8620 Alloy Steel Desctiption
AISI 8620 Steel is a low alloy nickel, chromium, molybdenum case hardening steel, generally supplied in the as rolled condition with a maximum hardness HB 255max. SAE steel 8620 offers high external strength and good internal strength, making it highly wear resistant. AISI 8620 steel has a higher core strength than grades 8615 and 8617.
SAE 8620 alloy steel is flexible during hardening treatments, thus enabling improvement of case/core properties. Pre hardened and tempered (uncarburized) 8620 can be further surface hardened by nitriding but will not respond satisfactorily to flame or induction hardening due to its low carbon content.
Steel 8620 is suited for applications which require a combination of toughness and wear resistance. This grade is commonly supplied in round bar.
AISI 8620 Steel Supply Range
8620 Round Bar: diameter 8mm – 3000mm
8620 Steel Plate: thickness 10mm – 1500mm x width 200mm – 3000mm
8620 Square Bar: 20mm – 500mm
8620 tubes are also available against your detailed request.
Surface Finish: Black, Rough Machined, Turned or as per given requirements.
AISI/SAE 8620 Alloy Steel Introduce
Lion Metal is one of the best AISI 8620 steel Manufacturers and Exporters, supplied with round,square,flat,block,and shaft etc.
AISI 8620 is defined as low carbon alloy steel which has 0.5% Cr, 0.2% Mo and 0.5% Ni as strengthening alloy elements.It is generally supplied as annealed condition with hardness HB255max.
AISI 8620 has good wear resistant with case hardness HRC 60-63 when carburized, hardened and tempered.
Compared with grades 8615 and 8617, it shows good core strength and toughness properties with a typical tensile strength range of 700-1100 MPa,in small to medium sized sections.
AISI 8620 is suited for applications which require a combination of toughness and wear resistance. it is commonly used in the engineering and automitive industries for toolholders and other such components.
Typical application:Arbors, pinions, bushes, camshafts, kingpins,ratchets, gears, splined shafts etc.
SUPPLY FORM & SIZE & TOLERANCE
| Supply Form | Size(mm) | Process | Tolerance | |
| Round | Φ6-Φ100 | Cold Drawn | Bright/Black | Best H11 |
| Φ16-Φ350 | Hot Rolled | Black | -0/+1mm | |
| Peeled/ground | Best H11 | |||
| Φ90-Φ1000 | Hot Forged | Black | -0/+5mm | |
| Rough Turned | -0/+3mm | |||
| Flat/Square/Block | Thickness :120-800 | Hot Forged | Black | -0/+8mm |
| Width:120-1500 | Rough Machined | -0/+3mm | ||
Remark:Tolerance can be customized as per requests
CHEMICAL COMPOSITION PER ASTM A29
| GRADE | C | Si | Mn | P | S | Cr | Mo | Ni |
| 8620 | 0.18-0.23 | 0.15-0.35 | 0.70-0.90 | ≤ 0.035 | ≤ 0.040 | 0.40-0.60 | 0.15-0.25 | 0.40-0.70 |
PHYSICAL PROPERTY
| Density g/cm3 | 7.85 |
| Melting point Deg F | 2600 |
| Poisson’s ratio | 0.27-0.30 |
| Machinability (AISI 1212 as 100% machinability) | 65% |
| Thermal expansion (20 ºC)(ºC ˉ ¹) | 12.2*10^-6 |
| Specific heat capacity J/(kg*K) | 477 |
| Thermal conductivity W/(m*K) | 46.6 |
| Electric resistivity Ohm*m | 2.34*10^-7 |
MECHANICAL PROPERTY
Typical Mechanical Properties For Core – Carburised and Oil Quenched at 840 °C
| Section Size | 11mm | 30mm | 63mm |
| Tensile Strength Mpa | 980-1270 | 780-1080 | 690-930 |
| Yield Strength Mpa | ≥785 | ≥590 | ≥490 |
| Elongation % | ≥9 | ≥10 | ≥11 |
| Charpy Impact J | ≥41 | ⬅ | ⬅ |
| Hardness HB | 290-375 | 235-320 | 205-275 |
| Hardness HRC | 31-41 | 23-35 | 16-29 |
HARDENABILITY LIMITS
| Distance from quenched end mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
| HRC Min | 41 | 37 | 31 | 25 | 21 | – | – | – | – | – | – | – | – |
| HRC Max | 48 | 47 | 43 | 39 | 35 | 32 | 30 | 29 | 26 | 24 | 23 | ⬅ | ⬅ |
Hardness values under 20HRC is not specified.
FORGING
Forging temperature should be carried out between 925℃-1230℃,AISI 8620 has low carbon content which is less susceptible to cracking than medium or high carbon steels,so it may be heated and cooled more rapidly.Soaking time at forging temperature should be as short as possible to avoid heavy scaling and excessive grain growth.The lower the forging-ending temperature ,the finer the grain size .Don’t forge below minimum forging temperature 850°C.This alloy should be cooled in sand.
NORMALIZING
Normalizing is used to refine the structure of forgings that might have cooled non-uniformly after forged,and considered as a conditioning treatment before case hardening.Normalizing temperature for AISI 8620 steel should be carried out between 900℃-925℃. hold suitable time for the steel to be thoroughly heated to complete the ferrite to austenite transformation.Cool in still air.This treatment is considered as another method of improving machinability.
ANNEALING
Full annealing is recommended for AISI 8620 before machining, AISI 8620 should be carried our at a nominal temperature of 820℃-850℃,hold suitable time for the steel to be thoroughly heated, then furnace cooling.
CASE HARDENING
Following core refining, Heat the temperature to 780oC – 820oC, hold suitable time for the steel to be thoroughly heated, and quench in oil.Temper as soon as possible after quenched.
TEMPERING
Tempering is usually carried out to relieve stresses from the hardening process,it will improve the toughness of both case and core, with only a little reduction in core strength and case hardness.Heat the AISI 8620 steel to 150oC – 200oC as required, hold enough time until temperature is uniform throughout the section, soak for 1 – 2 hours per 25 mm of section, and cool in still air.
CABURIZING
Pack, salt or gas carburize at temperature 900oC – 925oC, holding enough time to obtain the required case depth and carbon content, followed by a suitable hardening and tempering cycle to optimise case and core properties.
CERTIFICATE & THIRD-PARTY TESTING
AISI 8620 MTC Report
TUV Testing Report
