Austenitic Stainless Steel

Stainalloy is specialized in the 300-series stainless steels, classified as austenitic steels. These material austenitic grades have chromium (approx. 18 to 30%) and nickel (approx. 6 to 20%) as their major alloying additions. Austenitic stainless steel alloys exhibit excellent corrosion resistance, have a high ease of fabrication, outstanding formability, and tremendous strength at high temperatures and pressure. Austenitic stainless steel is a type of steel alloy which is composed of chromium, nickel, other minor alloys, iron and carbon.

Due to its controlled stainless steel carbon content of 0,04% to 0,10%, stainless steel 304H UNS S30409 provides improved mechanical strength and ensures mechanical integrity up to temperatures of 1500°F.

Stainless Steel 317L UNS S31703

Stainless Steel 317L UNS S31703 is a molybdenum-containing, low carbon austenitic stainless steel with increased additions of chromium, nickel and molybdenum for better corrosion resistance and increased resistance to chemical attack from sulfurous, acetic, formic, citric, and tartaric acids. Due to its low carbon content, 317L also provides resistance to sensitization when welded and higher creep, stress to rupture, and tensile strength at elevated temperatures. It is non-magnetic in the annealed condition but may become slightly magnetic after welding.

Stainless Steel 321 UNS S32100

Stainless Steel 321 UNS S32100 is a titanium stabilized austenitic stainless steel with good general resistance to corrosion. It has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation wide range of 800 – 1500°F. It also possesses good low temperature toughness.

Stainless Steel 321H UNS S32109

Stainless Steel 321H UNS S32109 is the higher carbon (0,04% to 0,10%) version of the alloy. It was developed for enhanced creep resistance and for higher strength at temperatures above 1000°F.

Stainless Steel 347 UNS S34700

Stainless Steel 347 UNS S34700 is an austenitic, chromium steel containing Niobium (Nb) (formerly known as Columbium (Cb)) which allows for the elimination of carbide precipitation, and, consequently, intergranular corrosion. 347 is stabilized by the additions of chromium and tantalum. The addition of Niobium (Nb) also allows 347 to have excellent corrosion resistance, even superior to that of 321. Stainless Steel 347H UNS S34709 is the higher carbon composition form of Alloy 347 and demonstrates improved high temperature and creep properties. Stabilizing heat treatment is used to reduce susceptibility to intergranular stress corrosion and embrittlement also to increase high temperature creep strength.

Ferritic stainless steels

The ferritic stainless steels are relatively less expensive for the same corrosion resistance. Ferritic stainless steels are non austenitic stainless steels. Because the ferritic stainless steels are magnetic where the austenitic stainless steels are non-magnetic. But the ferritic stainless steels are often not used. This for several reasons. For example, the ferritic stainless steels lack toughness, as is the case at temperatures below ambient or at thicknesses greater than about 1.5 mm. In addition, there is a lack of great ductility, especially if more than 30% elongation is required. Ferritic stainless steel is also sensitive to embrittlement at high temperatures if they are moderately alloyed.

Stainalloy has extensive experience in supplying these materials for petroleum refineries, heat exchangers, cooling towers, electric generation plants, fertilizer and chemical plants, paper and pulp handling equipment, high temperature and high- pressure chemical processes. Stainalloy has a special focus on the furnaces of petrochemical cracker units for which high temperature and high-pressure resistant materials are essential.

Stainalloy stocks ½” up to and including 48” seamless ASTM A312 300-series stainless steels, manufactured by only the most reputable mills. The pipes are manufactured in accordance with ASTM A312/ASME SA312 and are subject to additional testing that exceeds both industry and client-specific standards such as Shell. In addition to seamless and welded pipes that adhere to ASTM A358, Stainalloy is also able to supply seamless & welded fittings in accordance with ASTM A403, and seamless & welded fittings, flanges & forgings in accordance with ASTM A182.