Skip to main content

Brinell hardness tester procedure.

Brinell hardness tester procedure:-

BRINELL HARDNESS TESTING

The Brinell hardness test is used for larger samples in materials with a coarse or inhomogeneous grain structure. This page describes the Brinell hardness test in detail and gives you practical information on how to apply it.


Brinell Test Machine Description:-

  1. The Brinell Hardness Tester consists of a loading system, the main screw, and a dial gauge.
  2. The loading system consisting of weights, leavers and a hydraulic dashpot and a plunger arrangement is enclosed in the cast iron body of the machine.
  3. The main screw is also protected from extraneous elements by a rubber bellow.
  4. It carries the test table on its top to hold the specimen and is actuated by a hand at the base.
  5. The machine is provided with two ball indenters (of sizes 2.5mm&5mm) to transmit the test load on to the specimen

DEFINITION OF THE BRINELL HARDNESS TEST:-

Today, the Brinell test is performed using a Brinell hardness test unit. The machine presses a tungsten carbide ball into the sample, and then optically measures the diameter of the impression.
  • Indenter sizes: 1, 2.5, 5 and 10 mm
  • Loads: From 1 kgf to 3000 kgf
  • Maximum hardness: 650 HBW

The Brinell hardness test method as used to determine Brinell hardness, is defined in ASTM E10. Most commonly it is used to test materials that have a structure that is too coarse or that have a surface that is too rough to be tested using another test method, e.g., castings and forgings. Brinell testing often use a very high test load (3000 kgf) and a 10mm diameter indenter so that the resulting indentation averages out most surface and sub-surface inconsistencies.
Common test forces range from 500kgf often used for non-ferrous materials to 3000kgf usually used for steels and cast iron. There are other Brinell scales with load as low as 1kgf and 1mm diameter indenters but these are infrequently used. 


Test Method Illustration 

D = Ball diameter 
d = impression diameter 
F = load 
HB = Brinell result 

Test Procedure

  1. The surface of the test specimen must be either machined, ground, lapped or polished.
  2. Set the machine to the required stage of the test load.
  3. Choose the indentor to be used and fasten it to the machine.
  4. Place the specimen on the test table and, apply a minor load of 10-kg-f on it by turning the hand wheel and bringing both the pointers on the dial gauge to the ‘set’ positions.
  5. Apply the major load (remaining part of the test load) on the specimen by turning the loading lever backward.
  6. Maintain the load on the specimen exactly for the specified dwell time (15 seconds) and then release it by turning the loading lever forwards.
  7. Take out the specimen and measure the diameter of the indentation formed on it by using the Brinell Microscope..

Comments

Popular posts from this blog

INCLUSION RATING TESTING

INCLUSION RATING TESTING:- Non-metallic inclusions process :- Non-metallic inclusions are chemical compounds and non metals that are present in steel and other alloys. They are the product of chemical reactions, physical effects, and contamination that occurs during the melting and pouring process. Sources of inclusions formation Non-metallic inclusions that arise because of different reaction during metal production are called natural or indigenous. They include oxide , sulfide , alumina silicate and Globular oxide .Singl Globular oxide Apart from natural inclusions there are also parts of Slag, refectories , material of a casting mould (the material the metal contacts during production) in the metal. Such non-metallic inclusions are called foreign, accidental or exogenous. Most inclusions in the reduction smelting of metal formed because of admixture dissolubility decreasing during cooling and consolidation. Non-metallic...

Heat treatment process.

Heat Treatment Processes:- Heat treatment of  steels is the heating and cooling of metals to change their physical and mechanical properties, without letting it change its shape. improving formability, machining, etc. Heat Treatment Process Steps:- In simple terms, heat treatment is the process of heating the metal, holding it at that temperature, and then cooling it back. During the process, the metal part will undergo changes in its mechanical properties. This is because the high temperature alters the microstructure of the metal. And microstructure plays an important role in the mechanical properties of a material. Holding:- During the holding, or soaking stage, the metal is kept at the achieved temperature. The duration of that depends on the requirements. For example, case hardening only requires structural changes to the surface of the metal in order to increase surface hardness. At the same time, other methods need uniform properties. In this case, the holding period is long...

Case Carburizing process.

  Case hardening Process Case hardening is a material processing method that is used to increase the hardness of the outer surface of a metal. Case hardening results in a very thin layer of metal that is notably harder than the larger volume of metal underneath of the hardened layer. - It is mainly used on low-carbon steels. The part is heated to 871–954 °C (1600–1750 °F) - Attempt to harden an entire metal object. One reason is efficiency. Less energy and less time are required to heat the outermost surface of a metal as opposed to its entire cross section. - A hard outside shell and a more ductile interior. What Types of Metals Can Be Case Hardened? Metals that can be case hardened are generally limited to ferrous materials, although there are special cases such as the Nitriding of some titanium or aluminum alloys. The ferrous metals commonly case hardened are. Gears Fasteners Camshafts Rods Pins   --BENEFITS OF CASE HARDENING Creating a more durable product Increases wea...