Cr12MoV is an alloy steel that combines chromium, molybdenum and vanadium, providing excellent resistance to wear, fatigue and galling. For optimum hardness and toughness, it is usually supplied in an annealed and then tempered condition, with a typical hardness of HRC25-35 and a good balance of mechanical properties. This steel is used in a variety of applications, including cutting tools, high-speed tooling, and bearings, valves and other components that must endure harsh operating conditions.
The purpose of heat treating the Cr12MoV alloy is to improve its strength and wear resistance, as well as its other mechanical properties. Through the process of heat treatment, the alloy can be hardened, tempered, and annealed to create the desired properties. When heat treating Cr12MoV, it is important to keep in mind that because of its high nickel content, it is susceptible to cracking, particularly when hot.
The following is a detailed description of the heat treatment process for Cr12MoV:
First, the alloy is preheated in a furnace to a temperature between 1050°C - 1150°C. This serves to both homogenize the alloy and reduce the hardness.
Once the temperature has reached the desired range, the material is then quenched in oil or water to achieve maximum hardness. After quenching, the material is tempered at a temperature ranging from 150-350°C. This step relaxes the stresses created during the quenching process and increases the toughness of the material.
Finally, the material can be annealed at a temperature of 680°C to improve the surface finish and regain ductility.
The purpose of the heat treat process for Cr12MoV is to produce an alloy steel with a high degree of strength, wear resistance, and other desirable mechanical properties. By carefully monitoring the application of the heat treatment process, Cr12MoV can be an ideal choice for a variety of applications in need of a material that is both hard and tough.
Figure 1 below represents a ball-and-burr diagram of a heat-treated Cr12MoV sample. The top line represents the maximum hardness obtained, about HRC45-50, corresponding to a quench/temper cycle of 1050-1050/300-350°C, respectively. The bottom line represents the hardness achieved after annealing the sample at 680°C, approximately HRC35-40, which corresponds to a more ductile material.
Figure 1: Ball-and-burr diagram of a heat-treated Cr12MoV sample
Because of the alloy’s composition of chromium, molybdenum, and vanadium, the Cr12MoV steel alloy is highly resistant to wear, fatigue, and galling, and provides excellent mechanical properties. With proper heat treatment, this alloy can be utilized in applications requiring good strength and wear resistance. Furthermore, Cr12MoV is also one of the most popular alloy steels for shock absorbers, drive-train components, and machined parts that are subject to frequent and repeated impact loading, due to its combination of toughness and fatigue resistance.
