AISI 8620 steel Manufacturer and Exporter,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.
1.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
2.Chemical Composition
| Standard | Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
| ASTM A29 | 8620 | 0.18-0.23 | 0.15-0.35 | 0.7-0.9 | ≤ 0.035 | ≤ 0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
EN 10084 | 1.6523 | 0.17-0.23 | ≤ 0.04 | 0.65-0.95 | ≤ 0.025 | ≤ 0.035 | 0.35-0.70 | 0.4-0.7 | 0.15-0.25 |
| 20NiCrMo2-2 | |||||||||
| JIS G4103 | SNCM220 | 0.17-0.23 | 0.15-0.35 | 0.6-0.9 | ≤ 0.03 | ≤ 0.03 | 0.4-0.65 | 0.4-0.7 | 0.15-0.3 |
| BS 970 | 805M20 | 0.17-0.23 | 0.1-0.4 | 0.6-0.95 | ≤ 0.04 | ≤ 0.05 | 0.35-0.65 | 0.35-0.75 | 0.15-0.25 |
| GB 3077 | 20CrNiMoA | 0.17-0.23 | 0.17-0.37 | 0.6-0.95 | ≤ 0.035 | ≤ 0.035 | 0.4-0.7 | 0.35-0.75 | 0.2-0.3 |
3.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 |
4. 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 | ≥41 | ≥41 |
| Hardness HB | 290-375 | 235-320 | 205-275 |
| Hardness HRC | 31-41 | 23-35 | 16-29 |
5.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 | 23 | 23 |
Hardness values under 20HRC is not specified.
6.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.
7.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.
8.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.
9.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.
10.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.
11.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.
12.Applications
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.
AISI 8620 STEEL BUYING GUIDE
Are you worrying about finding suitable gear materials? Congratulations, you have found the right place.
Here, we will introduce to you AISI 8620, a gear steel with excellent performance, including its basic knowledge, main features, performance and other useful information.
Through this guide, we believe that it can help you solve problems and gain self-confidence.So, what are you waiting for? Let’s start!
WHAT DOES AISI 8620 MEAN?
In the market, we can often see AISI 8620 or SAE8620, in fact, they all refer to 8620 steel,the difference is that one is named by the American Iron and Steel Institute (AISI) and the other is named by the Society of Automotive Engineers (SAE).They jointly developed and shared a set of steel grade numbering system:Unified Numbering System,referred to as UNS.Here,we can find UNS G86200, it is the number for 8620 steel.
For 8620, The first number ‘8’ indicates that the steel is Nickel Chromium Molybdenum Steel,and 86XX means 0.5%Ni,0.5%Cr,0.2%Mo.
The last two numbers ‘20’ indicates the amount of carbon present in the steel. For this grade it has 0.20% carbon same as AISI 1020 steel.
In 86XX series,besides 8620 steel,8622 and 8625 is also commonly used in the industry,we can the difference in composition in the following table
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
| 8620 | 0.18-0.23 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
| 8622 | 0.20-0.25 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
| 8625 | 0.23-0.28 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
WHAT IS CASE HARDENING STEEL?
In sliding contact with hard or abrasive materials, the wear of steel materials is inevitable in daily use. How to slow down its wear? After continuous practice, increasing the surface hardness is an effective way to effectively resist surface wear. This is the origin of case hardening steel.
From the EN10084 standard, case hardening steel refers to steels with a relatively low carbon content which are intended for carburising or carbonitriding and subsequent hardening.In the standard, we can clearly see that carbon steel and alloy steel are suitable for case hardening, and the amount of carbon is less than 0.3%.
Types of Case Hardening Methods
- Flame or induction hardening
- Carburizing
- Nitriding
- Carbonitriding
The significant difference between Flame or Induction hardening and the last three methods is that Flame or Induction Hardening does not change the chemical composition of the material, which is just a topical heat treatment process, so it is usually only suitable for high carbon steel having sufficient reaction to quenching.
QUICK FAQS FOR AISI 8620 STEEL
Is AISI 8620 Steel Gear Steel?
Yes,AISI 8620 steel, as a CR-Ni-Mo series case hardening steel, is widely used in carburizing and carbonitriding process,and commonly used in the manufacture of gears in the engines and transmission systems of small and medium-sized cars and tractors.
What is AISI 8620H?
In fact, there is no difference in chemical composition between 8620H and 8620.While add ‘H’, this means that 8620 steel is required to ensure hardenability.
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
| 8620 | 0.18-0.23 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
| 8620H | 0.17-0.23 | 0.15-0.35 | 0.60-0.95 | ≤0.035 | ≤0.04 | 0.35-0.65 | 0.35-0.75 | 0.15-0.25 |
Can AISI 8620 Steel be Cold Drawn?
AISI 8620, as a low-carbon low-alloy steel, has higher strength than ordinary low-carbon steel, and good plasticity and toughness.
Yes, it can be cold drawn,and it is better to do cold drawing after annealing.After cold drawing, AISI 8620 steel has a smooth surface and precise dimensions, which is suitable for further processing, such as carburizing.
How Hard is AISI 8620 Steel？
AISI 8620, as a low-carbon alloy steel, under conventional heat treatment, such as annealing and normalizing, the hardness is generally not high, less than 200HBW.
But after carburizing and quenching, it has a very high hardness value, reaching 60HRC, and the core reaches about 35HRC,which is suitable for working under heavy load and impact.
Is AISI 8620 Same as 20NiCrMo2-2?
Although their chemical compositions are very similar, they are equivalent grades. AISI 8620 is the grade of the American standard ASTM A29, while 20NiCrMo2-2, also refers to DIN 1.6523, comes from the EN10084 European standard.
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
| 8620 | 0.18-0.23 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
| 20NiCrMo2-2/1.6523 | 0.17-0.23 | ≤0.4 | 0.65-0.95 | ≤0.025 | ≤0.035 | 0.35-0.70 | 0.4-0.7 | 0.15-0.25 |
Other Equivalent Grade
China/GB 3077: 20CrNiMoA
Japan/JIS G4103: SNCM220
UK/BS970:805M20
HEAT TREATMENT FOR AISI 8620 STEEL
AISI 8620 Normalizing & Annealing
- Process comparison
| AISI 8620 Normalizing | AISI 8620 Annealing | |
| Temperature,℃ | 880-920 | 820-850 |
| Cooling | Air Cooling | Furnace Cooling |
| Cooling Speed Rate | Relatively fast | Slow |
| Grain size | Good | Normal |
| Heat Treatment Cycle | Short time | Long time |
| Surface Hardness,HBW | 183-200 | 150-187 |
- Mechanical Properties
| Tensile Strength | Yield Strength | Elongation | Reduction of Area | Impact Charpy-V | Hardness | |
| Normalizing | 1020Mpa | 655Mpa | 17.7% | 47% | 23 | 302HBW |
| Annealing | 655Mpa | 415Mpa | 25.7% | 57% | 55 | 197HBW |
How to Carburize AISI 8620 Steel？
- AISI 8620 Isothermal Normalizing
Before carburizing AISI 8620 steel, it is first subjected to isothermal normalizing as a preliminary heat treatment.The purpose is to
eliminate or improve various structural defects caused by hot working, obtain easy-to-cut microstructure and hardness, improve microstructure and distribution, refine grains, and prepare microstructure for the carburizing and quenching process.
AISI 8620 steel requires a hardness of HB156-207 after isothermal normalizing, and the structure is uniform pearlite plus ferrite. Generally, normalizing tends to appear bainite structure, which leads to material brittleness and higher hardness, which is not conducive to cutting. Therefore, the isothermal normalizing process should suppress the appearance of bainite structure.
The previous steps of AISI 8620 steel isothermal normalizing, such as heating temperature and holding time are the same as ordinary normalizing.After the heat preservation is completed, cool to an isothermal temperature of about 700℃, so that the supercooled austenite is transformed in this temperature range, and a finer (relative to isothermal annealing) pearlite structure is obtained, finally air-cooled.
- AISI 8620 Carburizing
The carburizing and quenching process of AISI 8620 steel can be carburized with slowly cooling, followed by secondary heating and quenching & tempering. This method can refine the grains, reduce the amount of retained austenite after quenching, increase the quenching hardness, increase the strength of the carburized layer, and reduce deformation.
Carburizing Temperature:900-920℃
Quenching Temperature:780-820℃
Quenching Meduim:Oil
Tempering Temperature:150-200℃
Surface Hardness: above 58HRC
Core Hardness:35-47HRC
Effective Case Hardened Layer Depth: 1.7-2.1mm
AISI 8620 VS 17CRNIMO6
First of all, they are all case hardening steel. The difference is that AISI 8620 comes from the American standard, and 17CrNiMo6,also refers to 18CrNiMo7-6(EN10084 Standard), belongs to the grade in the German DIN17210 standard.Next, let’s briefly discuss the difference between these two steel grades.
- Chemical Composition
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo |
| 8620 | 0.18-0.23 | 0.15-0.35 | 0.70-0.90 | ≤0.035 | ≤0.04 | 0.4-0.6 | 0.4-0.7 | 0.15-0.25 |
| 17CrNiMo6/1.6587 | 0.15-0.20 | ≤0.4 | 0.4-0.6 | ≤0.035 | ≤0.035 | 1.5-1.8 | 1.4-1.7 | 0.25-0.35 |
From the above table,we can see that although they are both low-carbon alloy steels, the difference in the elemental composition of Cr Ni Mo is still very obvious.Due to these differences, the manufacturing cost is obviously higher than 8620 steel.
- Hardenability Limits
| Distance from quenched end mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | |
8620 | HRC Min | 41 | 37 | 31 | 25 | 21 | – | – | – | – | – | – | – | – |
| HRC Max | 48 | 47 | 43 | 39 | 35 | 32 | 30 | 29 | 26 | 24 | 23 | 23 | 23 | |
17CrNiMo6 | HRC Min | 40 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 32 | 31 | 30 | 29 | 29 |
| HRC Max | 48 | 48 | 48 | 48 | 47 | 47 | 46 | 46 | 44 | 43 | 42 | 41 | 41 | |
From the above table of end quenching test,We can clearly see the difference in data between AISI8620 and 17CrNiMo6. It can be said that the hardenability of 17CrNiMo6 is significantly better than AISI 8620 steel.Therefore, when we choose an application, we should fully consider the properties of the material to make the best use of it.
- Industrial Application
As a representative of the Cr-Ni-Mo series, in the automotive field, the American standard AISI 8620 steel is usually used in light and medium-sized vehicles to meet the requirements of the use of small and medium-sized modular gear steels, while the German standard 17CrNiMo6 steel is used in heavy vehicles. It is suitable for manufacturing large-modulus and heavy-duty automobile gears.
17CrNiMo6 Gears For Further Processing
WHERE CAN YOU BUY HIGH-QUALITY AISI 8620 STEEL?
With rich manufacturing experience for more than 15 years in the field of special steel manufacturing,we can not only manufacture high-quality AISI 8620 steel, but also provide one stop service solution,including heat treatment,machining and cutting.When you are looking for AISI 8620 steel, we will always be your best choice.
What We Supply For AISI 8620 Steel
| 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 | ||
Heat Treatment:Normalized(+N),Annealed(+A)
What Size We stock For AISI 8620 Steel
- Hot Rolled Round Bar:Φ16-Φ300mm,7 Days Delivery
- Hot Forged Round Bar:Φ140-Φ250mm,15 days Delivery
- Customized service：Special Size & Length,30 days Delivery
- Free Sample of AISI 8620 Steel
