硬度换算公式.doc

硬度换算公式: 1.肖氏硬度(HS)=勃式硬度(BHN)/10+122. 肖式硬度(HS)=洛式硬度(HRC)+153.勃式硬度(BHN)= 洛克式硬度(HV)4.洛式硬度(HRC)= 勃式硬度(BHN)/10-3-一、硬度简介： 硬度表示材料抵抗硬物体压入其表面的能力。它是金属材料的重要性能指标之一。一般硬度越高，耐磨性越好。常用的硬度指标有布氏硬度、洛氏硬度和维氏硬度。1.布氏硬度(HB) (Brinell)以一定的载荷(一般3000kg)把一定大小(直径一般为10mm)的淬硬钢球压入材料表面，保持一段时间，去载后，负荷与其压痕面积之比值，即为布氏硬度值(HB)，单位为公斤力/mm2 (N/mm2)。 2.洛氏硬度(HR)当HB450或者试样过小时，不能采用布氏硬度试验而改用洛氏硬度计量。它是用一个顶角120的金刚石圆锥体或直径为1.59、3.18mm的钢球，在一定载荷下压入被测材料表面，由压痕的深度求出材料的硬度。根据试验材料硬度的不同，分三种不同的标度来表示： HRA：是采用60kg载荷和钻石锥压入器求得的硬度，用于硬度极高的材料(如硬质合金等)。 HRB：是采用100kg载荷和直径1.58mm淬硬的钢球，求得的硬度，用于硬度较低的材料(如退火钢、铸铁等)。HRC：是采用150kg载荷和钻石锥压入器求得的硬度，用于硬度很高的材料(如淬火钢等)。3 维氏硬度(HV)以120kg以内的载荷和顶角为136的金刚石方形锥压入器压入材料表面，用材料压痕凹坑的表面积除以载荷值，即为维氏硬度HV值(kgf/mm2)。 注：洛氏硬度中HRA、HRB、HRC等中的A、B、C为三种不同的标准，称为标尺A、标尺B、标尺C。 洛氏硬度试验是现今所使用的几种普通压痕硬度试验之一，三种标尺的初始压力均为98.07N(合10kgf)，最后根据压痕深度计算硬度值。标尺A使用的是球锥菱形压头，然后加压至588.4N(合60kgf)；标尺B使用的是直径为1.588mm(1/16英寸)的钢球作为压头，然后加压至980.7N(合100kgf)；而标尺C使用与标尺A相同的球锥菱形作为压头，但加压后的力是1471N(合150kgf)。因此标尺B适用相对较软的材料，而标尺C适用较硬的材料。 实践证明，金属材料的各种硬度值之间，硬度值与强度值之间具有近似的相应关系。因为硬度值是由起始塑性变形抗力和继续塑性变形抗力决定的，材料的强度越高，塑性变形抗力越高，硬度值也就越高。但各种材料的换算关系并不一致。本站硬度对照表一文对钢的不同硬度值的换算给出了表格，请查阅。二、硬度对照表：根据德国标准DIN50150,以下是常用范围的钢材抗拉强度与维氏硬度、布氏硬度、洛氏硬度的对照表。抗拉强度RmN/mm2维氏硬度HV布氏硬度HB洛氏硬度HRC 硬度知识硬度试验是机械性能试验中最简单易行的一种试验方法。为了能用硬度试验代替某些机械性能试验，生产上需要一个比较准确的硬度和强度的换算关系。实践证明，金属材料的各种硬度值之间，硬度值与强度值之间具有近似的相应关系。因为硬度值是由起始塑性变形抗力和继续塑性变形抗力决定的，材料的强度越高，塑性变形抗力越高，硬度值也就越高。下面是本站根据由实验得到的经验公式制作的快速计算器，有一定的实用价值，但在要求数据比较精确时，仍需要通过试验测得。三、硬度換算公式1.肖氏硬度(HS)=勃式硬度(BHN)/10+12 2.肖式硬度(HS)=洛式硬度(HRC)+15 3.勃式硬度(BHN)= 洛克式硬度(HV) 4.洛式硬度(HRC)= )= 勃式硬度(BHN)/10-3HBS (Hardness, Brinell, Steel) or the HBW (Hardness, Brinell, Tungsten )肖氏硬度 Shore Hardness (邵氏硬度)布氏硬度Brinell Hardness (勃氏硬度)摩氏硬度表 Mohs Hardness Scale 莫氏硬度表Mohs Hardness Scale 奧地利礦物學家莫氏(Frederich Mohs)建立的硬度表，作為礦物硬度的標準。奥地利矿物学家莫氏(Frederich Mohs)建立的硬度表，作为矿物硬度的标准。 最軟者為滑石talc，最硬者為鑽石石diamond，共十種分十級。最软者为滑石talc，最硬者为钻石diamond，共十种分十级。 （1）滑石(Talc) （2）石膏(Gypsum) （2）石膏(Gypsum) （3）方解石(Calcite) （3）方解石(Calcite) （4）螢石(Fluorite) （4）萤石(Fluorite) （5）磷灰石(Apatite) （5）磷灰石(Apatite) （6）正長石(Orthoclase) （6）正长石(Orthoclase) （7）石英(Quartz) （7）石英(Quartz) （8）黃玉(Topaz) （8）黄玉(Topaz) （9）剛玉(Corundum) （9）刚玉(Corundum)（10）鑽石(Diamond) （10）钻石(Diamond)The Rockwell scale is a hardness scale based on indentation hardness of a material. The Rockwell test determines the hardness by measuring the depth of penetration of an indenter under a large load compared to the penetration made by a preload. There are different scales, denoted by a single letter, that use different loads or indenters. The result is a dimensionless number noted as HRA, where A is the scale letter.When testing metals, indentation hardness correlates linearly with tensile strength. This important relation permits economically important nondestructive testing of bulk metal deliveries with lightweight, even portable equipment, such as hand-held Rockwell hardness testers.OperationForce diagram of Rockwell testThe determination of the Rockwell hardness of a material involves the application of a minor load followed by a major load, and then noting the depth of penetration from a dial, on which a harder material gives a higher number. The chief advantage of Rockwell hardness is its ability to display hardness values directly, thus obviating tedious calculations involved in other hardness measurement techniques.It is typically used in engineering and metallurgy. Its commercial popularity arises from its speed, reliability, robustness, resolution and small area of indentation.In order to get a reliable reading the thickness of the test-piece should be at least 10 times the depth of the indentation. Also, readings should be taken from a flat perpendicular surface, because convex surfaces give lower readings. A correction factor can be used if the hardness of a convex surface is to be measured.Scales and valuesThere are several alternative scales, the most commonly used being the B and C scales. Both express hardness as an arbitrary dimensionless number.Various Rockwell scalesScaleAbbreviationLoadIndenterUseAHRA60 kgf120 diamond coneTungsten carbideBHRB100 kgf116-inch-diameter (1.588 mm) steel sphereAluminium, brass, and soft steelsCHRC150 kgf120 diamond coneHarder steels B100DHRD100 kgf120 diamond coneEHRE100 kgf18-inch-diameter (3.175 mm) steel sphereFHRF60 kgf116-inch-diameter (1.588 mm) steel sphereGHRG150 kgf116-inch-diameter (1.588 mm) steel sphereAlso called a brale indenter Except for testing thin materials in accordance with A623 the steel indenter balls have been replaced by tungsten carbide balls of the varying diameters. When a ball indenter is used, the letter W is used to indicate a tungsten/carbide ball was used, and the letter S indicates the use of a steel ball. E.g.: 70 HRCW indicates the reading was 70 in the Rockwell C scale using a Tungsten/Carbide indenter.The superficial Rockwell scales use lower loads and shallower impressions on brittle and very thin materials. The 45N scale employs a 45-kgf load on a diamond cone-shaped Brale indenter, and can be used on dense ceramics. The 15T scale employs a 15-kgf load on a 116-inch-diameter (1.588 mm) hardened steel ball, and can be used on sheet metal.Readings below HRC 20 are generally considered unreliable, as are readings much above HRB 100.Typical values Very hard steel (e.g. chisels, quality knife blades): HRC 5566 ( Hardened High Speed Carbon and Tool Steels such as M2, W2, O1, CPM-M4, and D2, as well as many of the newer powder metallurgy Stainless Steels such as S30V, 154CM, ZDP-189, etc. ) Axes: about HRC 45-55 Brass: HR