STAINLESS STEEL
RA 253 MA® was developed over 30 years ago when the need for a heat resistant stainless steel with high strength, while maintaining good oxidation resistance was present in the industry. The lean 11% nickel content of RA 253 MA is a key contributor to being cost effective and stable. With the addition of rare earth elements, RA 253 MA still performs well at temperatures up to 2000°F (1093°C), similar to that of 310 stainless steel.
316/316L is the most commonly used austenitic stainless steel in the chemical process industry. The addition of molybdenum increases general corrosion resistance, improves chloride pitting resistance and strengthens the alloy in high temperature service. Through the controlled addition of nitrogen it is common for 316/316L to meet the mechanical properties of 316 straight grade, while maintaining a low carbon content.
17-4 stainless is an age-hardening martensitic stainless combining high strength with the corrosion resistance of stainless steel. Hardening is achieved by a short-time, simple low-temperature treatment. Unlike conventional martensitic stainless steels, such as type 410, 17-4 is quite weldable. The strength, corrosion resistance and simplified fabrication can make 17-4 stainless a cost-effective replacement for high strength carbon steels as well as other stainless grades.
17-4 stainless is an age-hardening martensitic stainless combining high strength with the corrosion resistance of stainless steel. Hardening is achieved by a short-time, simple low-temperature treatment. Unlike conventional martensitic stainless steels, such as type 410, 17-4 is quite weldable. The strength, corrosion resistance and simplified fabrication can make 17-4 stainless a cost-effective replacement for high strength carbon steels as well as other stainless grades.
The 15-5 PH alloy was designed to have greater toughness than 17-4 PH. The 15-5 PH alloy is martensitic in structure in the annealed condition and is further strengthened by a relatively low temperature heat treatment which precipitates a copper containing phase in the alloy. 15-5 PH is also referred to as XM-12 in some specifications.
309 is an austenitic heat resistant alloy with oxidation resistance to 1900°F under constant temperature conditions. When frequent thermal cycling is involved, the alloy is resistant to about 1850°F. The high chromium and relatively low nickel content of 309 provide good resistance to high temperature sulfur bearing atmospheres. 309 has only moderate resistance to carbon absorption and is not suggested for use in highly carburizing atmospheres.
Excellent resistance to oxidation under mildly cyclic conditions through 2000°F characterizes 310. Because of its high chromium and medium nickel contents, 310 has good resistance to sulfidation and other forms of hot corrosion. 310 is widely used in moderately carburizing atmospheres such as encountered in petrochemical environments. The more severely carburizing atmospheres of industrial heat treating furnaces require RA330® or RA333®. 310 is not suggested for the severe thermal shock of repeated liquid quenching.
321 stainless is a titanium stabilized grade commonly used for service in the 1000-1600°F temperature range. For service temperatures up to about 1600°F, a stabilizing treatment at 1550-1650°F, air cool, may be used to provide optimum resistance to intergranular corrosion and to polythionic acid stress corrosion cracking.
A-286 alloy is an age-hardenable iron base superalloy for applications requiring high strength from -320°F up to 1000°F long time, 1300-1500°F short time. Oxidation resistance is high for continuous service to 1500°F, intermittent to 1800°F.
N-50 (XM-19) is a high strength and good corrosion resistant austenitic stainless steel. It has nearly double the yield strength of 304 and 316 stainless steel and has better corrosion resistance than 317L stainless steel. N-50 Stainless remains non-magnetic even after being severely cold worked. It maintains strength at high temperatures as well as sub-zero temperatures.
N-60 is known for its excellent galling resistance, even at elevated temperatures. The additions of 4% silicon and 8% manganese inhibit wear, galling, and fretting. It is commonly used for various fasteners and pins that require strength and resistance to galling. It maintains decent strength up to temperatures of 1800°F and has oxidation resistance similar to that of 309 stainless steel. The general corrosion resistance is between that of 304 and 316 stainless steel.
13-8 stainless is a martensitic precipitation hardening stainless steel that has excellent strength, high hardness, superior toughness and good corrosion resistance. Good transverse toughness properties are achieved by tight chemical composition control, low carbon content, and vacuum melting. Typical applications are large airframe structural components and injection molding equipment.
Type 303 is a non-magnetic stainless steel, which is not hardenable by heat treatment. It is the free machining modification of the basic 18% chromium – 8% nickel stainless steel.
Dual certified 304/304H is used as a material of construction up to 1500°F. Slight scaling begins at about 1200°F. This is the 0.04% minimum carbon version of type 304 stainless. It has general corrosion resistance similar to the low carbon 304/304L. However, it is subject to carbide precipitation in the heat affected zone (HAZ) of welds. Weldments may be sensitive to HAZ intergranular corrosion in oxidizing acid environments, and to polythionic acid stress corrosion cracking. The carbide precipitation is not harmful to high temperature mechanical properties.
317/317L is a molybdenum containing austenitic stainless steel, with improved corrosion resistance over 304/304L and 316/316L stainlesssteel. The increased levels of chromium, nickel, and molybdenum over 316L stainless steel improve chloride pitting resistance and general corrosion. Through the controlled addition of nitrogen it is common for 317L to meet the mechanical properties of 317, while maintaining a low carbon content.
Type 347 stainless steel has slightly improved corrosion resistance over type 321 stainless steel in strongly oxidizing environments. Type 347 is stabilized with columbium, it is preferable for aqueous and low temperature environments due to its good resistance to intergranular attack. Both 347 and 321 offer good resistance to polythionic acid stress corrosion cracking, encountered in oil refineries. The high temperature oxidation resistance of 347 is similar to that of 304 stainless steel. Useful to 1500°F.
410 stainless is a corrosion and heat resistant 12% chromium steel. It is the most widely used of the hardenable stainless steels. Heat treated 410 has mechanical properties comparable to the engineering alloy steel AISI 4130, coupled with the additional benefit of good corrosion resistance. 410 is highly resistant to atmospheric corrosion. Maximum corrosion resistance is obtained by hardening and polishing.
Alloy 410S stainless steel is a low carbon modification of Type 410 stainless steel. Low carbon and optionally a small addition of titanium and/ or columbium minimize austenite formation at high temperatures, thereby restricting the alloy’s ability to harden. The material remains soft and ductile even when the material is rapidly cooled from above the critical temperature. This low hardening characteristic helps to prevent cracking when the steel is welded or exposed to high temperatures. The alloy is completely ferritic in the annealed condition. 410S is ferromagnetic.
416 stainless steel is a free-machining martensitic stainless steel with 12-13% chromium that can be hardened by heat treatment to higher strength and hardness levels. In the annealed condition, it has better machining properties than typical austenitic stainless steels like 304 & 316.
420 is a hardenable, martensitic stainless steel similar in chemical composition to that of 410, differing primarily in carbon content. 420 stainless steel is leaner in carbon than that of 410 allowing for it to be capable of achieving a higher strength and hardness at the result of lower ductility. 420 offers comparable corrosion resistance to that of 410 and is commonly utilized for applications requiring high strength, high wear resistance, or good edge retention.
Stainless 440C is a high-carbon martensitic stainless steel. As a martensitic stainless steel, 440C is magnetic and can be hardened by heat treatment. The high carbon content in 440C provides high hardness and strength. Despite this carbon content, the chromium content is sufficient to retain its stainless characteristics.
446 is a high chromium ferritic heat resistant alloy with excellent resistance to oxidation, sulfidation and other forms of hot corrosion. This grade is most commonly used between 1500 – 2100°F, although its elevated temperature strength is quite low. 446 is the only heat resistant alloy that will tolerate molten copper and brass. As with other high chromium ferritic stainless, 446 embrittles severely in the 700-1000°F temperature range (885°F embrittlement). 446 should not be used in this temperature range unless nearly complete loss of room temperature ductility may be tolerated. Sigma phase embrittlement occurs upon long time exposure in the 1000-1300°F range.
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