Experiments som hardness test
- 1. Experiments •Hardness test of mild steel using Rockwell Hardness test •Hardness test of mild steel using Brillnell Hardness Test •Determination of Vickers hardness numbers for mild steel •To conduct torsion test on mild steel on cast iron specimens to find out modulus of rigidity. •To determine Young’s Modulus of elasticity of material of beam simply supported at ends. •To conduct shear test on specimen under double shear.
- 2. Experiment no:- 5 AIM: Hardness Test of mild steel Object: To determine the hardness of the given specimen using Rockwell Hardness Test. Specimen and equipments:- Rockwell Hardness testing machine Black Diamond cone indenter Hard Steel specimen
- 3. Setup:- Rockwell Hardness Testing Machine
- 5. Precautions:- Thickness of the specimen should not be less than 8 times the depth of indentation to avoid the deformation to be extended to the opposite surface of specimen. Indentation should not be made nearer to the edge of a specimen to avoid unnecessary concentration of stresses. In such cases distance from the edge to the center of indentation should be greater than 2.5 times diameter of indentation. Rapid rate of applying load should be avoided.
- 6. Experiment no:- 6 AIM: Hardness Test of Mild Steel. Object: To determine the hardness of the given specimen using Brinell Hardness test. Specimen and Equipments:- Brillnell hardness tester Aluminum specimen Ball indenter
- 7. Setup:- Brinell Hardness Test Equipment
- 9. Precautions:- Thickness of the specimen should not be less than 8 times the depth of indentation to avoid the deformation to be extended to the opposite surface of specimen. Indentation should not be made nearer to the edge of a specimen to avoid unnecessary concentration of stresses. In such cases distance from the edge to the center of indentation should be greater than 2.5 times diameter of indentation. Rapid rate of applying load should be avoided. Surface of the specimen is well polished, free from oxide scale and any foreign material.
- 10. Experiment no:- 6 AIM: Hardness Test of Mild Steel. Object: To determine the vickers Hardness numbers for mild steel materials. Specimen and Equipments:- Hardness testing machine Portable microscope
- 11. About the experiment The Vickers hardness test method consists of indenting the test material with a diamond indenter, in the form of a pyramid with a square base and an angle of 136 degrees between opposite faces subjected to a test force of between 1gf and 100kgf. The full load is normally applied for 10 to15 seconds. The two diagonals of the indentation left in the surface of the material after removal of the load are measured using a microscope and their average calculated. The area of the sloping surfaces of the indentation is calculated. The Vickers hardness is the quotient obtained by dividing the kgf load by the square mm area of indentation. When the mean diagonal of the indentation has been determined the Vickers hardness may be calculated from the formula.
- 12. The impression
- 13. Formula used:-
- 14. precautions While selecting the proper load combination, weight of pass should be taken into account. Surface of specimen must be free from impression oxides and scale and should have approximate mirror polish. Load axis should be normal to surface. Thickness should be 1.5 times length of diagonal of impression. Indentation should not be made nearer to the edge of a specimen to avoid unnecessary concentration of stresses.