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SAE 8620 Chemical Composition

Table of contents

  • SAE 8620 chemical composition
  • AISI 8620 Steel Mechanical Properties
  • Equivalent grades and standards of Alloy 8620
  • UNS G86200 Material hardness
  • Forging temperature of DIN 1.6523
  • 21NiCrMo2 Grade Thermal Properties
  • SNCM220 Pre-heat Temperature
  • Physical properties of 8620 grade steel
  • SAE 8620 steel quality classification
  • AISI 8620 Normalizing & Annealing
  • SAE 8620 Carburizing
  • Difference between SAE 8620 Steel Mechanical Properties in Normalized & Annealed condition
  • Surface finish of AISI 8620 Steel
  • Alloy steel 8620 bar sizes and tolerance
  • EN362 steel Hot forming and heat treatment
  • SAE 8620 material Case Hardening Methods
  • AISI 8620 bar Mechanical Properties For Core – Carburised and Oil Quenched at 840 °C
  • 8620 hot rolled steel working temperature range
  • Stress Relieving of Low alloy steel 8620
  • SAE 8620 Machinability
  • 8620 Steel Testing and Inspection
  • AISI 8620 VS 4140 steel

SAE 8620 Chemical Composition

Manganese
0.7 to 0.9
Nickel
0.4 to 0.7
Chromium
0.4 to 0.6
Silicon
0.15 to 0.35
Carbon
0.18 to 0.23
Molybdenum
0.15 to 0.25
Sulfur
0 to 0.04
Phosphorus
0 to 0.035
Iron
96.9 to 98

AISI 8620 Steel Mechanical Properties

SAE 8620 Annealing 8620 Steel Normalizing
Temperature, °C 820-850 880-920
Cooling Speed Rate Slow Relatively fast
Cooling Furnace Cooling Air Cooling
Heat Treatment Cycle Long time Short time
Grain size Normal Good

21NiCrMo2 material has good toughness and strength properties, Refer 8620 Steel Equivalent

Equivalent Grades and Standards of Alloy 8620

Country BS DIN EN USA Japan
Standard BS 970 DIN 1654 EN 10084 ASTM A29 JIS G4103
Grades 805M20 1.6523/21NiCrMo2 1.6523/20NiCrMo2-2 8620 SNCM220

UNS G86200 Material Hardness

Hardness, Knoop 169
Hardness, Rockwell B 80
Hardness, Vickers 155

UNS G86200 is highly wear resistant, Check Forging temperature of SNCM220 Grade

Forging Temperature of DIN 1.6523

Forging Temperature 2250ºF (1230ºC)

AISI 8620 Steel is used in a variety of oilfield applications, Refer Alloy Steel 8620 Thermal Properties

21NiCrMo2 Grade Thermal Properties

Properties Imperial Metric
Thermal Conductivity 323 BTU in/hr.ft².°F 46.6 W/mK

SNCM220 Pre-heat Temperature

Section 40mm 50mm 75mm 150mm
oC 25 40 100 150
Alloy 8620 is heat treated in a temperature range of 660–780 °C, View SAE 8620 Material Physical Properties

Physical Properties of 8620 Grade Steel

Density g/cm³ 7.85
Melting Point Deg F 2600
Poisson’s Ratio 0.27-0.30
Thermal Expansion (20 ºC)(ºC⁻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

SAE 8620 Steel Quality Classification

SAE 8620 Steel Central Porosity (Grade) General Porosity (Grade) General Spot Segregation (Grade) Pattern Segregation (Grade)
Quality Steel ≤3.0 ≤3.0 ≤1.0 ≤3.0
High Quality Steel ≤2.0 ≤2.0 Not Allowed ≤2.0
Premium Quality Steel ≤1.0 ≤1.0 Not Allowed ≤1.0

AISI 8620 Normalizing & Annealing

8620 Steel Annealing SAE 8620 Normalizing
Temperature, °C 820-850 880-920
Grain Size Normal Good
Cooling Furnace Cooling Air Cooling
Surface Hardness, HBW 150-187 183-200
Cooling Speed Rate Slow Relatively Fast
Heat Treatment Cycle Long Time Short Time

SAE 8620 Carburizing

Carburizing Temperature Quenching Temperature Tempering Temperature Surface Hardness Core Hardness Effective Carburizing Layer Depth
900-920°C 780-800°C, Oil Quench 150-170°C 59-63 HRC above 30 HRC 1.4-1.8 mm

Difference Between SAE 8620 Steel Mechanical Properties in Normalized & Annealed Condition

Yield Strength Tensile Strength Elongation Impact Charpy-V Reduction of Area
Annealed 385 MPa 535 MPa 31.3% 112 J 62%
Normalized 355 MPa 635 MPa 26.3% 100 J 60%
DIN 1.6523 Bars Are Available In Square, Flat And Round Shapes, Check EN362 Steel Surface Finish

Surface Finish of AISI 8620 Steel

Black Finish

Black

Rough turned finish

Rough Turned

peeled finish

Peeled

Alloy Steel 8620 Bar Sizes and Tolerance

Form Sizes (mm) Manufacturing Process Tolerance Range
Flat/Square Thickness: 120-800 Hot Forged Black -0/+8mm
Width: 120-1500 Rough Machined -0/+3mm
Round 6-100 Cold Drawn Bright/Black Best H11
16-350 Hot Rolled Black -0/+1mm
Peeled/Ground Best H11
90-1000 Hot Forged Black -0/+5mm
Rough Turned -0/+3mm

EN362 Steel Hot Forming and Heat Treatment

Treatment Temperature Range (°C) Cooling
Carburizing 880-960 Oil (water), hot quench 160-250°C, Salt bath 580-650°C, Case hardening box, Air*
Case Hardening 780-820 Oil (water), hot quench 160-250°C*
Core Hardening 860-900 Oil (water), hot quench 160-250°C*
Intermediate Annealing 630-650 Air, Furnace
Tempering 150-200 Air

SAE 8620 Material Case Hardening Methods

  • Flame or Induction Hardening
  • Carburizing
  • Nitriding
  • Carbonitriding

AISI 8620 Bar Mechanical Properties For Core – Carburised and Oil Quenched at 840 °C

Section Size 11 mm 30 mm 63 mm
Tensile Strength MPa Min 980 780 690
Max 1270 1080 930
Elongation 5.65√S0 % Min 9 10 11
Yield Strength MPa Min 785 590 490
Charpy Impact J Min 41 41
Hardness RC Min 31 23 16
Max 41 35 29
Hardness HB Min 290 235 205
Max 375 320 275

8620 Hot Rolled Steel Working Temperature Range

Temperature up to 650°F (343°C)

Stress Relieving of Low Alloy Steel 8620

Stress Relieving 630°C – 650°C

SAE 8620 Machinability

Steel 8620 has a machinability rating of 66%.

8620 Steel Testing and Inspection

  • Chemical Analysis
  • Surface Hardness
  • Ultrasonic Test Report
  • Heat Treatment Process
  • Grain Size
  • Forging Ratio
  • Mechanical Properties
  • Non-Metallic Inclusion
SAE 8620 Testing Inspection

AISI 8620 VS 4140 Steel

SAE 8620 AISI 4140
Carbon Content 0.18%-0.23% 0.38%-0.43%
Hardness 25HRC 18-22 HRC

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