Cr12MoV (cast molding) metallographic diagram

Cr12MoV is an ultra-high strength tool steel known for its excellent fatigue properties and its ability to retain its strength even at elevated temperatures. This material is commonly used for the manufacture of cutting tools, mining tools, knife blades and punches and dies. Its high degree of wear resistance, corrosion resistance, and strength makes it ideal for a host of applications.

The name of the steel is derived from the combination of two elements: chrome (Cr) and molybdenum (Mo). The “V” stands for vanadium, which is added to the material to further increase its wear resistance and allow it to hold a sharp edge for longer periods of time.

Chemically, the composition of Cr12MoV is as follows: 12% chromium, 0.5-0.8% molybdenum, 0.18-0.25% carbon, and 0.25-0.4% vanadium. It is a martensitic stainless steel with a hardened structure consisting of ferrite and carbide.

Cr12MoV is usually manufactured through an investment-casting method, where molten metal is poured into a mold. In some cases, due to the complexity of the item being manufactured, a die-casting process is used instead. The material must then be heat treated, which consists of hardening and tempering in order to achieve the desired properties.

The hardening treatment usually begins with preheating, which should be done gradually to avoid cracking. This is followed by austenitization, which is heating the steel to its austenitic point. Quenching is then performed to rapidly cool the steel, which is followed by a tempering process. Temperatures used will vary depending on the desired properties, but they can range anywhere from 250-670 °C.

As a result of this treatment, the steel achieves a hardness of 58-60 HRC, and it exhibits good wear resistance and fatigue strength. The high chromium content also gives it good corrosion resistance to most acids and alkalis.

In summary, Cr12MoV is an ultra-high strength tool steel that combines excellent wear, fatigue and corrosion resistance. Its hardening treatment results in a hardness of 58-60 HRC, making it suitable for applications such as cutting tools, mining tools, knife blades and punches and dies. Additionally, its low cost and relatively easy manufacture make it a popular choice for a variety of applications.

Cr12MoV Steel, also known as D2 steel and X165CrMoV12, is an air-hardening, cold work, high carbon, high chromium steel containing molybdenum and vanadium. It has a relatively high level of wear resistance and toughness, making it a suitable material for high wear applications such as moulds and dies.

The microstructure of Cr12MoV features a ferrite matrix with small carbides and carbides of other elements. There are two main microstructures observed in this steel—pearlite and troostite. Pearlite is an aggregate of ferrite and cementite, and it usually appears in a plate-like structure. Troostite is a eutectoid structure of ferrite and cementite and is formed when pearlite transforms to a higher carbon content.

Examining the metallography of Cr12MoV will reveal a pearlitic microstructure. The micrograph reveals that there are a large number of fine carbides distributed throughout the ferrite matrix. The carbides consist of particles of chromium carbide, as well as lesser amounts of other carbides, such as vanadium, molybdenum, and titanium.

In addition to the pearlitic microstructure, there are traces of martensite present in the microstructure. Martensite is a hard and brittle form of steel that can be formed when the steel is further hardened and quenched. However, the amount of martensite present is usually very small, and this steel does not tend to form a martensite-like microstructure.

Overall, the microstructure of Cr12MoV indicates good wear and heat resistance, as well as good toughness due to the presence of fine carbides. It is an ideal material for mould and die making, as it can withstand consistent wear and heat without significant degradation.