Common terms of the hottest hardware II

Common terms of hardware (II)

Rockwell hardness has many scales, common ones are:

A. scale C: Code HRC, using 1471.1n (150kgf) total load and the hardness obtained by diamond indenter It is suitable for hardness measurement of hardened and tempered steel, quenched steel and other hard materials

b. scale a: Code HRA, hardness obtained by 588.4n (60 KGF) total load and diamond indenter It is suitable for hardness measurement of surface hardened steel, carburized steel or cemented carbide

c. scale B: Code HRB, which ensures the high resolution of the experimental force. If the total negative assumption of 980.7n (100 KGF) is adopted, it must be the ball screw load and the hardness obtained by the quenched steel ball press with a diameter of 1.588mm. It is suitable for hardness measurement of soft materials such as non-ferrous metals, annealed steel and normalized steel

surface Rockwell hardness:

code: HR

unit: none

Introduction: the test principle is the same as Rockwell hardness. It is applicable to the determination of hardness of surface and grade steel sheets and non-ferrous metals treated by carburizing and nitriding on the surface of steel. There are also many scales for this kind of hardness:

A. scale 15N: Code hr15n, the hardness obtained by using 147.1n (15 KGF) total load and diamond indenter

B. scale 30n: Code hr30n, the hardness obtained by using 294.2n (30 KGF) total load and diamond indenter

C. scale 45N: Code hr45n, the hardness obtained by using 441.3n (45 KGF) total load and diamond indenter

D. scale 15t: Code hr15t, Place the oil needle knob with 147.1n (15 KGF) total load and diameter 1 Hardness obtained by 588mm hardened steel ball press

e. scale 30t: Code hr30t, hardness obtained by using 294.2n (30 KGF) total load and 1.588mm diameter hardened steel ball press

f. scale 45t: Code hr45t, hardness obtained by using 294.2n (45 KGF) total load and 1.588mm diameter hardened steel ball press

Vickers hardness:

code: hv

unit: none

introduction: with a load of 49.03~980.7n, Press the square conical diamond with an included angle of 1360 on the opposite surface onto the surface of the material, keep it for a specified time, measure the diagonal length of the indentation, and then calculate the hardness according to the formula. It is applicable to the hardness measurement of larger workpieces and deeper surface layers. Vickers hardness still has small load Vickers hardness, test load 1.961~

common terms?? Strength limit (strength)

code:; Unit: MPa (or n/mm2)

introduction: refers to the maximum ability of metal materials to resist the destructive effect of external forces. Strength is divided into:

compressive strength: Code BC, refers to the strength limit when the external force is pressure

bending strength: Code BB, refers to the strength limit when the external force is perpendicular to the material axis and makes the material bend after the action

shear strength: Code C, refers to the external force is perpendicular to the material axis, safety helmet impact resistance testing machine precautions, and the strength limit when the material is sheared