Stainless steel comes in different grades and surface finishes, depending on the application it will be used. Stainless steel alloys have a long history of use in the aerospace, marine, laboratory, production, and machinery industry.
Stainless steels have high strength, and toughness. They used at both extremes of the temperature ends, and can be machined into any desired shape with CNC equipment. These characteristics provide outstanding versatility in the most demanding applications.
Stainless steels are selected for their:
|Grade||US Aerospace/Military||US Commercial|
|301 Annealed||AMS 5901 Annealed sheet /strip||ASTM A240 / ASME SA240|
|AMS 5902 3/4 Hard Sheet / Strip||ASTM A666 / ASME SA666|
|301 1/4 Hard||AMS 5517 1/4 Hard Sheet /Strip||ASTM A240 / ASME SA240|
|MIL-S-5059||ASTM A666 / ASME SA666|
|301 1/2 Hard||AMS 5518 1/2 Hard Sheet / Strip||ASTM A240 / ASME SA240|
|MIL-S-5059||ASTM A666 / ASME SA666|
|301 Full Hard||AMS 5519 Full Hard Sheet / Strip||ASTM A240 / ASME SA240|
|MIL-S-5059||ASTM A666 / ASME SA666|
|302||AMS 5500 Laminated sheet||ASTM A240 / ASME SA240|
|AMS 5515 Sheet / strip Hi Ductility||AISI 302|
|AMS 5516 Sheet / strip / plate|
|AMS 5600 Laminated sheet|
|AMS 5636 Bar Cold Drawn 100ksi|
|AMS 5637 Bar Cold Drawn 125ksi|
|303||AMS 5635 303Pb Bar / forging||ASTM A320 Grade B8F Cl1|
|303Se||AMS 5638 Bar / wire / forging||ASTM A320 Grade B8F Cl2|
|303Sulf||AMS 5640 Type 1 303Sulf Bar||ASTM A484 / ASME SA484|
|AMS 5640 Type 2 303Se Bar||ASTM A582 /ASME SA582|
|AMS 5641 303Se Free machine Bar||AISI 303|
|ASM 5738 Free mach, High yield str|
|304||AMS 5501 Sheet / strip 125ksi||ASTM A276 / ASME SA276|
|304L||AMS 5511 Sheet /strip (ann)||ASTM A479 / ASME SA479|
|304LVM (Vac Melt)||AMS 5513 Sheet / strip (ann)||ASTM A484 / ASME SA484|
|AMS 5560 Seamless tube|
|304 Tube||AMS 5563 1/4Hd seamless/welded|
|AMS 5564 1/8Hd seamless/welded|
|AMS 5565 Welded tube|
|AMS 5566 Seamless/welded tube|
|AMS 5567 Seamless/welded tube|
|AMS 5569 Seamless/ welded tube|
|AMS 5575 Welded tube|
|AMS 5639 Bar / Forgings (304)|
|AMS 5647 Bar/Forgings (304L)|
|MIL-T-8506 Seamless /welded tube|
|MIL-T-5695 Seamless / welded tube|
|MIL-T-6845 Seamless / welded|
|MIL-T-8504 Seamless/welded tube|
|MIL-T-6737 Welded tube|
|309||AMS 5523 Sheet / strip / plate||ASTM A276 / ASME SA276|
|AMS 5574 Seamless tube||ASTM A479 / ASME SA479|
|AMS 5650 Bar / tube / forgings||ASTM A484 / ASME SA484|
|AMS 5650 Bar Stock List||ASTM A314 / ASME SA314|
|AMS QQ-A-793||ASTM A580 / ASME SA580|
|310||AMS 5521 Sheet / strip / plate||ASTM A240 / ASME SA240|
|310S||AMS 5572 Seamless tube||ASTM A167 / ASME SA167|
|310S Tube||AMS 5577 Welded tube||ASTM A276 / ASME SA276|
|AMS 5651 Bar / wire / forging||ASTM A479 / ASME SA479|
|QQ-S-763||ASTM A484 / ASME SA484|
|ASTM A176 / ASME SA176|
|316||AMS 5507 Sheet / strip/ plate (316L)||ASTM A240 / ASME SA240|
|316L||AMS 5524 Sheet / strip / plate (316)||ASTM A167 / ASME SA167|
|316LVM (Vac Melt)||AMS 5573 Seamless tube||ASTM A666|
|316Ti||AMS 5584 Seamless/welded tube||ASTM A276 / ASME SA276|
|316 Tube||AMS 5648 Bar / wire / forging (316)||ASTM A479 / ASME A479|
|AMS 5649 Bar / wire / forging (FM)||ASTM A484 / ASME SA484|
|AMS 5653 Bar / wire / forging (316L)||ASTM F138|
|QQ-S-763||ASTM A320 Grd B8M|
|AMS-S-7720||ASTM A193 Grd B8M Cl1|
|317||QQ-S-763||ASTM A240 / ASME SA240|
|317L||ASTM A249 / ASME SA249|
|ASTM A312 / ASME SA312|
|ASTM A409 / ASME A409|
|ASTM A276 / ASME SA276|
|ASTM A478 / ASME A478|
|ASTM A479 / ASME A479|
|ASTM A314 / ASME SA314|
|ASTM A473 / ASME SA473|
|ASTM A182 / ASME A182|
|ASTM A403 / ASME SA403|
|321||AMS 5510 Sheet / strip / plate||ASTM A240 / ASME SA240|
|321 Tube||AMS 5557 Welded/seamless tube||ASTM A167 / ASME SA167|
|AMS 5559 Welded / thin wall tube||ASTM A193 Grade B8T CL1|
|AMS 5570 Seamless tube||ASTM A276 / ASME SA276|
|AMS 5576 Welded tube||ASTM A314 / ASME SA314|
|AMS 5645 Bars / wire / forging||ASTM A320 Grade B8T|
|MIL-S-6721||ASTM A479 / ASME A479|
|MIL-T-8606 Seamless tube||ASTM A484 / ASME SA484|
|MIL-T-8606 Welded tube||AISI 321|
|MIL-T-8808 Seamless tube|
|MIL-T-8808 Welded tube|
|330||AMS 5592 Sheet / strip/ plate||ASTM B511 / ASME SB511|
|RA330||AMS 5716 Bars / wire / forging||ASTM B512 / ASME SB512|
|AMS 5716 Bar Stock List||ASTM B535 / ASME SB535|
|ASTM B536 / ASME SB536|
|ASTM B710 / ASME SB710|
|ASTM B739 / ASME SB739|
|347||AMS 5512 Sheet / strip / plate||ASTM A240 / ASME SA240|
|347H||AMS 5556 Seamless/ welded tube||ASTM A167 / ASME SA167|
|347 Tube||AMS 5558 Welded /thin wall tube||ASTM A276 / ASME SA276|
|AMS 5571 Seamless tube||ASTM A314 / ASME SA314|
|AMS 5575 Welded tube||ASTM A479 / ASME A479|
|AMS 5646 Bars / wire / forging|
|AMS 5654 Bars (aircraft quality)|
|AMS 5674 Wire|
|AMS 5680 Wire|
|MIL-T-8606 Seamless tube|
|MIL-T-8606 Welded tube|
|MIL-T-8808 Seamless tube|
|MIL-T-8808 Welded tube|
|13-8Mo||AMS 5629 Bar Type 1 Vac Melt||ASTM A 564 Grade XM13|
|AMS 5629 Bar Stock List||ASME SA564 Grade XM13|
|AMS 5864 Plate||ASTM A693 / ASME SA693|
|ASTM A705 / ASME SA705|
|15-5Ph||AMS 5659 Bars / Forgings||ASTM A484 / ASME SA484|
|AMS 5826 Welding wire||ASTM A564 Grade XM12|
|AMS 5862 sheet / strip / plate|
|15-7Mo||AMS 5520 Sheet / strip / plate|
|AMS 5657 Bars / forgings||ASTM A693 Grade 632|
|17-4Ph||AMS 5604 Sheet / Strip / Plate||ASTM A564 Grade 630|
|AMS 5622 (Vac Melt) Bar||ASTM A484 / ASME SA484|
|AMS 5642 Bar||ASTM A564 / ASME SA564|
|AMS 5643 Bar||ASTM A693 / ASME SA693|
|17-7Ph||AMS 5528 Sheet / Strip / Plate||ASTM A313 / ASME SA313|
|AMS 5529 Sheet/ Strip- Cond C||ASTM A564 / ASME SA564|
|AMS 5568 Welded Tubing||ASTM A579 / ASME SA579|
|AMS 5644 Bars / Forgings||ASTM A693 / ASME SA693|
|AMS 5678 Wire||ASTM A705 / ASME SA705|
|AMS 5824 Welding wire|
|AMS 6345 Sheet / Plate, Normalised||AISI 4130|
|4130||AMS 6346 Bar Hardened & Tempered||ASTM A322|
|AMS 6350 Sheet / Plate||ASTM A331|
|AMS 6351 Sheet / Plate, spheroidised|
|AMS 6370 Bar|
|AMS 6371 Tube|
|AMS 6370/6346 Bar Stock List|
|4140 Ann||AMS 6349 Bar||ASTM S331|
|AMS 6382 Bar|
|AMS S 5626|
|AMS 6349/ 6382 Bar Stock List|
|4140 Normalised||AMS 6349||ASTM A322|
|AMS S 5626|
|4330 Mod VM N&T||AMS 6411||ASTM A646|
|AMS 6411 Bar Stock List|
|4340||AMS 6359 Sheet / strip / plate||ASTM A322|
|E4340||AMS 6409 Bars / Forgings N&T||ASTM A331|
|AMS 6414 Vac Melt Bars / Forgings||AISI E4340|
|AMS 6415 Bars / Forgings|
|AMS 6484 Bars / Forgings N&T|
|4620 Vac Melt||AMS 6294||ASTM A331|
300's - Chromium-Nickel Stainless Steel this series is austenitic, non-heat treatable, and non-magnetic.
400's - Chromium Stainless Steel this series is martensitic, heat treatable and magnetic. It also includes types, which are ferrite, non-heat treatable, and magnetic.
"L" at the end of the series number indicates low-carbon content. (Example: 304L)
"F" at the end of the series number indicates the addition of a "free-machining" element. (Example: 440F)
Other letters used at the end of the series number signify the symbol of the element added to the alloy. (Example: 440C - the C being the symbol for the Carbon additive)
There are four basic classes of stainless steels, so designated for the metallurgical conditions of the steels:
Class I: Martensitic - Heat treatable, Straight” Chromium
This class is so named for the man, Martens, who first examined metals microscopically. It is referred to as "martensitic" because of its acicular or needle-like microstructure in the hardened condition. Its chief alloying agent is chromium, found in amounts from 11.5 to 18.0%. It contains from 0.08 to 1.10% carbon. It is magnetic and responds excellently to heat treating, producing a hard and strong stainless steel.
Class II: Ferritic - Non-Heat treatable, Straight Chromium
This class name is derived from the Latin word "ferrum" meaning iron. It is so named because its microstructure is very similar to that of low-carbon iron. It also utilizes chromium as its chief alloying agent, being found in amounts from 14.0 to 27.0%. It has a very low carbon content of .08 to .20%. Due to its high chromium and low carbon content, ferritic alloys do not generally harden in high temperatures. It is a magnetic alloy, and is soft and ductile.
Class III: Austenitic - Non-Heat treatable, Chromium-Nickel
The austenitic class derives its name from Roberts-Austen who first observed its characteristic banded grain structure. Its chief alloys are: chromium, found in amounts from 16.0 to 26.0%; and a appreciable nickel content from 6.0 to 22.0%. This alloy cannot be heat treated, but responds excellently to cold working. It is generally non-magnetic. In the annealed condition, this alloy is tough, strong, and extremely ductile. Austenite itself is soft and tough and remains ductile even at extreme low temperatures.
Class IV: Precipitation-Hardening
This is a relatively new class metallurgists have deemed necessary to group separately because of its increasing popularity. These alloys have low hardening temperatures that produce precipitation hardening. This capability averts problems such as warping, cracking, and scaling. They can be hardened by simple heat treatments, require no stress-relief treatment and are available in all forms. These grades are easily fabricated, and are corrosion resistant without added treatment. They are also known for their high strength. An American Iron and Steel Institute (AISI) Type designation has not been issued these grades, as they are patented proprietary.
These alloys contain only approximately .03% carbon, which is low enough to permit elimination of carbide precipitation during welding. These grades are not generally recommended for high-temperature utilization.
Aluminum (Al) - acts as an active degasifier and deoxidizer. Controls inherent grain size.
Bismuth (Si) - acts to improve machinability.
Boron (B) - improves hardenability and increases depth of hardening. Usually found in amounts of .0005 to .003%.
Carbon (C) - improves hardenability, and increases tensile strength and response to heat treatment when added in amounts of 0.8 to 0.9%. If amount is further increased, heat and cold workability would greatly decrease, and the alloy would begin to exhibit the characteristics of cast iron.
Chromium (Cr) - gives stainless steel its stainless quality. Increases response to heat treatments and depth of hardness. In combination with nickel, greatly increases corrosion and oxidation resistance. Also increases toughness, tensile strength, and resistance to wear.
Cobalt (Co) - increases strength and hardenability of alloy. Improves effectiveness of other elements.
Columbium (Cb) - increases immunity to carbide precipitation and inter-granular corrosion.
Copper (Cu) - increases corrosion resistance and improves tensile and yield strengths without loss of ductility.
Iron (Fe) - this is the basic element of steel. Iron by itself lacks strength and does not respond to heat treatment; it is soft and ductile.
Lead (Pb) - greatly improves machinability in quantities of .15 to .35%.
Manganese (Mn) - normally present in all steel. Increases strength, hardness and response to heat treatment in amounts of .5 to 15%. It acts as a degasifier and deoxidizer, and increases the alloy's resistance to wear. In combination with sulfur, improves forgeability.
Molybdenum (Me) - increases strength, hardness penetration, and machinability. Aids in resisting softening at high temperatures, and improves resistance to corrosion.
Nickel (Ni) - in amounts of 1.0 to 35% improves the strength and impact resistance without loss of ductility. Increases resistance to corrosion, but decreases work hardening. Improves machinability and fabricability.
Nitrogen (N) - can serve as a substitute for a portion of nickel in alloys. Improves machinability by producing a fine chip.
Phosphorus (P) - increases yield strength, hardness and machinability and greatly improves resistance to corrosion. Ductility is decreased at low temperatures.
Selenium (Se) - serves to improve machinability.
Silicon (Si) - it is a common degasifier and deoxidizer. Increases tensile strength, hardenability and forgeability. At high temperatures, resists corrosion and scaling.
Sulfur (S) - in amounts of .06 to .3%, increases machinability. It is not recommended for alloys used in hot forming. It decreases weldability and ductility.
Tantalum (Ta) - used primarily as a stabilizer. It also prevents localized carbon depletion. Tellurium (Te) - when added to leaded steels, greatly improves machinability.
Titanium (Ti) - serves to increase immunity to carbide precipitation and resistance to corrosion and oxidation.
Tungsten (W) - produces a fine, dense grain. Increases hardness in high-speed steel at high temperatures.
Vanadium (V) - increases shock resistance, strength, and hardness. Retards grain growth even after exposure to high temperatures.
No. 1 Finish - this finish is mainly used for applications where appearance is secondary. It is hot rolled, annealed, and pickled.
No. 2B Finish - used primarily for drawn or formed parts, this is a bright, cold rolled sheet finish.
No. 2D Finish - this finish is similar in application to the 2B Finish, but is a dull, cold rolled sheet finish.
No. 3 Polish - a 100 grit abrasive belt is used here to produce a ground surface. This polish is a standard mill finish.
No. 4 Polish - a 150 grit abrasive belt is used here to produce a bright, highly polished surface. This process offers a finish that is not only beautiful, but is exceptionally corrosion resistant and easy to clean.
No. 6 Polish - a Tampico brush is used here for a contrasting trim and softness of appearance.
No. 7 Polish - this finish is the most highly reflective, having an extremely highly polished surface.
This grade is an austenitic stainless steel manufactured by-the electric furnace process. Its chromium and nickel content are lower than most other grades, offering the advantage of a high work-hardening rate which combines cold-worked high strength with good ductility. Tensile strength and hardness increase rapidly when the metal is cold rolled, cold drawn, or worked at room temperature. The standards of the aircraft industry are met by requiring adequate discard to be extracted from each ingot. Its application is indicated where low cost is desired and high corrosion resistance is not a primary concern.
Type 301 finds its primary usage in products necessitating great strength, but where working at elevated temperatures is not required. Used extensively in aircraft components, truck components and bodies, decorative applications, and etc.
Does not possess as high a degree of corrosion resistance as Type 302, but does remain unaffected by most normal atmospheric conditions.
Type 302 is the fundamental alloy of the austenitic class. It is commonly known as "18-8": 18% chromium; 8% nickel; and is the most commonly used of all the stainless grades, Type 302 is non-heat treatable, but cold-working considerably increases both its hardness and tensile strength. Type 302 in the cold state offers great versatility of workability because of its toughness and ductility and can be rigorously spun, rolled, drawn or machined. It offers outstanding weldability. It is extremely resistant to corrosion, and retains an untarnished silvery surface. It is also resistant to heat oxidation at temperatures up to 1500° F. It is non-magnetic in the annealed condition. The principal drawback of Type 302 is that of sensitization-under extreme conditions, carbide precipitation may occur. Type 304 alleviates this problem by decreasing the carbon content and thereby eliminating the possibility of intergranular corrosion. This low carbon alloy is most often utilized for applications requiring welding. An Extra Low Carbon alloy, Type 304L is also available for especially severe welding applications. Type 304L has the capability to avert any detrimental precipitation in the extreme 800° F. to 1650° F. range.
Both types are extremely popular in the food and dairy industries and for use in pharmaceutical equipment. It is exceedingly useful in applications where good mechanical properties and corrosion resistance are essential. It is highly desirable for products such as instrumentation where non-magnetism is fundamental. These grades are available in a wide range of forms and finishes.
Types 302, 304 and 304L exhibit good corrosion resistant qualities, particularly those corrosions caused by atmospheric conditions or chemicals. They lose some resistance at temperatures of about 750° F. to 1500° F. due to carbide precipitation. Type 304L however, has excellent corrosion resistant capabilities within this temperature range because of its low carbon content. Maximum corrosion resistance in all these grades can be achieved by annealing.
Types 303S and 303Se are both free-machining modifications of Type 302. Sulfur or a combination of selenium and phosphorus are added to this "18-8" chromium-nickel alloy to promote chip formation in machining rather than spindly spirals. Type 303 has uniform machinability and can be machined at speeds of SAE 3120, 3145, and 4615, adapting it very well for automatic screw machine applications. Manufactured by the electric-furnace process, this is a non-heat treatable alloy, the hardness and tensile strength of which may be increased greatly by cold working. It has good corrosion resistance, and is non- magnetic in the annealed state. It concurs with the stringent requirements of the aircraft industry.
Type 303 is most commonly used in applications requiring extensive machining, and where corrosion resistance, non-magnetism, and a good surface finish is imperative. Common utilizations of this alloy include aircraft fittings, shafts, spindles, and automatic screw machine applications.
Because of the additions of sulfur or selenium, the corrosion resistance of Type 303 is slightly lower than that of the other austenitic alloys. However, annealing increases its resistance to corrosion substantially.
Type 310 is the grade of stainless steel containing the highest chromium-nickel content of all grades - 25% chromium, 20% nickel, It is chiefly known for its superior scaling and corrosion resistance and it excels all other grades in its high temperature physical properties. At extremely high temperatures, its creep strength and resistance to brittling far surpasses all other austenitic grades. In the annealed state it is non-magnetic. Type 310 is a non-heat treatable alloy produced by the electric-furnace process, which concurs with the exacting standards of the aircraft industry.
Type 310 finds primary utilization in applications requiring excellent heat and oxidation resistance and where superior strength is a must. Common applications are found in the aircraft industry for engine parts and parts requiring welding, oil refinery equipment, heat exchangers and furnace parts, etc.
This grade possesses excellent corrosion resistance and withstands scaling at temperatures up to 2000° F. Its corrosion resistance reaches a maximum in the annealed condition.
Type 316 is an electric furnace processed modification of Type 302: it contains 18% chromium; 8% nickel, and; 2-3% molybdenum. This addition of molybdenum increases both the corrosion resistance and the high temperature strength of this alloy. The most outstanding advantage of this addition is the increased corrosion resistance to reducing acids and pitting or pin hole corrosion. In general, Type 316 is known as the major all-around corrosion resistant austenitic stainless steel available. Under extremely elevated temperatures, Type 31 6 proves itself to possess remarkable creep and rupture strength, This non-heat treatable, non-magnetic alloy possesses excellent cold forming and drawing properties, making it suitable for a wide range of applications. Type 316L is an extra low carbon modification of Type 316 recommended for use during welding operations. The low carbon factor eliminates the possibility of harmful carbide precipitation in the 800° F. to 1500° F. range.
Type 316 and Type 316L find their greatest use in the chemical, textile, paper, pharmaceutical, and photographic industries because of their excellent resistance to chemical corrosion. They also find use where the combination of corrosion resistance and extremely high strength at elevated temperatures is necessary.
Type 316 is known to be more resistant to atmospheric and chemical corrosion than any other grade of the stainless steels. Maximum corrosion resistance may be obtained by fully annealing this alloy. If the application calls for welding, Type 316L should be used as it is highly resistant to carbide precipitation and intergranular corrosion. Which usually occurs at high temperatures.
Type 321 is an electric-furnace processed austenitic stainless steel. It is non-heat treatable and non-magnetic in the annealed condition. This alloy contains 18% chromium, 8% nickel and a substantial addition of titanium. The titanium forms insoluble and stable carbide, which ties up all the carbon in the alloy and therefore prevents it from precipitating as chromium carbides. This leaves the chromium in solution to resist corrosion to a very high degree. This is extremely beneficial in applications of temperatures ranging from 800° F, to 1600° F., as it eliminates the necessity for re-annealing after fabrication.
Type 321 is used principally for applications involving welding or sustained elevated temperature operations where re-annealing is not practical, It is used extensively in the aircraft and missile industries for engine parts, heat exchangers, exhaust stacks, rocket engines, manifolds, and etc.
This alloy is extremely resistant to intergranular corrosion and has very good corrosion resistance in weld areas. It has slightly less corrosion resistance to atmospheric conditions than Type 302 or Type 304 in the annealed condition.
Type 347 is a non-heat treatable, austenitic, electric furnace processed grade of stainless steel very similar in composition to Type 321. The major difference between Type 321 and Type 347 is that rather than having an addition of titanium, Type 347 has columbium added to it. Tantalum occurs in nature in conjunction with columbium and therefore it may be said that both are additives to this alloy. Type 347 can withstand more severely elevated temperatures than Type 321, as the resulting columbium carbide is more stable and insoluble than the titanium carbide. The only drawback in the use of Type 347 as opposed to Type 321 is that it is not recommended for use in radioactive services as radioactive tantalum has a much longer half-life than columbium. It is non-magnetic in the annealed state.
Type 347 is mainly used where corrosion resistance and sustained operations at temperatures between 800° F. and 1600° F. is of the utmost importance. It is also a superior grade for use on heavy welded objects, which cannot be re-annealed. It finds its principal applications in aircraft and missile engines, high temperature equipment in chemical industry, manifolds, furnace and blower parts, and etc.
Resistance to intergranular corrosion and carbide precipitation is excellent with this grade. Its general atmospheric corrosion resistance is good, being similar to that of Type 302.
Type 410 is a magnetic, martensitic, heat treatable alloy that is 12% straight chromium. It has excellent creep strength and corrosion resistance. Heat treatments may be applied to develop a very wide range of mechanical properties and hardness. It is popularly used for parts operating at temperatures up to 850° F.
Because of its high strength and versatility in heat treatment applicability, and because of its good mechanical and machining properties, Type 410 finds usage in a wide range of applications. It is used for low-cost cutlery, food industry machine parts, pump shafts, valve parts, compressor shrouds, and abrasive applications. It is not generally recommended for high-stress usage above 1200° F.
Type 410 has excellent corrosion resistance to normal atmospheric conditions discoloration or a rusty film may occur under some conditions, but destructive scaling will not occur. It reaches its maximum corrosion resistance when hardened and polished.
Type 416 is an electric furnace processed, magnetic, free-machining grade of the martensitic stainless steels. It is a modification of Type 410 with approximately .30% sulfur added for excellent machinability. Like Type 410, it has an exceptionally wide range of mechanical properties obtainable through heat treating, This grade of stainless steel has the highest machinability of all grades now developed, and can often be used in the "as machined" condition without heat treatment.
Because of its excellent machinability, corrosion resistance, and high strength. Type 416 is normally used for applications requiring extensive or high speed machining such as: nuts and bolts; pump parts; screw machine parts; and etc.
This grade has very good overall corrosion resistance to normal atmospheric conditions, mildly corrosive chemicals, and acidic or alkaline water. Hardening and polishing increases its corrosion to its maximal level. Resists scaling at temperatures up to approximately 1300° F.
15-5 PH is a chromium-nickel alloy containing a 5% copper additive, which permits it to be hardened by low temperature heat treatments. The high percentages of chromium and nickel give-15-5 PH excellent corrosion resistance, transverse toughness and forgeability. This alloy is produced by the vacuum arc re-melt method, which enhances ductility and toughness. 15-5 PH has excellent physical and mechanical properties and may be deep drawn, forged, welded and formed.
15-5 PH is very similar both in composition and application to 17-7 PH. Because of its high strength and excellent corrosion resistance, 15-5 PH finds extensive use in the aircraft and missile industries for parts ranging from instrumentation to landing gear components.
15-5 PH has excellent overall corrosion resistance, being comparable to that of Type 304 in most media. Heat-treating increases to the highest degree its resistance to stress-corrosion cracking.
17-4 PH is a chromium-nickel alloy that has a 4% copper additive, which enables it to be hardened by very low-temperature heat treatments known as precipitation hardening. The high percentages of chromium and nickel give this alloy excellent corrosion resistance, physical properties, and a high level of strength at temperatures up to 800° F. The major advantage of low temperature heat treatments is the elimination of distortion and scaling. 17-4 PH has excellent mechanical properties and may easily be welded, deep drawn, forged, and severely formed.
This alloy is excellently suited for applications requiring high strength, good corrosion resistance and good resistance to seizing and galling. 17-4 PH finds extensive use in the aircraft and missile fields, for motor shafts, instrument parts, gears, and etc.
The corrosion resistance of 17-4 PH is slightly less-than-the superior resistance of the chromium-nickel grades, but is somewhat higher than the straight chromium grades. It possesses very good corrosion resistance against all atmospheric conditions. Finish and heat treatment affect the level of corrosion resistance beneficially.
17-7 PH contains 17% chromium, 7% nickel and 1% aluminum. It is a precipitation hardening steel capable of reaching very high strength and hardness without any loss of corrosion resistance. Surface scaling and distortion in heat treatment is eliminated by its ability to be treated at very low temperatures. In the annealed condition, it has excellent ductility and machineability. It retains remarkable mechanical and physical properties at temperatures up to 800° F.
17-7 PH is used for applications necessitating high strength, good corrosion resistance and good mechanical properties at elevated temperatures. Characteristic applications include surgical instruments, springs, bearings, aircraft panels, and etc.
The corrosion resistance of 17-7 PH is superior to the straight chromium grades. Surface finish and aged heat treatments tend to have a beneficial effect upon the corrosion resistance of 17-7 PH.