4130 sheet
Grade 4130 steel plate, also known under designations such as EN 1.7218, or the trade name 25CrMo4, belongs to the category of low-alloy steels based on chromium and molybdenum. This alloy has gained a special place in many advanced industries due to its high tensile strength, good hardenability, acceptable toughness, and the ability to undergo precise heat treatments.
This steel is specifically used for manufacturing components exposed to severe mechanical or dynamic loads. Examples include shafts, gears, power transmission axles, and pressure-bearing parts in oil and gas industries. Its ideal balance between mechanical strength and processability makes it a reliable choice for critical industrial projects.
Chemical Composition of 4130 Steel Plate
The precise chemical composition of this steel grade plays a decisive role in its mechanical and thermal properties. The table below outlines the approximate weight percentage of its main elements:
Chromium enhances oxidation resistance and hardenability, while molybdenum contributes to the alloy’s structural stability under heat and stress.
Mechanical Properties of 4130Steel
When normalized and tempered4130 steel exhibits the following mechanical characteristics:
Ultimate Tensile Strength: ~560 MPa
Yield Strength: ~460 MPa
Elongation: ~21% (indicative of good toughness)
Brinell Hardness (HB): ~217
Young’s Modulus: ~210 GPa
These properties make it suitable for both structural parts and applications demanding high wear resistance.
Heat Treatment Capabilities
4130 steel responds well to various heat treatments, allowing adjustment of its physical and mechanical properties based on application:
Hot forming temperature: 850 – 1050°C
Tempering (stress relieving): 550 – 650°C
Soft annealing: Around 650°C for internal stress relief
Quenching: In oil or water, depending on thickness and desired hardness
This versatility in heat treatment makes it highly popular for producing complex components.
Key Applications of 7218 Steel Plate
A) Defense Industry Applications:
Properties like high pressure resistance, heat tolerance, hardenability, and notable toughness make this alloy highly reliable for sensitive military parts:
Structural and internal components of armored vehicles requiring high strength with moderate weight
Mechanical parts of weapon systems subjected to harsh physical and thermal conditions
High-pressure pipes and tanks in hydraulic or heavy-duty military chassis
Shafts and power transmission components in tanks, APCs, and heavy military vehicles
A major advantage of 25CrMo4 steel in defense is its precise machinability and customizable mechanical properties through heat treatment—key for advanced and sensitive equipment.
B) Automotive Industry:
Used in drive shafts, transmission axles, and steering knuckles
C) Aerospace Industry:
Used for pressurized components and lightweight high-strength parts
D) Oil & Gas Sector:
Employed in high-pressure pipelines, wellhead fittings, and drilling equipment
E) Industrial Machinery:
Used in gears, turbine blades, rods, and motion transfer pins
Advantages of 25CrMo4 Steel Plate
High hardenability under heat
Suitable toughness even at low temperatures
Weldable with standard alloy electrodes
Acceptable wear resistance in high-stress environments
Limitations and Considerations
Despite its advantages, a few factors should be kept in mind:
Higher cost compared to plain carbon steels
Requires precise control of temperature and time during heat treatment to achieve desired properties
Improper welding can lead to thermal cracking
SSAB STEEL SAZEH, a specialized supplier of alloy, stainless, and heat-resistant steels in Iran, leverages years of experience and direct cooperation with reputable foreign manufacturers—particularly from China—to provide high-quality products at competitive prices with rapid delivery.
This company has successfully introduced plates like 4130or(7218)to the Iranian market and stands ready to collaborate with various industries, including defense, oil and gas, energy, and heavy machinery, for the ongoing supply of premium-grade industrial plates.
