ThePipingMart Blog Grades ASTM A691 CM 75 Alloy Steel – Composition, Properties and Uses

ASTM A691 CM 75 Alloy Steel – Composition, Properties and Uses

Alloy Steel Grade CM 75

If you are looking for hard, strong, and durable steel with good corrosion resistance and heat resistance, look no further than alloy steel grade CM 75. This type of steel has various uses in various industries and has excellent physical and mechanical properties. Let’s take a closer look at the composition, chemical properties, mechanical properties, physical properties, uses, corrosion resistance, heat resistance, heat treatment, machining and welding of alloy steel grade CM 75.


Grade CM75 is composed mainly of Iron (Fe) with small additions of Carbon (C), Vanadium (V) and Niobium (Nb). The Iron content in the composition ranges from 74-77%, while other elements like Carbon range from 0.5-1%. Vanadium is present in trace amounts while Niobium is usually absent.

Chemical Properties

Steel Grade CM75 has an excellent combination of chemical properties such as high strength-to-weight ratio and good wear resistance due to its high carbon content. It also offers good toughness due to its alloying elements like vanadium and Niobium which increase its strength. Furthermore it has good abrasion resistance due to its high hardness which makes it ideal for applications where wear is a major concern.

Mechanical Properties

Alloy CM75 has excellent mechanical properties, including very high tensile strength at up to 2200 MPa as well as very good ductility even at elevated temperatures up to 800°C making it suitable for applications where both strength and ductility are important considerations.

Physical Properties

Grade CM75 exhibits excellent physical properties such as low thermal expansion coefficient making it suitable for use in applications where temperature changes may be an issue. It also has very good electrical conductivity making it suitable for use in electrical applications where conductivity is important. Additionally, it has very good magnetic permeability making it suitable for use in applications requiring magnetic shielding or sensing capabilities.


Alloy Steel Grade CM 75 can be used in many different industries including automotive parts manufacturing, agricultural equipment manufacturing, construction equipment manufacturing, shipbuilding industry and mining industry among others due to its excellent combination of mechanical and physical properties as well as its wear resistance characteristics . It can also be used in engineering components such as gears shafts or other components requiring strong material that can withstand extreme conditions without losing its integrity .

Corrosion Resistance

Alloy Steel Grade CM75 has excellent corrosion resistance compared to other steels due to its higher chromium content which helps protect the metal from oxidation by forming a protective layer over the surface of the metal . This layer prevents the metal from corroding even when exposed to water or other corrosive substances .

Heat Resistance

Alloy Steel Grade CM 75 has very good heat resistance making it suitable for use in high temperature applications such as power generation , petrochemical production , aerospace industry etc . Its heat resistant qualities make it ideal for components that need to operate under extreme temperatures without losing their structural integrity .

Heat Treatment

Alloy Steel Grade CM75 can be heat treated through quenching , tempering or normalizing processes depending on the desired end result . Quenching involves heating the metal above its critical temperature followed by rapid cooling through water or oil baths whereas tempering involves reheating after quenching followed by cooling at lower temperatures . Normalizing involves heating above critical temperature followed by a slow cooling process either naturally or through air blowers .


Alloy Steel Grade CM 75 can be machined using conventional machining techniques however care should be taken when cutting this material since sharp edges can create stress risers resulting in cracks during operation .


Alloy Steel Grade CM 75 can be welded using all conventional welding techniques however special attention must be given while welding this material since improper welds may lead to cracking during operation due to lack of fusion between base material and filler metal . Preheat should also be used before welding if necessary so that localized melting does not occur, leading to poor fusion between base material and weld filler metal.


In conclusion, alloy steel grade CM 75 is an excellent choice for any application where strength , durability ,corrosion resistance , heat resistance & wear resistance are required . Its unique combination of chemical & physical properties make it suitable for many industries ranging from automotive to aerospace & mining sectors. Its machinability &

weldability allow it to be easily molded into complex shapes needed for specific components thus making it an invaluable material choice for many industrial applications worldwide

Related Post