ENGINEERING STEELS + ALLOYS

416 Martensitic Stainless Steel Bar

416 is a free machining basic straight chromium high hardenability martensitic stainless steel with excellent machinability, reasonable strength and corrosion resistance. Generally supplied either hardened and tempered in the tensile range 550 - 700 Mpa (condition P) Brinell range 152 - 207, or in the annealed condition with a maximum Brinell hardness of 207.Characterised by excellent machinability, non-galling and non-seizing properties due to its higher sulphur content which has the effect of lowering its corrosion resistance. It is however resistant to mild corrosive atmospheres, fresh water, steam, organic materials, many mild acids and petroleum products, coupled with reasonable strength in the hardened and tempered condition. 416 due to its excellent hardenability is capable of being through hardened up to Rc40 depending upon carbon content and section size. Small sections can be air cooled and larger sections oil quenched for maximum through hardness.Pre hardened and tempered 416 will also respond readily to nitriding achieving a typical surface hardness of over Rc65. The nitriding process however reduces the corrosion resistance and is therefore not generally recommended except for critical applications where the benefit outweighs all other considerations.

Material magnetic in all conditions.

 

Colour Code Stocked Sizes
Pink & Green
(Bar end)

Stock Sizes 12.7 to 130 mm diameter.
Bar Finish
Peeled Bar
Related Specifications
Australia AS 2837-1986 416
Germany W.Nr 1.4005 X12CrS13
Great Britain BS970 Part3 1991 416S21
BS970 1955 EN56AM
Japan JIS G4303 SuS 416
USA ASTM A582/A582M-95b 416
SAE 51416 AISI 416
UNS S41600
Chemical Composition
Min. % Max %
Carbon 0.09 0.15
Silicon 0 1.00
Manganese 0 1.50
*Nickel 0 1.00
Chromium 11.50 14.00
*Molybdenum 0 0.60
Phosphorous 0 0.0.6
Sulphur 0.15 0.35
*Nickel & Molybdenum additional option
Mechanical Property Requirements For Material in the Annealed and Heat Treated - Condition P To AS2837 - 1986 416 and BS970 Part3 1991 416S21
Condition Annealed P
Tensile Strength Mpa Min 550
Max 700
0.2% Yield Strength Mpa Min 340
Elongation on 5.65√S0 % Min 15
Impact Izod J Min 34
Hardness HB Min 152
Max 207 207
Material stocked generally in annealed condition 76.2 mm dia and larger.Material stocked generally in condition P up to and including 63.5 mm dia. NB. Check the mill certificate if critical for end use. 
Typical Mechanical Properties At Room Temperature - Annealed and Hardened and Tempered to Condition P
Condition Annealed *P
Tensile Strength Mpa 530 650
0.2% Yield Strength Mpa 290 490
Elongation in 50mm % 27 24
Impact Izod J 75 95
Hardness HB 160 190
*Typical Hardening Temperatures 950oC - 1010oC
*Typical Tempering Temperatures 650oC - 680oC
620oC - 660oC
Typical Mechanical Properties At Room Temperature - Hardened By Oil Quench at 980oC and Tempered as Indicated
Temperature oC 150 250 370 480 540 595 650 700
Tensile Strengt Mpa 1210 1190 1180 1100 950 780 710 660
0.2% Yield Strength Mpa 950 940 930 870 760 650 570 520
Elongation in 50mm % 10 11 14 15 16 17 21 22
Impact Izod J 27 34 34 *22 *34 54 65 105
Charpy J 27 30 30 *20 *30 54 68 100
Hardness HB 360 350 350 330 285 235 205 190
Rc 39 38 38 36 31 23 16 12
High tensile strength and high yield strength but low impact properties when tempered below 400oC.*Note drop in impact properties.Tempering within the range 400oC - 580oC should be avoided. 
Elevated Temperature Properties
While 416 displays a reasonable resistance to scaling in continuous service up to 650oC, it does however experience a substantial drop in tensile strength, creep and stress rupture strength at relatively low working temperatures. It is also susceptible to hot cracking due to its high sulphur content.NB. High temperature use is therefore not generally recommended. 
Low Temperature Properties
416 is not recommended for use at sub-zero temperatures due to a substantial drop in impact properties consistent with most steels other than the austenitic steel types.
Cold Bending
416 has limited cold bending properties and it is generally not recommended.
Hot Bending
In the hardened and tempered condition, it is not recommended due to its affect on the mechanical properties within the heat affected zone. Even in the annealed condition it should also be avoided if possible due to its susceptibility to hot cracking.
Corrosion Resistance
416 due to its higher sulphur content has lower resistance to all corrosion types than grade 410, and indeed all of the 400 series martensitic stainless steels.Its selection therefore is generally based upon its excellent machinability coupled with its lower corrosion resistance capabilities. NB. It has optimum corrosion resistance in the hardened and tempered condition and is not therefore recommended for use in the annealed condition.It is most important that oxygen is always allowed to circulate freely on all stainless steel surfaces to ensure that a chrome oxide film is always present to protect it. If this is not the case, rusting will occur as with other types of non stainless steels.

For optimum corrosion resistance surfaces must be free of scale and foreign particles.
Finished parts should be passivated.

 

Forging
Heat uniformly to 1150oC - 1200oC, hold until temperature is uniform throughout the section.Do not soak but commence forging immediately. Do not overheat as this can cause a loss of toughness and ductility.Do not forge below 900oC

Finished forgings should be cooled slowly in air, ashes or dry lime etc. to room temperature and annealed immediately.

NB. Severe upset forging of this grade is not recommended.

 

Heat Treatment
Sub-Critical Annealing
Heat uniformerly to 650oC - 750oC as required, hold until temperature is uniform throughout the section.*Soak as required, cool in air. 
Annealing
Heat to 820oC - 900oC, hold until temperature is uniform throughout the section. *Soak as required. Cool in furnace.
Hardening
Heat to 950oC - 1020oC, hold until temperature is uniform throughout the section. *Soak as required.Quench in oil or air cool. Temper immediately while still hand warm.  
Nitriding
Prior to nitriding, the chrome oxide film which protects the surface must be broken down by pickling or fine sand blasting.Nitriding is carried out at 500oC - 550oC followed by slow cooling (no quench) reducing the problem of distortion. Parts can therefore be machined to near final size, leaving a grinding tolerance only. Always ensure that the tempering temperature employed during the initial heat treatment was higher than the nitriding temperature otherwise the core strength will be affected. 
Tempering (Condition R)
Heat to 650oC - 750oC as required, hold until temperature is uniform throughout the section. *Soak as required. Cool in air.416 can of course be tempered at much lower temperatures, producing much higher tensile strengths, but with subsequent lower impact properties. NB. Tempering however within the range 400oC - 580oC should be avoided due to the brittleness, resulting in a considerable reduction in impact properties and loss of corrosion resistance.*Heating temperatures, rate of heating, cooling and soaking times will vary due to factors such as work piece size/shape, also furnace type employed, quenching medium and work piece transfer facilities etc.

Please consult your heat treater for best results.

 

Machining
416 was developed as a free machining grade and has by far the best machinability of all the 400 series martensitic stainless steels. It also has much better machinability than grade 303 free machining austenitic stainless steel and all operations such as turning, drilling, broaching, tapping, milling, reaming and threading etc. can be readily carried out as per machine manufacturers recommendations for suitable tool type, feeds and speeds.
Welding
416 is not generally recommended for welding in either the annealed or hardened and tempered condition, due to its high sulphur content resulting in hot cracking or its hardening capability resulting in cold cracking.If it is really necessary to weld in either condition the following procedure may be taken as a guide only. 
Welding Procedure
Welding electrodes or rods should be low hydrogen types 410 or *similar when strength is required or post-weld hardening and tempering, otherwise an austenitic stainless electrode or rod such as 308 or *similar may be used to give a more ductile weld, when strength is not so critical and post-weld annealing is not possible or intended.Pre-heat at 200oC - 300oC and keep heat input to a minimum to reduce dilution of sulphur and filler metal. On completion of welding cool slowly as possible until hand warm and as required: Post-weld sub-critical anneal at 650oC - 750oC or full anneal and harden and temper as required.*Please consult your welding consumables supplier.

 

Interlloy believes the information provided is accurate and reliable. However no warranty of accuracy, completeness or reliability is given, nor will any responsibility be taken for errors or omissions.

316L due to its low carbon content has greater resistance to intergranular corrosion than all the austenitic stainless steel grades except 304L grade and 321 titanium stabilized grade.