Materials Encyclopedia

The most widely used austenitic stainless steel. Grade 304 offers excellent corrosion resistance in a wide range of environments. 304L (low carbon) provides improved weldability and resistance to intergranular corrosion after welding. Ideal for general industrial piping, food processing equipment, and architectural applications.

The marine-grade stainless steel. Addition of molybdenum (2-3%) significantly improves resistance to chlorides, acids, and pitting corrosion. 316L (low carbon) is the preferred choice for all welded applications. The standard material for offshore, desalination, and chemical processing industries.

Titanium-stabilized austenitic stainless steel for elevated temperature service up to 900°C. The titanium addition (5×C minimum) prevents chromium carbide precipitation during welding and high-temperature exposure. 321H (high carbon, 0.04-0.10% C) provides enhanced creep strength above 540°C. The standard material for refinery heater tubes, boiler superheaters, and exhaust systems.

Niobium-stabilized austenitic stainless steel offering higher temperature strength than 321. Niobium (columbium) stabilization prevents intergranular corrosion and provides superior creep resistance at temperatures up to 925°C. 347H (high carbon) delivers enhanced high-temperature strength. The preferred grade for refinery hydroprocessing units, thermal oxidizers, and nuclear applications.

High-chromium, high-nickel austenitic stainless steel designed for continuous high-temperature service up to 1150°C. The 25% Cr / 20% Ni composition provides exceptional oxidation resistance and carburization resistance. 310S (low carbon, 0.08% max) resists sensitization and maintains ductility after prolonged high-temperature exposure. Widely used in furnace components, heat treatment equipment, and thermal processing.

Molybdenum-enhanced austenitic stainless steel offering superior corrosion resistance to 316L, especially in acidic and chloride-containing environments. The higher molybdenum content (3-4%) provides improved resistance to pitting and crevice corrosion. 317L (low carbon) is the standard grade for welded applications. Commonly used in flue gas desulfurization, chemical processing, and pulp & paper industries.

High-alloy austenitic stainless steel with superior resistance to sulfuric acid and chloride-induced pitting. The combination of high nickel (23-28%), chromium (19-23%), molybdenum (4-5%), and copper (1-2%) delivers exceptional performance in reducing acid environments. Originally developed for sulfuric acid service, it has become the premium choice for seawater cooling, phosphoric acid production, and pollution control equipment.

Ultra-high molybdenum austenitic stainless steel with PREN ≥ 43 — approaching super duplex 2507 in pitting resistance while maintaining superior ductility and formability. The 6% Mo composition makes it one of the most corrosion-resistant stainless steels available, bridging the gap between standard 316L and expensive nickel alloys. Widely used in seawater handling, bleach plants, and FGD systems.

The most widely used duplex stainless steel. Offers roughly double the yield strength of 316L with superior chloride stress corrosion cracking resistance. The perfect balance of strength, corrosion resistance, and cost for offshore, chemical, and desalination applications. S32205 (enhanced) has tighter chemistry for improved corrosion properties.

Super duplex stainless steel with enhanced chromium, molybdenum, and nitrogen content. Offers significantly higher strength and corrosion resistance than standard 2205. PREN ≥ 40 makes it suitable for the most aggressive chloride environments including hot seawater and sour well conditions. The ultimate alloy for critical offshore and subsea applications.

Super duplex stainless steel with tungsten and copper additions for superior corrosion resistance in the most demanding environments. Higher PREN (≥40) than 2205 with improved performance in hot chloride, sulfuric acid, and sour service. The tungsten addition enhances pitting resistance, while copper provides resistance to sulfuric acid. A direct competitor to 2507 with slightly different optimized properties.

The workhorse nickel-chromium-molybdenum alloy. Outstanding resistance to a wide range of corrosive environments combined with high strength up to 980°C. The addition of niobium provides excellent fatigue and thermal-fatigue strength. Widely used in aerospace, marine, nuclear, and chemical processing — wherever both strength and corrosion resistance are critical.

A nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. Designed for superior resistance to both reducing and oxidizing acids, including sulfuric and phosphoric. The copper addition provides excellent resistance to sulfuric acid — a key differentiator from Inconel 625. Widely used in chemical processing, pollution control, and pickling operations.

The most universally corrosion-resistant nickel alloy available. Outstanding resistance to both oxidizing and reducing environments, including hot contaminated mineral acids, strong oxidizers like ferric and cupric chlorides, wet chlorine gas, and hypochlorite solutions. The first-choice alloy for severe chemical processing where multiple corrosive agents are present.

A nickel-copper alloy (≈ 67% Ni, 23% Cu) with exceptional resistance to seawater, hydrofluoric acid, and caustic alkalis. Known for its high strength and toughness across a wide temperature range from cryogenic to 480°C. The classic marine engineering alloy — used in shipbuilding, offshore, and desalination for over 100 years.

Advanced nickel-chromium-molybdenum alloy with superior resistance to oxidizing environments compared to C-276. The higher chromium content (20-22.5%) provides outstanding resistance to ferric chlorides, cupric chlorides, and other oxidizing media that challenge C-276. Excellent weldability with little loss of corrosion resistance in the heat-affected zone. The most versatile of the Hastelloy C-family for complex mixed-acid environments.

Nickel-chromium-iron alloy with excellent oxidation resistance up to 1093°C. The high nickel content (72% min) provides outstanding resistance to caustic alkalis and chloride stress corrosion cracking. One of the most widely used nickel alloys for thermal processing, chemical process equipment, and nuclear applications. Standard material for steam generator tubing in pressurized water reactors.

Nickel-chromium-iron alloy with aluminum addition for exceptional oxidation resistance up to 1260°C. The aluminum forms a tightly adherent oxide layer that provides outstanding resistance to carburization, sulfidation, and metal dusting — critical performance advantages in petrochemical furnace and reformer applications. Superior to Alloy 600 in high-temperature corrosion resistance.

Iron-nickel-chromium alloy engineered for long-term high-temperature service with exceptional creep and rupture strength. 800H (annealed, 0.05-0.10% C) provides controlled grain size for creep resistance up to 815°C. 800HT (fine-grain, Al+Ti enhanced) extends service to 980°C. A more economical alternative to nickel-based superalloys for many petrochemical and power generation applications.

Precipitation-hardenable nickel-chromium alloy with exceptional strength from cryogenic temperatures up to 700°C. The addition of niobium enables age hardening — delivering yield strength of 1034-1241 MPa in the heat-treated condition. The alloy of choice for gas turbine hot sections, aerospace fasteners, and high-pressure oil & gas wellhead components. Combines extreme strength with good corrosion resistance.

Commercially pure titanium with the highest ductility and formability of all titanium grades. Lowest strength but best corrosion resistance in oxidizing environments. The preferred grade for chemical processing equipment, plate-type heat exchangers, and applications requiring extensive cold forming. Excellent weldability with no post-weld heat treatment required.

The workhorse commercially pure titanium grade — balancing strength, ductility, and corrosion resistance at a reasonable cost. The most widely used titanium grade for industrial applications. Approximately 50% stronger than Grade 1 with only a slight reduction in formability. The standard material for seawater piping, shell-and-tube heat exchangers, and pressure vessels in chloride service.

The most widely used titanium alloy — accounting for approximately 50% of global titanium consumption. The 6% aluminum and 4% vanadium additions create an alpha-beta alloy with dramatically higher strength than commercially pure grades while retaining excellent corrosion resistance. Heat treatable to even higher strength levels. The standard material for aerospace structures, medical implants, and high-performance marine components.