ASTM A312 253MA UNS S30815 1.4835 Stainless Steel Seamless Pipe

ASTM A312 S30815 stainless steel pipe is a high-performance austenitic stainless steel seamless pipe designed specifically for extreme high-temperature oxidation environments. It exhibits excellent long-lasting oxidation and scaling resistance in air combustion environments, and is particularly suitable for the high temperature range of 900 ° C to 1100 ° C.

ASTM A312 S30815 Stainless Steel Seamless Pipe Chemical Composition

• Chromium provides the basis for high-temperature oxidation resistance to steel pipes, forming a protective chromium oxide layer; Nickel element can stabilize the austenite structure, provide basic high-temperature strength and corrosion resistance;
• Silicon is one of the most important elements in S30815 stainless steel seamless pipes. High silicon content promotes the formation of a dense and adhesive silicate layer beneath the chromium oxide layer at high temperatures. This silicate layer can effectively compensate for cracks and defects in the chromium oxide layer, significantly improve the resistance to cyclic oxidation, and prevent further oxidation and scaling. This is the key to the long-term use of S30815 stainless steel seamless pipes at 1100 ° C;
• Nitrogen element significantly improves the room temperature and high temperature strength and creep resistance of S30815 stainless steel seamless tube through solid solution strengthening, which is superior to carbon and does not damage the corrosion resistance;
• Cerium is another key element in S30815 stainless steel seamless pipes. The rare earth element cerium can refine the grain size, improve the adhesion of the chromium oxide layer, prevent its peeling, and further enhance the long-term stability of S30815 under harsh cyclic oxidation conditions;
• Carbon element provides a certain strength to S30815 stainless steel seamless pipe, but the content is controlled at a low level to balance weldability and intergranular corrosion resistance.

What is the difference between S30815 stainless steel and similar materials?

The core advantage of S30815/253MA stainless steel material is its ability to maintain long-term stability and excellent service life in oxidative high temperature environments (900-1100 ° C) with severe temperature cycling, and it is cost-effective compared to high nickel alloys.

• VS TP304H (S30409): TP304H is the most commonly used heat-resistant austenitic stainless steel, with much lower high-temperature oxidation resistance and strength than S30815, and poor resistance to cyclic oxidation.
• VS TP309S/310S (S30908/S30108): TP309S/310S has a higher chromium nickel content and an upper limit of oxidation resistance temperature of about 1050 ° C/1100 ° C. However, its high-temperature strength is not as good as S30815, and most importantly, its resistance to cyclic oxidation is far inferior to S30815, resulting in higher costs.
• VS N08811 (Incoloy 800H): N08811 belongs to nickel iron chromium alloy. Its high-temperature strength is better than S30815 in the range of 600-900 ° C, and its oxidation resistance is comparable to S30815 in the range of 900-1000 ° C. However, when it exceeds 1000 ° C, S30815's oxidation resistance is usually better. N08811 has better resistance to reducing sulfur corrosion than S30815. The cost is higher.