SAE AISI 4130 Chromoly Steel, Alloy Material Properties, Chemical Composition
AISI 4130 Chromoly Steel (UNS G41300)
AISI 4130 steel (UNS G41300), also known as 4130 Chromoly steel, is a chrome-molybdenum series low alloy steel with high strength, toughness and hardenability, usually used in quenched and tempered condition.
Uses
AISI SAE 4130 alloy steel can be made into steel plate, steel sheet, round and flat steel bar, steel pipe and tube, etc. and has many uses in pressure vessels, pumps and valves, pinions, shaft gears, ball studs, screws, general purpose profile steel, automotive parts, oil and gas industry, aerospace, and bike frame, etc.
Datasheet & Specification
Below is material AISI 4130 Chromoly steel datasheet including chemical composition, density, thermal expansion coefficient, thermal conductivity, yield strength, hardness, etc.
AISI SAE 4130 Chemical Composition
The table below lists AISI 4130 chemical composition.
| AISI 4130 Chemical Composition (%) | |||||||
| Steel Grade (UNS) | C | Si | Mn | P (≤) | S (≤) | Cr | Mo |
| 4130 (G41300) | 0.28-0.33 | 0.15-0.35 | 0.40-0.60 | 0.035 | 0.040 | 0.80-1.10 | 0.15-0.25 |
AISI 4130 Material Properties
Material AISI 4130 steel mechanical properties are given in the table below.
| Steel (UNS) | Tensile strength (Mpa) | Yield strength (Mpa) | Elongation in 50 mm, % | Reduction in area, % | Hardness (HB) | Sample diameter | Conditions |
| AISI 4130 (G41300) | 670 | 435 | 25.5 | 59.5 | 197 | 25mm (1 inch) | Normalized at 870 °C (1600 °F) |
| 560 | 460 | 21.5 | 59.5 | 217 | Annealed at 865 °C (1585 °F) | ||
| 1040 | 979 | 18.1 | 63.9 | 302 | Water quenched from 855 °C (1575 °F) & tempered at 540 °C (1000 °F) |
AISI SAE 4130 Physical Properties
Notes: 10-6/K = 10-6.K-1 = (µm/m)/°C
| AISI SAE 4130 coefficients of linear thermal expansion | |
| Value (10-6/K) | Temperature (°C) |
| 12.2 | 20-100 |
| 13.7 | 20-400 |
| 14.6 | 20-600 |
| Material 4130 chromoly thermal conductivity | ||
| Value (W/m·K) | Temperature (°C) | Treatment or condition |
| 42.7 | 100 | Hardened and tempered |
| 40.6 | 300 | |
| 37.3 | 500 | |
| 31.0 | 700 | |
| Specific Heat of AISI 4130 Alloy Steel | ||
| Value (J/Kg·K) | Temperature (°C) | Treatment or condition |
| 477 | 50-100 | Hardened and tempered |
| 515 | 150-200 | |
| 544 | 250-300 | |
| 595 | 350-400 | |
| 657 | 450-500 | |
| 737 | 550-600 | |
| 825 | 650-700 | |
| 833 | 750-800 | |
| Electrical Resistivity of AISI SAE 4130 Alloy Steel | ||
| Value (μΩ·m) | Temperature (°C) | Treatment or condition |
| 0.22 | 20 | Hardened and tempered |
| 0.27 | 100 | |
| 0.34 | 200 | |
| 0.53 | 400 | |
| 0.79 | 600 | |
| 1.10 | 700 | |
| 1.17 | 900 | |
| 1.22 | 1000 | |
SAE 4130 Steel Heat Treatment
The following table shows alloy 4130 chromoly steel heat treatment and rockwell hardness.
| Chromoly 4130 Steel Heat Treatment | |||
| 4130 Heat Treat | Temperature (℃) | Hardness | Cooling/Agent |
| Normalizing | 885 | 197 HB | Air |
| Annealing | 865 | 156 HB | Furnace cooling |
| Quenching | 800-855 | Water | |
| Tempering (2 hour) | 204 | 47 HRC | Water hardening |
| 260 | 45 HRC | ||
| 315 | 43 HRC | ||
| 370 | 42 HRC | ||
| 425 | 38 HRC | ||
| 480 | 34 HRC | ||
| 540 | 32 HRC | ||
| 595 | 26 HRC | ||
| 649 | 22 HRC | ||
Normalizing
4130 alloy steel is typically normalized at 900 °C (1650℉), and should be cooled at a specified temperature in still air.
Spheroidizing Annealing
For spheroidizing annealing of 4130 alloy steel, it needs heat treated to 749 °C (1380 °F), followed by slowly cooling to 666 °C (1230 °F) at a rate of 6 °C (10 °F)/hour, or rapid cooling to 675 °C for 8 hours isothermal annealing.
Full Annealing
Heat treatment to 855 °C (1570 °F), slow cooling from 760 °C (1400 °F) at a rate of 18 °C (35 °F)/hour to 666 °C (1230 °F), or rapid cooling to 674 °C (1245 °F) for 4 hours isothermal annealing.
Tempering
Tempering temperature of 4130 alloy steel can be from 204-649 °C (400-1200°F) after normalizing and water quenching, and the corresponding Rockwell hardness can be obtained.
Forging
Material 4130 alloy steel forging temperature is about 1204 °C (2200 °F)
Welding 4130 Steel
All common arc welding processes, such as (SAW, SMAW, FCAW, GMAW, GTAW) can be used to weld 4130 alloy steel, but in order to prevent cracking, it must be preheated to 150-290 °C before welding, preheating interpass temperature depends on the section thickness of the steel.
Equivalent Grade
AISI 4130 equivalent to European EN (Germany DIN EN, British BSI, French NF…), Chinese GB and Japanese JIS standard.
| AISI 4130 equivalent | |||||||||||
| USA | European Union | China | Japan | ISO | |||||||
| Standard | Grade (UNS) | Standard | Grade | Standard | Grade (Steel Number) | Standard | Grade | Standard | Grade | Standard | Grade |
| AISI; SAE; ASTM A29/A29M | 4130 (G41300) | AMS | AMS 6350; AMS 6345 | EN 10083-3 | 25CrMo4 (1.7218) | GB/T 3077 | 30CrMo | JISG 4105 | SCM430 | ||
