Technical Data

Metallurgical Terms

Brinell Hardness Test.

The method consists of indenting the metal with a 10mm diameter steel ball subjected to a load of 3,000 kg. For non-ferrous metal, the load is reduced. The load is applied for 10 to 15 seconds, after which it is removed; the diameter of the recovered indentation is measured and the Brinell Hardness Number is calculated by dividing the load applied (kilogrammes) by the superficial area of the depression caused by the hard steel ball (in square millimetres).

Brittle Fracture.

(See Fracture).

Burden.

The ratio of the total weight of the ore and flux to the fuel charged into a blast furnace. A heavy burden is one with a high ration of ore to coke.

Burnt Steel.

The term is usually applied to a condition in which visible oxide films are formed at the crystal boundaries of the steel. This denotes that the steel has been heated almost to the solidus temperature and is, therefore, permanently damaged. (See Overheating).