25CrMo4 1.7218 Alloy Steel

25CrMo4 Alloy Steel

Chemical composition

Mechanical Properties in Hardening and Tempering Condition

Delivery Condition
1.Shape:Round/Square / Flat/Shafts/Rollers/Blocks
2.Surface condition:Black surface/Bright surface
3.Heat Treatment:Normalized/Annealed/QT
4.Straightness:Max 3mm/m(Enhanced straightness may be available on request)
5.Length:3000-5800mm suitable for 20″container.  above 6000mm,suitable for 40″ container
6.Grain Size: 5-8 acc to ASTM E112-96
7.Ultrasonic Standard: Sep1921/ASTM A388/EN 10228-3
8.Non Metallic Inclusion: 2 max acc to ASTM E45 /K4≤20 acc to DIN 50602
9.Forging Ratio: minimum 4 : 1
10.Marking: Grade/Weight/Length/Size/Heat Number

Quality Certification
A material test report(Inspection Certificate EN 10204 3.1) will be provided, documenting the following:
1.Chemical analysis
2.Mechanical properties
3.Surface hardness
4.Non Metallic Inclusion
5.Heat Treatment Process
6.Grain size
7.Forging ratio
8.NDE test method/criteria

What Is 25CrMo4?

25CrMo4 is a heat-resistant, heat-treatable steel grade that is often used for components with high loads in motorsport, industry and in aviation. Among other things, screws, crankshafts, roll cages, chassis components and vehicle frames are made from this. Due to its chemical composition, 25CrMo4 is suitable for hardening and has a tensile strength of over 650 N / mm² in the tempered state. 25CrMo4 is valued for its good weldability and bendability.

Advantages of saw cut

The processing with the saw is a mechanical processing of the material, which results in a significantly lower unintended deformation and increased hardness for the existing structure, such as the thermal cutting. Thus, the machined workpiece has a homogeneous structure even at the edge, which does not change in the continuation of the material. This circumstance allows immediate finishing of the workpiece with milling or drilling . So it is not necessary to anneal the material or make a similar operation beforehand.

25CrMo4 – specification and applications

25CrMo4 steel is alternately classified as structural steel for heat improvement and as a boiler steel designed to work at elevated temperatures. It exhibits very good strength properties, high ductility, weldability and good hardenability. Compared to the 35HM and 34CrMo4 grades, after heat treatment it has slightly worse strengths, but it makes up for the lower properties with much better ductility.

25CrMo4 achieves best durability values at dimensions up to 65mm after hardening in water, while after hardening in oil at dimensions and thicknesses up to 40mm. It is most often found in a heat-treated or softened state – less commonly in the normalized state.

For use in high temperature applications – the power industry – this steel is used in the production of parts working at 450 – 530 ℃, which exhibit creep resistance: flanges and welds for pipes, covers, nuts, heavy-duty screws, turbine rotors, turbine blades, toothed shafts, steam pipes, control parts, and levers.

The material 25CrMo4 is a chrome-molybdenum alloyed tempering steel with good welding properties. Due to its chemical composition, it is suitable for tempering and due to the very good toughness has good tensile strengths, which is why it is used primarily for components in which these characteristics are very important.

Heat treatment

The material 25CrMo4 is at 1100°C – 850°C warm unshaped and then slowly cooled.

Normalized annealing: normalizing takes place at temperatures between 860°C – 900°C. Following by cooling in the air.

Soft annealing: the soft annealing of material grade 1.7218 takes place at 680°C – 720°C with subsequent, slow cooling.

Hardening: due to its chemical composition, the 25CrMo4 is well suited for hardening. Hardening can be carried out at temperatures of 840°C – 870°C, followed by quenching in water. Furthermore, curing at 850°C – 880°C is possible, followed by quenching in oil or aqueous polymer solution.

Tempering: with a holding time of at least one hour, the tempering can take place at temperatures between 540°C – 680°C. The subsequent cooling takes place in the air.

General mechanical properties of 25CrMo4 steel

Tensile strength, Rm > 740 MPa

Yield point, Re > 590 MPa

Contraction Z > 55%

Elongation A > 15%

Density = ~ 7,85 g/cm3

Notch toughness > 80 J

Hardness in softened annealed state < 217 HB

Heat treatment and its process

Soft annealing a t680 – 720℃ with slow cooling in the furnace

Normalizing annealing at 860 – 900 °C with slow cooling in air

Hardening in oil or water at 840 – 880℃

Tempering at 540 – 680 °C with cooling in air

Eelief annealing at 650 – 700℃

25CrMo4 – Form of Supply