What is AISI 4140 Alloy Steel
AISI / SAE 4140 Steel is a chromium-molybdenum alloy steel known for its remarkable strength and versatility. SAE 4140 steel alloy material is extensively used in various applications because of its unique combination of toughness, strength, and other mechanical properties.
Composition and Characteristics
The chemical composition of alloy 4140 steel includes chromium, molybdenum, manganese, and carbon. This distinct mixture contributes to its high tensile strength, superior hardness, and excellent toughness. The steel’s alloying elements also provide good resistance to corrosion and oxidation.
| Grade | C | Mn | P | S | Si | Cr | Mo |
| 4140 | 0.38-0.43 | 0.75-1.00 | 0.035 | 0.040 | 0.15-0.35 | 0.8-1.10 | 0.15-0.25 |
Key Properties and Applications
AISI / SAE 4140 alloy-steel is known for its high yield strength and density, making it an ideal choice for critical applications in automotive, aerospace, and oil and gas industries. Its high fatigue strength and resistance to wear and tear make it suitable for manufacturing gears, bolts, and other high-stress components.
Heat Treatment and Hardening
The heat treatment of 4140 steel is crucial in achieving desired mechanical properties. Usually to achieve higher strength, we usually do quenching and tempering to get higher hardness and strength. Hardening 4140 steel alloy can significantly increase its wear resistance, making it suitable for high-stress applications. For the same steel materials, we can achieve different mechanical properties by adjust the heating temperature and last time of the heating actually. So, it’s important to have the required specification for us to evaluate the technical requirements before any dispute.
Machinability and Weldability
Regarding machinability, SAE 4140 alloy material exhibits excellent characteristics, especially in annealed or normalized conditions. Welding 4140 steel material requires specific techniques to maintain its mechanical properties. Preheating and post-weld heat treatment are often necessary to prevent cracking.
Comparison with Other Alloys
When comparing 4140 steel with other steels like 4340, it stands out due to its optimal balance of strength, toughness, and wear resistance. Its low alloy steel composition ensures a good balance between strength and ductility.
Other designations equivalent to AISI 4140 materials are listed in the following table.
AMS 6349 ASTM A193 (B7, B7M) ASTM A506 (4140) ASTM A752 (4140)
AMS 6381 ASTM A194 (7, 7M) ASTM A513 ASTM A829
AMS 6382 ASTM A29 (4140) ASTM A513 (4140) SAE J1397 (4140)
AMS 6390 ASTM A320 (L7, L7M, L7D) ASTM A519 (4140) SAE J404 (4140)
AMS 6395 ASTM A322 (4140) ASTM A646 (4140) SAE J412 (4140)
AMS 6529 ASTM A331 (4140) ASTM A711
Physical Properties
The physical properties of SAE 4140 steel, such as its magnetic properties, hardness (Rockwell C scale), and tensile strength, make it a versatile choice for various industrial applications. Its modulus of elasticity and carbon content contribute to its overall strength and machinability.
Cost and Availability
Considering cost, 4140 steel is an economically viable option, providing a good balance between cost and performance. It is readily available in various forms like bars, hex bars, and plates, making it accessible for diverse industrial uses. You can contact us for the best price on sale for either 4140 alloy steel plate / flat bar or 4140 alloy steel round bar.
FAQs About 4140 Alloy Steel
- Is SAE 4140 alloy-steel magnetic?Yes, due to its iron content, SAE 4140 alloy steel exhibits magnetic properties.
- How does the AISI 4140 steel differ from other steels?AISI 4140 offers a unique combination of strength, toughness, and resistance to wear, distinguishing it from other steel grades.
- Can AISI 4140 engineering steel be used in high-temperature applications? Yes, 4140 steel maintains good strength and toughness at higher temperatures.
- What are the challenges in machining and welding SAE 4140 steel ? Machining requires maintaining a balance between hardness and toughness, while welding requires preheating and post-weld heat treatment to prevent cracking.
- How does the cost of AISI 4140 steel compare to other alloys? 4140 alloy steel is cost-effective, offering a good performance-cost ratio compared to other alloy steels.
Final
4140 Alloy Steel stands out as a highly versatile and efficient material in the steel industry. For any inquiries about our 4140 steel plate or round bar, please contact us at jeremy@otaisteel.com or via WhatsApp at +8613610149979. We supply top quality AISI 4140 steel for your own stock or your project.
