British Standard Non-alloy and Low Alloy Antifriction Cast Iron Hardness
Introduction
Cast iron is a group of ferrous alloys which are mainly composed of iron and carbon. Different grades are formed through manipulating the carbon and silicon content and the addition of small quantities of other elements such as phosphorous, manganese and sulphur. Cast iron is further divided into either Ni-hard or antifriction or white heart grades. In this article we will discuss British Standard Non-alloy and Low Alloy Antifriction Cast Iron Hardness grades.
Properties
Non-alloy and low alloy antifriction cast iron consists of a white metallic and graphitic alloy, which is mainly composed of approximately 3- 4.2% carbon, up to 0.3% silicon and some small amounts of manganese and sulphur. These grades have good antifriction properties and are used commonly used in rolling gear applications, brake discs, gears and other moving components, being harder and having less friction than plain carbon steels.
This type of cast iron is normally supplied in the as- cast condition and is not heat treated as part of its production process. The hardness of this group of alloys can be increased through heat treatment and a variety of other processes.
British Standard Hardness Grades
The British Standard Non-alloy and Low Alloy Antifriction Cast Iron Hardness grades are denoted by the letters DC or DOfollowed by a letter indicating the hardness. These stand for Ductile Iron Grade and Organically Bonded Iron Grade respectively.
The hardness grades start as low as DC1, with a Brinell Hardness Number (BHN) rating of 200, and go up to DC9, with a BHN rating of 500. The higher the grade, the greater the hardness of the material.
Industries and Applications
Due to the good antifriction properties of the British Standard Non-alloy and Low Alloy Antifriction Cast Iron Hardness grades, they are suitable for many applications, including automotive and machine parts, gears, bearings, brake discs, and other moving parts subject to abrasive wear.
DC1 is suitable for applications that require low wear resistance, such as a cast iron bearing surface. DC2-DC6 grades are typically used for anti-wear applications up to moderate temperatures. Higher grade DC7-DC9 grades are capable of being used in more aggressive applications and are known for their higher wear resistance.
Conclusion
This article has attempted to give a brief overview of the British Standard Non-alloy and Low Alloy Antifriction Cast Iron Hardness grades. This type of cast iron is suitable for a variety of applications in the automotive, machine and other industries. The grades range from DC1 to DC9, with the higher grades having greater hardness and wear resistance.
