The hardness of the material

Local resistance material hard objects the ability referred to as the hardness of its surface.Test the steel hardness is the most common method is to use file file to wipe on the edge of the workpiece, by its surface scratch depth is presented to determine the hardness of high and low.This method is called file test this method is not scientific.With hardness tester to test more accurate, but also the modern test hardness of the commonly used method.The commonly used hard. Method to measure brinell, rockwell hardness and vickers hardness testing methods, such as hardness is an important measure of degree of hard nd soft metal materials performance metrics, it can be understood as the material the ability of resistance to elastic deformation and plastic deformation or damage, can also be expressed as the material's ability to fight the residual deformation and failure.Hardness is not a simple physical concept, but the material mechanical properties such as elasticity, plasticity, strength and toughness of the composite indicator.Hardness test according to the different test methods can be divided into static pressure method (such as brinell, rockwell hardness vickers hardness, etc.), scratch method (such as mohs hardness), rebound method (e.g., shore hardness) and microhardness, a variety of methods such as high hardness.Brinell hardness to HB [N] (KGF/was) said (HBS \ HBW) production of cloth hardness were determined after the annealing, normalizing and tempering was just a, and cast iron, non-ferrous metals, such as low alloy structural steel wool embryo or hardness of semi-finished products.Rockwell hardness can be divided into the HRA, HRB, HRC, HRD. Four, and their measuring range and application range are also different.As a production of HRC used most frequently.Indentation is small, measurable thinner material, the hardness of hard materials and finished products.Vickers hardness In order to HV said.Metal Hardness (Hardness), code-named H.By different method of hardness test, the conventional said brinell (HB) and rockwell (HRC), vickers's (HL) hardness (HV), etc, among them with HB and HRC is more commonly used.HB has a wide application range, HRC is suitable for the surface of high hardness materials, such as heat treatment hardness, etc.The difference is that a probe different hardness tester, brinell hardness tester measuring head of steel ball, and the measurement of rockwell hardness tester for diamond.HV - suitable for microscopic analysis.Vickers hardness (HV) to 120 kg load and apex Angle of 136 ° diamond square forcer pressure cone into the surface of materials, materials of the indentation indentation surface area divided by load values, i.e., for the vickers hardness (HV) values.HL portable hardness tester, easy to measure, after using the impact ball head impact surface hardness, produce bounce.Using the punch at 1 mm from the sample surface of rebound velocity and the ratio of impact velocity calculated hardness, formula: hardness on the Richter scale = 1000 x VB (rebound)/HL VA (impact speed).A portable hardness tester with magnitude on the Richter scale (HL) measurement can be converted into: after brinell (HB) and rockwell (HRC), vickers (HV), shore hardness (HS).Or directly with measuring principle with cloth's (HB) and rockwell (HRC), vickers (HV), (HL), the shore on the Richter scale (HS) measuring hardness value. 

HB - brinell hardness;Brinell hardness (HB) commonly used for soft materials, such as non-ferrous metal, before or after the annealing heat treatment of steel.Rockwell hardness (HRC) is commonly used in high hardness materials, such as the hardness after heat treatment and so on.

Cloth type hardness (HB) is based on a certain size of test load, to a certain diameter of hardened steel or hard alloy ball pressure into the metal surface to be tested, keep time, and then unloading, measured surface indentation diameter measurement.Cloth type divided by indentation hardness value is a load of spherical surface area of the quotient.Is commonly: at a certain load (3000 kg) usually put a certain size (10 mm in diameter) of a hardened steel ball pressure into the material surface and stay for a period of time, to load, load with indentation area ratio, is the brinell hardness number (HB), the unit is kg force/was (N/was).

Los type is the indentation hardness depth of plastic deformation to determine the hardness value indicators.At 0.002 mm as a unit of hardness.When HB > 450 or sample hours, brinell hardness test and will not be used to switch to rockwell hardness measurement.