303 stainless steel with great hardness

Hardness said material's ability to fight a hard object into its surface. It is one of the important performance index of metal materials. Generally, the higher the hardness, wear resistance, the better. Commonly used hardness index have brinell, rockwell and vickers hardness. 1. Brinell hardness ( HB） At a certain load ( General 3000 kg) To a certain size ( To 10 mm in diameter) Hardened steel ball pressure into the material surface, keeping a period of time, to load, load with indentation area ratio, is the brinell hardness number ( HB) , the unit is kg force/was ( N/mm2) 。 2. Rockwell hardness ( HR） When HB> 450 or sample hours, brinell hardness test and will not be used to switch to rockwell hardness measurement. It is with a diamond cone apex Angle 120 ° or diameter of 1. 59, 3. 18 mm steel ball, under certain load down into the material surface under test, the hardness of materials by indentation depth. According to different experimental material hardness, the three kinds of different Pi soil building Xing jing? HRA: is 60 kg load and drill coup-de-point forcer for hardness, used in high hardness materials ( Such as cemented carbide, etc. ) 。 HRB, is to use 100 kg load and the diameter of 1. 58 mm hardened steel, hardness, low hardness material ( Such as annealing steel, cast iron, etc. ) 。 HRC: is a 150 kg load and drill coup-de-point forcer for hardness, used in high hardness materials ( Such as hardened steel, etc. ) 。 3 vickers hardness ( HV） To within 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 value, is the vickers hardness values ( HV) 。 Hardness test is the most simple mechanical performance test of a kind of test method. In order to use hardness test instead of some mechanical performance test, the production need a more accurate hardness and strength of the conversion relation. Practice has proved that all kinds of metal material hardness value, between hardness values with approximate the corresponding relationship between and the intensity value. Because of the hardness value is the initial plastic deformation resistance and continue to plastic deformation resistance, the higher the strength of the material, the plastic deformation resistance is higher, the higher the hardness value.