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of Stainless Steel for Material Selection Physical Austenitic Ferritic Martensitic Precipitation Mechanical
Transfer Shapes and Forming Forming Fastening Protection Cleaning A
Corrosion B
Figures Specialty Steel lndustry of North
America SSINA and the it represents have made
every effort to ensure that the in this handbook is However neither the SSlNA nor
its member companies warrants the
accuracy of the information contained in
this handbook or its suitability for any
general and specific use and assumes
no liability or of any kind in
connection with the use of this reader is advised that the herein should not be used or
relied on for any specific or without first advice
Stainless steels are ironbase alloys containing 105 or They have been used for many industrial and consumer applications for over a half century
are being marketed a number of stainless steels by the American lron and Steel lnstitute AISI as Also commercially available are proprietary
stainless steels
with special See Appendix A
With so many stainless steels from which to choose have a ready source of information on the of these useful alloys To fill this need the Committee
Stainless Steel Producers initially prepared this booklet The data
was reviewed and updated by the Specialty Steel lndustry of North
America SSINA Written especially for design engineers it presents
an overview of a broad range of stainless steels both standard their compositions their properties their their use More detailed information on
the standard grades
with special emphasis on the manufacture finish designations and weight tolerances of the product forms in which
they are marketed is contained in the lron and Steel Society of the
AlME the American lnstitute of Mining Metallurgical and Steel Products Manual Stainless and Heat The AlME undertook the publication updating and
sale of
this manual after the AlSl discontinued publication in 1986
Reference is often made to stainless steel in the singular sense as
if it were one material Actually there are well over 100 stainless steel
alloys Three general are used to identify They are 1 Metallurgical Structure 2 The AlSl namely 200 300 and 400 Series numbers 3 The System which
was developed by American Society for
Testing Materials ASTM and Society of Automotive Engineers SAE
to apply to all commerical metals and alloys
There are also a number of grades known by common names that
resemble AlSl designations and these are recognized by ASTM
These common names which are neither trademarks nor with a single producer are shown and identified in the
tables These common nonAISI names also appear in the Nearly all stainless steels used in North America have
UNS On the following pages there is a description of these 15 list stainless steels according to metallurgical ferritic martensitic
precipitation hardening and duplex
3050 K Street NW
Washington DC 20007
TEL 202 3428630 or 800 9820355
FAX 202 3428631
Austenitic stainless steels Table 1 Ferritic stainless steels Table 2 are chromium and nickel are 400 Series types that
steels Table 4 are as 300 Series types Alloys cannot be hardened by heat treatment types some containing other chromium nickel
and and only moderately hardened by cold elements such as copper or are identified as 200 Series working They are
magnetic have good They can be hardened by The stainless steels in the austenitic ductility and resistance to corrosion and treating and
aging to high have different compositions and oxidation Type 430 is the but many common character stainless of the ferritic They
can be hardened by cold Table 4
working but not by heat treatment In the PRECIPITATION condition all are essentially
Table 2 STAINLESS although some may FERRITIC STAINLESS STEELS UNS
UNS
become slightly magnetic by cold Equivalent Equivalent S13800 They have excellent
corrosion TYPE UNS TYPE UNS S15500 unusually good formability 405 S40500
430FSe S43023
and increase in strength as a result of 409 S40900 434 S43400
cold work Duplex stainless steels Table 5 have
429 S42900 436 S43600 an annealed structure which is typically
Type 304 sometimes referred to as 430 S43000 442 S44200
188 stainless is the most widely used about equal parts of austenite and ferrite
430F S43020 446 S44600
alloy of the austenitic group It has a Although not formally defined it is
nominal composition of 18 chromium generally accepted that the lesser phase
and 8 nickel will be at least 30 by volume
Martensitic stainless steels Table 3 Duplex stainless steels offer several
are 400 Series types advantages over the common austenitic
that are hardenable by heat treatment stainless steels The duplex grades are
Table 1 They are magnetic They resist corrosion highly resistant to chloride stress
AUSTENITIC in mild environments They have fairly corrosion cracking have excellent pitting
STAINLESS STEELS good ductility and some can be heat and crevice corrosion resistance and
Equivalent Equivalent treated to tensile strengths exceeding exhibit about twice the yield strength as
TYPE UNS TYPE UNS 200000 psi 1379 MPa conventional grades Type 329 and 2205
201 S20100 310 S31000 Type 410 is the alloy are typical alloys
202 S20200 310S S31008 of the martensitic group With respect to the Unified Numbering
205 S20500 314 S31400 System the UNS designations are
301 S30100 316 S31600 shown alongside each AlSl type number
302 S30200 316L S31603 Table 3 in Tables 15 except for four stainless
302B S30215 316F S31620 MARTENSITIC steels see Table 4 for which UNS
303 S30300 316N S31651
STAINLESS STEELS designations only are listed
303Se S30323 317 S31700
304 S30400 317L S31703 Equivalent Equivalent
TYPE UNS TYPE UNS
304L S30403 317LMN S31726 Table 5
302HQ S30430 321 S32100 403 S40300 420F S42020
304N S30451 330 NO8330 410 S41000 422 S42200 DUPLEX
305 S30500 347 S34700 414 S41400 431 S43100 STAINLESS STEELS
308 S30800 348 S34800 416 S41600 440A S44002 TypeName UNS
309 S30900 384 S38400 416Se S41623 440B S44003 329 S32900
309S S30908 420 S42000 440C S44004 2205 S31803
2205 hi N 304 202
General N Mn
Purpose partially
replaces
302B 205 201
Si added N Mn N Mn
to increase partially partially
scaling replaces replaces
resistance Ni Ni
317 316 309S 308 305 303 301
More Mo added 309S Higher
302 Ni increased S added Cr Ni
Mo Cr Higher C
to increase CR Ni CR Ni to lower to improve lowered to
added for for increased
better corrosion increased used work machining increase
strength
corrosion resistance for high primarily hardening work
resistance temperature for welding 317L
316L 310S 347 321 304L 384 303Se
C reduced C reduced 310S Cb Ti added C reduced More Ni Se added
for for Same as added to prevent even to lower for better
welding welding 309 only to prevent carbide further work machined
more so carbide precip hardening surfaces
precip
317LMN 316N 314 348 304N S30430 316F
Mo added N added Si increased Ta Co N added Cu added SP
N added to for highest restricted to increase to improve increased
increase heat for nuclear strength cold to improve
strength resistance applications working 330
Ni added
to resist
thermal Al Aluminum P Phosphorus
shock C Carbon S Sulfur
Cr Chromium Se Selenium
Cb Columbium Si Silicon
Co Cobalt Ta Tantalum
Cu Copper Ti Titanium
Mn Manganese V Vanadium
Mo Molybdenum W Tungsten
N Nitrogen SCC Stress Corrosion
Ni Nickel Cracking
General
Purpose
405 409 434
446 442 429 Lower Cr Lower Cr
430F Mo added
Cr Cr Slightly AI added PS
Primarily for improved
increased increased Less Cr to prevent added for
used for corrosion
to improve to improve for better hardening improved
when colled automotive resistance
scaling scaling weldability machining
from elevated exhaust in auto trim
resistance resistance
430F Se 436
Se added Mo Cb added
for corrosion
for better
heat
machined resistance
surfaces improved
General
Purpose
431 414 403 420 416 440C
Cr increased Ni added Select Increased PS C increased
Ni added for better quality C to increased for highest
for corrosion
resistance corrosion for turbines improve to improve hardness
Good resistance and highly mechanical machining Cr increased
Mechan stressed properties for corrosion
Properties parts 422 416
Se 440B
Strength Se added C decreased
toughness to for better slightly to
1200F via machined improve
addition of surface toughness
Mo V W
420F 440A
Al Aluminum P Phosphorus PS Same as
C Carbon S Sulfur increased 440B only
Cr Chromium Se Selenium to improve more so
Cb Columbium Si Silicon machining
Co Cobalt Ta Tantalum
Cu Copper Ti Titanium
Mn Manganese V Vanadium
Mo Molybdenum W Tungsten
N Nitrogen SCC Stress Corrosion
Ni Nickel FOR SELECTION Material Selection The above comments on the
suitability
Stainless steels are engineering Many variables characterize a of stainless steels in various with good corrosion
resistance corrosive environment ie chemicals are based on a long history of and fabrication and their atmospheric
application but they are intended only as
They can readily meet a wide range of conditions temperature time so it is guidelines Small differences in criteria load service life
low difficult to select which alloy to use content and temperature such as etc Selecting the proper without knowing the exact
nature of the occur during processing can steel essentially means environment However there are corrosion rates The
magnitude can be
weighing four elements In order of guidelines considerable as suggested by Figures 2
importance they are Type 304 serves a wide range of and 3 Figure 2 shows small quantities of
1 Corrosion or Heat Resistance applications It withstands ordinary hydrofluoric and sulfuric acids having a
the primary reason for specifying rusting in architecture it is resistant to serious effect on Type 316 stainless The specifier needs
to know food processing environments except in an environment of 25 nature of the environment and the possibly for
conditions acid and Figure 3 shows effects of
degree of corrosion or heat resistance involving high acid and chloride temperature on Types 304 and 316 in
required contents it resists organic chemicals very concentrated sulfuric acid
2 Mechanical Properties with dyestuffs and a wide variety of inorganic Service tests are most reliable in
particular emphasis on strength at room chemicals Type 304 L low carbon determining optimum material and
elevated or low temperature Generally resists nitric acid well and sulfuric acids ASTM G 4 is a recommended the combination of corrosion
at moderate temperature and for carrying out such tests Tests and strength is the basis for It is used extensively
for cover conditions both during storage of liquified gases equipment for and shutdown For instance
sulfuric
3 Fabrication Operations and use at cryogenic temperatures 304N sulfurous and polythionic acid conden
how the product is to be made is a third appliances and other consumer sates formed in some processes during
level This includes forging products kitchen equipment hospital shutdowns may be more corrosive forming welding etc
equipment and waste the process stream itself Tests should
4 Total Cost in considering total water treatment be conducted under the worst it is appropriate to consider not
only Type 316 contains slightly more nickel conditions and production costs but the than Type 304 and 23 molybdenum
Several standard reference volumes
life cycle cost including the costsaving giving it better resistance to corrosion discuss corrosion and corrosion of a product
than Type 304 especially in chloride including Uhligs Corrosion a long life expectancy environments that tend to cause
pitting LaQue and Copsons Corrosion Resistance
Type 316 was developed for use in Of Metals and Alloys Fontana and
CORROSION RESISTANCE sulfite pulp mills because it resists Greens Corrosion Engineering A Guide
Chromium is the alloying element that sulfuric acid compounds Its use has to Corrosion Resistance by to stainless steels their
corrosion been broadened however to handling Molybdenum Company the qualities by combining with many chemicals in the process
Data Survey by the National to form a thin invisible chromium industries of Corrosion Engineers
and the ASM
oxide protective film on the surface Type 317 contains 34 molybdenum Metals Handbook Corrosion data
Figure 1 Figures are shown in Appendix higher levels are also available in this and Because the passive film is such an series
and more chromium than Type practices relating to stainless steels are
important factor there are precautions 316 for even better resistance to pitting also issued by ASTM Stainless steels
which must be observed in designing and crevice corrosion resist corrosion in a broad range of
stainless steel equipment in Type 430 has lower alloy content than conditions but they are not immune the equipment and in
Type 304 and is used for highly polished every environment For example and use of the equipment to trim applications in mild
atmospheres It steels perform poorly in destroying or disturbing the film is also used in nitric acid and food environments such
as 50 sulfuric
In the event that the protective passive processing and hydrochloric acids at elevated
film is disturbed or even destroyed it Type 410 has the lowest alloy content temperatures The corrosive attack
will in the presence of oxygen in the of the three stainless experienced is a breakdown of reform and continue to give steels
and is selected for highly stressed protective film over the entire metal protection parts needing the combination of
Such of stainless
The protective film is stable and strength and corrosion resistance such steels are rare and are usually in normal atmospheric or
mild as fasteners Type 410 resists corrosion The types of attack which are more environments but can be in mild
atmospheres steam and many to be of concern are pitting by higher chromium and by mild chemical environments
attack stress corrosion cracking nickel and other alloying 2205 may have advantages over Type intergranular corrosion which are
elements Chromium improves film 304 and 316 since it is highly resistant to discussed in Appendix A
stability molybdenum and chromium chloride stress corrosion cracking and is
increase resistance to chloride about twice as and nickel improves in some acid environments Table 6 lists the relative
corrosion
resistance of the AlSl standard numbered
stainless steels in seven broad categories
of corrosive environments Table 7 details
more specific environments in which
various grades are used such as acids
bases organics and
5
Table 6
Relative Corrosion Resistance of AISI Stainless Steels 1
Mild Atmos Atmospheric Chemical
TYPE UNS pheric and Number Number Fresh Water
Industrial Marine Miild Oxidizing Reducing
201 S20100 x x x x x
202 S20200 x x x x x
205 S20500 x x x x x
301 S30100 x x x x x
302 S30200 x x x x x
302B S30215 x x x x x
303 S30300 x x x
303 Se S30323 x x x x
304 S30400 x x x x x
304L S30403 x x x x x
S30430 x x x x x
304N S30451 x x x x x
305 S30500 x x x x x
308 S30800 x x x x x
309 S30900 x x x x x
309S S30908 x x x x x
310 S31000 x x x x x
310S S31008 x x x x x
314 S31400 x x x x x
316 S31600 x x x x x x
316F S31620 x x x x x x
316L S31603 x x x x x x
316N S31651 x x x x x x
317 S31700 x x x x x x
317L S31703 x x x x x
321 S32100 x x x x x
329 S32900 x x x x x x
330 N08330 x x x x x x
347 S34700 x x x x x
348 S34800 x x x x x
384 S38400 x x x x x
403 S40300 x x
405 S40500 x x
409 S40900 x x
410 S41000 x x
414 S41400 x x
416 S41600 x
416 Se S41623 x
420 S42000 x
420F S42020 x
422 S42200 x
429 S42900 x x x x
430 S43000 x x x x
430F S43020 x x x
430F Se S43023 x x x
431 S43100 x x x x
434 S43400 x x x x x
436 S43600 x x x x x
440A S44002 x x
440B S44003 x
440C S44004 x
442 S44200 x x x x
446 S44600 x x x x x
S13800 x x x x
S15500 x x x x x
S17400 x x x x x
S17700 x x x x x
The X notations indicate that a specific stainless steel type may be considered the member companies When selecting a stainless steel for any
corrosive
as resistant to the corrosive environment categories environment it is always best to consult with a corrosion engineer
and if possible
conduct tests in the environment involved under actual operating conditions
This list is suggested as a guideline only and does not suggest or imply a
warranty on the part of the Specialty Steel Industry of the United States or any 7
Where Different Grades Are Used 15
Environment Grades Environment Grades
Acids
Hydrochloric acid Stainless generally is not recommended except when solutions are very dilute and at room Mixed acids There is usually
no appreciable attack on Type 304 or 316 as long as sufficient nitric acid is present
Nitric acid Type 304L or 430 is used
Phosphoric acid Type 304 is satisfactory for storing cold phosphoric acid up to 85 and for handling up to 5 in some unit
processes of manufacture Type 316 is more resistant and is generally used for storing and manufacture if the fluorine
content is not too high Type 317 is somewhat more resistant then Type 316 At up to 85 the metal
temperature should not exceed 212 F 100 C with Type 316 and slightly higher with Type 317 Oxidizing ions inhibit
attack and other inhibitors such as arsenic may be added
Sulfuric acid Type 304 can be used at room temperature for over 80 Type 316 can be used in contact with sulfuric
acid up to 10 at temperatures up to 120 F 50 C if the solutions are aerated the attack is greater in airfree solutions
Type 317 may be used at temperatures as high as 150 F 65 C with up to 5 The presence of other
materials may markedly change the corrosion rate As little as 500 to 2000 ppm of cupric ions make it possible to use
Type 304 in hot solutions of moderate Other additives may have the opposite effect
Sulfurous acid Type 304 may be subject to pitting particularly if some sulfuric acid is present Type 316 is usable at moderate
and Bases
Ammonium hydroxide Steels in the 300 series generally have good corrosion resistance at virtually all and temperatures in
sodium hydroxide weak bases such as ammonium hydroxide In stronger bases such as sodium hydroxide there may be some attack
caustic solutions cracking or etching in more concentrated solutions and at higher temperatures Commercial purity caustic solutions may
contain chlorides which will accentuate any attack and may cause pitting of Type 316 as well Type 304
Organics
Acetic acid Acetic acid is seldom pure in chemical plants but generally includes numerous and varied minor constituents Type 304 is
used for a wide variety of equipment including stills base heaters holding tanks heat exchangers pipelines valves and
pumps for up to 99 at temperatures up to about 120 F 50 C Type 304 is also satisfactory for contact
with 100 acetic acid vapors and if small amounts of turbidity or color pickup can be tolerated for room
temperature storage of glacial acetic acid Types 316 and 317 have the broadest range of usefulness especially if formic
acid is also present or if solutions are unaerated Type 316 is used for fractionating equipment for 30 to 99
where Type 304 cannot be used for storage vessels pumps and process equipment handling glacial
acetic acid which would be discolored by Type 304 Type 316 is likewise applicable for parts having temperatures above
120 F 50 C for dilute vapors and high pressures Type 317 has somewhat greater corrosion resistance than Type 316
under severely corrosive conditions None of the stainless steels has adequate corrosion resistance to glacial acetic acid
at the boiling temperature or at superheated vapor Aldehydes Type 304 is generally Amines Type 316 is usually preferred
to Type 304
Cellulose acetate Type 304 is satisfactory for low temperatures but Type 316 or Type 317 is needed for high Citric formic and Type 304 is
generally acceptable at moderate temperatures but Type 316 is resistant to all at
tartaric acids temperatures up to boiling
Esters From the corrosion standpoint esters are comparable with organic acids
Fatty acids Up at about 300 F 150 C Type 304 is resistant to fats and fatty acids but Type 316 is needed at 300 to 500 F 150 to
260 C and Type 317 at higher Paint vehicles Type 316 may be needed if exact color and lack of contamination are important
Phthalic anhydride Type 316 is usually used for reactors fractionating columns traps baffles caps and piping
Soaps Type 304 is used for parts such as spray towers but Type 316 may be preferred for spray nozzles and flakedrying belts
to miniimize offcolor products
Synthetic detergents Type 316 is used for preheat piping pumps and reactors in catalytic hydrogenation of fatty acids to give salts of
sulfonated high molecular alcohols
Tall oil pump and Type 304 has only limited usage in talloil distillation service streams can be handled by Type 316L
paper industry with a minimum molybdenum content of 275 Type 316 can also be used in the more corrosive highfatty acid streams
at temperatures up to 475F 245 C but Type 317 will probably be required at higher Tar Tar distillation equipment is almost all
Type 316 because coal tar has a high chloride content Type 304 does not
have adequate resistance to pitting
Urea Type 316L is generally required
Type 316 is usually selected for all parts in contact with the product because of its inherent corrosion resistance and
greater assurance of product purity
010 AND PHYSICAL New Design Specification of two notations in this Room Temperature
Until recently design engineers 1 The maximum thickness for Type
wanting to use austenitic stainless steels 409 ferritic stainless used in the Stainless Steels structurally had to improvise
due to the is limited to 015 inches
The austenitic stainless steels cannot lack of an appropriate design 2 The maximum thickness for Type 430
be hardened by heat treatment but can The familiar American lnstitute for Steel and 439 ferritic stainless steels is limited
be strengthened by cold work and thus Construction and AlSl design to 0125 inches
they exhibit a wide range of mechanical for carbon steel design do not apply to This is in recognition of concerns At room
temperature the design of stainless steel members the ductile to brittle stainless steels exhibit yield because of
differences in strength temperature of the ferritic stainless between 30 and 200 ksi 207 properties modulus of elasticity and the
in structural application It should be
1379 MPa depending on composition shape of the stress strain curve Figure noted that these alloys have been used
and amount of cold work They also 17 shows that there is no welldefined in plate thickness for other good ductility and toughness
yield point for stainless steel Generally toughness in the annealed
even at high strengths and this good condition decreases as the and toughness is retained at
content increases Molybdenum temperatures The chemical Table 9
to increase ductility whereas and nominal mechanical TYPICAL ENDURANCE LIMITS OF tends to decrease
ductility of annealed austenitic ANNEALED stainless steels can be used for steels are given in Table 8
STAINLESS STEEL SHEET 2 applications as noted above as well as
The difference in effect of cold work of AISI Endurance such traditional applications as kitchen
Types 301 and 304 is indicated by the Type limit ksi MPa sinks and automotive appliance and
stress strain diagrams in Figure 11 301 35 241 luggage trim which require good
Carbon and nitrogen contents affect 302 34 234 resistance to corrosion and bright highly
yield strength as shown by the 303 35 241 polished among Types 304 304L 304
35 241 When compared to lowcarbon steels
and 304N The effect of manganese and 316 39 269 such as SAE 1010 the standard on strength can be seen by
321 38 262 AlSl ferritic stainless steels such as
comparing Types 301 and 302 against 347 39 269 Type 430 exhibit somewhat higher yield
Types 201 and 202 and tensile strengths and low elongations
Figures 12 13 14 and 15 illustrate Thus they are not as formable as the
other effects of small composition Now the American Society of Civil lowcarbon steels The proprietary For example at a given
Engineers ASCE in conjunction with stainless steels on the other hand with
amount of cold work Types 202 and 301 the SSINA has prepared a standard lower carbon levels have higher yield and tensile
strengths for the ductility and formability comparable with
than Types 305 and 310 Design of ColdFormed Stainless Steel that of lowcarbon steels Because of the
Austenitic stainless steels which can Structural Members This standard higher strength levels the ferritic stainless
be cold worked to high tensile and yield covers four types of austenitic stainless steels require slightly more power to while retaining
good ductility steel specifically Types 201 301 304 Micro cleanliness is important to good
and toughness meet a wide range of and 316 and three types of ferritic formability of the ferritic types criteria For example
sheet and stainless steels See Ferritic section inclusions can act as initiation sites for
strip of austenitic steels usually Types below This standard requires the use of cracks during forming
301 and 201 are produced in the structural quality stainless steel as Type 405 stainless is used where the
following tempers defined in general by the provisions of annealed mechanical properties and
the American Society for Testing and corrosion resistance of Type 410 are
Tensile Yield Materials ASTM satisfactory but when better weldability is
Strength Strength Some of the physical properties of desired Type 430 is used for formed
Temper Minimum Minimum austenitic stainless steels are similar to products such as sinks and decorative
ksi MPa ksi MPa those of the martensitic and ferritic trim Physical properties of Type 430 are
stainless steels The modulus of elasticity shown in Table 10 Types 434 and 436
14Hard 125 862 75 517
12Hard 150 1034 110 758
for example is 28 x 106 psi 193 GPa are used when better 175 1207 135 931 and density is 029 Ib per cu in 8060
resistance is required and for 185 1276 140 965 Kgm3 The physical properties of severe stretching
annealed Type 304 are shown in Table 10 For fasteners and other machined parts
In structural applications the Types 430F and 430F Se are often and fatigue strength of
these
Ferritic Stainless Steels
Ferritic stainless steels contain approxi the latter being specified when forming is
steels are important At room required in addition to machining
mately 12 chromium and up in the annealed condition Types 442 and 446 are heat resisting
chemical composition of the standard
the austenitic steels exhibit Charpy grades
grades are shown in Table 11 along with
Vnotch energy absorption values in Type 409 which has the lowest
nominal mechanical properties Also
excess of 100 ftlb The effect of cold chromium content of the stainless steels
several proprietary grades see Type 301 on toughness is is widely used for automotive
exhaust
A have achieved relatively in Figure 16 This shows Type systems
commercial to have good toughness even after
Three ferritic stainless steels namely
cold rolling to high tensile strengths
Types 409 430 and 439 are included in
Fatigue or endurance limits in bending
the ASCE for the Design of
of austenitic stainless steels in the
ColdFormed Stainless Steel condition shown in Table 9 are
Members Designers should be aware
about onehalf the tensile strength
Stainless Steels lmpact tests on martensitic grades The densities of the martensitic
The martensitic grades are so named show that toughness tends to decrease stainless steels about 028 Ib per cu
because when heated above their critical with increasing hardness Highstrength in 7780 Kgm3 are slightly lower 1600F or 870C and
cooled highcarbon Type 440A exhibits lower those of the carbon and alloy steels As
rapidly a metallurgical structure known as toughness than Type 410 Nickel a result they have excellent is obtained In the
hardened increases toughness and Type 414 has damping the steel has very high strength a higher level of toughness than Type
The martensitic stainless steels are
and hardness but to obtain optimum 410 at the same strength level generally selected for moderate resistance ductility
and impact Martensitic grades exhibit a ductile to corrosion relatively high strength and
strength the steel is given a stress brittle transition temperature at which good fatigue properties after suitable or tempering
treatment usually notch ductility drops very suddenly The treatment Type 410 is used for fasteners
in the range 300700F 149371C transition temperature is near room machinery parts and press plates If
Tables 12 13 and 14 give the chemical temperature and at low temperature greater hardenability or higher and mechanical properties
about 300F 184C they become very is required Type 414 may be used and
of martensitic grades in the annealed and brittle as shown by the data in Figure 19 for better Types 416 or
hardened conditions This effect depends on composition 416 Se are used Springs flatware knife
The martensitic stainless steels fall into heat treatment and other variables blades and hand tools are often made
two main groups that are associated with Clearly if notch ductility is critical at from Type 420 while Type 431 is ranges of mechanical
properties room temperature or below and the used for aircraft parts requiring high compositions with a maximum
steel is to be used in the hardened strength and resistance to shock of about Rockwell C45 and the condition careful evaluation
is required consumes most of Types 440A and compositions which can If the material is to be used much below whereas Type 440C
is frequently used for
be hardened up to Rockwell C60 The room temperature the chances are that valve parts requiring good wear hardness of both groups
in the Type 410 will Highcarbon martensitic condition is about Rockwell not be satisfactory While its notch
ductility steels are generally not The dividing line between the two is better in the annealed condition down for welded
applications although Type
groups is a carbon content of to 100F 73C another type of stainless 410 can be welded with relative 015
steel is probably more appropriate Hardening heat treatments should follow
In the lowcarbon class are Types 410 The fatigue properties of the forming operations because of the poor
416 a grade and 403 a martensitic stainless steels depend on forming qualities of the hardened grade The properties heat
treatment and design A notch in heat treatment and structure or the effect of a of these three stainless steels environment can
do more to reduce
are similar except for the better fatigue limit than alloy content or of Type 416 treatment
On the highcarbon side are Types Figure 20 gives fatigue data for Type
440A B and C 403 turbine quality stainless at three
Types 420 414 and 431 however test temperatures The samples were
do not fit into either category Type 420 smooth and polished and the
has a minimum carbon content of 015 atmosphere was air
and is usually produced to a carbon Another important property is of 0304 While it will not or wear resistance Generally the
harder
harden to such high values as the 440 the material the more resistance to
types it can be tempered without abrasion it exhibits In applications loss in corrosion resistance corrosion occurs however such
as in
Hence a combination of hardness and coal handling operations this ductility suitable for cutlery or rule may not hold because the
oxide film
plastic molds is attained is continuously removed resulting in a
Types 414 and 431 contain 125 high apparent rate
250 nickel which is enough to increase Other mechanical properties but not enough to make martensitic stainless steels such as
them austenitic at ambient temperature compressive yield shear strength are
The addition of nickel serves two purposes generally similar to those of carbon and
1 it improves corrosion resistance alloy steels at the same strength it permits a higher chromium physical and 2 it
enhances toughness of Type 410 are shown in Table 10 The
Martensitic stainless steels are subject property of most interest is modulus of
to temper embrittlement and should not elasticity The moduli of the heat treated or used in the range of stainless steels 29 x 106
psi 200 GPa
800 to 1050F 427566C if toughness is are slightly less than the modulus of
important The effect of tempering in this carbon steel 30 x 106 psi 207 GPa but
range is shown by the graph in Figure are markedly higher than the moduli of
18 Tempering is usually performed other engineering materials such as
above this temperature range aluminum 10 x 106 psi 67 GPa
Hardening 260 ksi 1793 MPa tensile can be Precipitation hardening Steels achieved
exceeding even those of steels have high strength relatively good
The principle of precipitation hardening the martensitic stainless steels while ductility and good corrosion resistance
is that a supercooled solid solution corrosion resistance is usually superior at moderate temperatures They are
solution annealed material changes its nearly equal to that of Type 304 utilized for aerospace structure on aging The stainless
Ductility is similar to components fuel tanks landing advantage is that products can corresponding martensitic grades at the covers
pump parts shafting bolts
be fabricated in the annealed condition same strength level Table 15 shows the saws knives and flexible then strengthened by a relatively
chemical composition and the nominal expansion 9001150F 482620C mechanical properties of four AlSl Physical
properties of UNS S13800 minimizing the problems standard precipitation hardening shown in Table with stainless
steels in solution treated Strength levels of up to age hardened

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The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.