methods to ensure the quality and performance of their products. This difference allows SA266 to show higher stability and reliability in terms of mechanical properties and corrosion resistance.