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1、一、里氏硬度计测试基本原理随着单片技术的发展，1978年，瑞士人Leeb博士首次提出了一种全新的测硬方法，它的基本原理是具有一定质量的冲击体在一定的试验力作用下冲击试样表面，测量冲击体距试样表面Imm处的冲击速度与回跳速度，利用电磁原理，感应与速度成正比的电压。里氏硬度值以冲击体回跳速度与冲击速度之比来表示。计算公式：HL=I000*(VB/VA)式中：HL里氏硬度值VB冲击体回跳速度VA冲击体冲击速度二、里氏硬度计冲击装置里氏硬度度有D、DC、D=I5、C、G、E、DL七种：D：外型尺寸：f20*70mm,重量：75g.通用型，用于大部分硬度测量。DC：外型尺寸：f20*86mm,重量：50
2、g。冲击装置很短，主要用于非常局促的地方，例如孔或圆筒内。D+15：外型尺寸：f20*162mm,重量：80g。头部细小，用于沟槽或凹入的表面硬度测量。C：外型尺寸：f20*141mm,重量：75g。冲击能量最小，用于测小轻、薄部件及表面硬化层。G：外型尺寸：f30*254mm,重量：250g0冲击能量大，对测量表面要求低。用于大、厚重及表面较粗糙的锻铸件。E：外型尺寸：f20*162,重量80g压头为人造金刚石，用于硬度极高材料的测定。DL：外形尺寸：f20*202mm,重量：80g头部更加细小，用于狭窄沟槽及齿轮面硬度的测定。三、异型支撑环的使用在现场工作中，经常遇到曲面试件，各种曲面对硬
3、度测试结果影响不同，在正确操作的情况下，冲击落在试件表面瞬间的位置与平面试件相同，故通用支撑环即可。但当曲率小到一定尺寸时，由于平面条件的变形的弹性状态相差显著会使冲击体回弹速度偏低，从而使里氏硬度示值偏低。因此对试样，建议测量时使用小支撑环。对于曲率半径更小的试样，建议选用异型支撑环。四、里氏硬度计的测量范围根据里氏原理，只要材料具备一定刚性，能形成反弹，就能测出准确的里氏硬度值，但很多材料里氏与其它制式的硬度没有相应的换算关系，因此里氏硬度计目前只装了9种材料的换算表。具体材料如下：钢和铸钢，合金工具钢，灰铸铁，球墨铸铁，铸铝合金，铜锌合金，铜锡合金，纯铜，不锈铜。对于些特殊材料的试样，用
4、户可使用公司提供的拟合曲线软件做专用换算表。在实际生产中，使用的金属材料多种多样，由于里氏硬度计对材料的加工方式、材料的合金元素组成敏感，而里氏硬度计芯片中储存的硬度换算表不可能都满足用户的需要，用户在测试中，可以使用拟合软件做自己专用的硬度换算表。五、影响里氏硬度计测试精度的因素1、数据换算产生的误差里氏硬度换算为其它硬度时的误差包括两个方面：一方面是里氏硬度本身测量误差，这涉及到按方法进行试验时的分散和对于多台同型号里氏硬度计的测量误差。另一方面是比较不同硬度试验方法所测硬度产生的误差，这是由于各种硬度试验方法之一间不存在明确的物理关系，并受到相互比较中测量不可靠影响的原因。2、特殊材料引
5、起的误差存贮在硬度仪中的换算表对下列钢种可能产生偏差：所有奥氏体钢耐热工具钢和莱氏体铝钢（工具钢类）硬质材料会引起弹性模量增加，从而使L值偏低。这类钢应在横截面上进行测试局部冷却硬化会引起L值偏高磁性钢由于磁场影响，会使L值偏低。表面硬化钢，基体软，会使L值偏低，当硬化层大于0.8mm时（C型冲击装置为0.2mm）则不影响L值。3、齿轮检测中的误差一般情况下，由于齿面较小，测试误差相对较大，对此，用户可根据情况设计相应的工装，将有助于减小误差。4、材料弹性、塑性的影响里氏值除与硬度、强度相关外，更与弹性模量有关，硬度值是材料硬度和塑性的特征参数，因为两者的成分必然是共同测定的。在弹性部分，首先
6、明显受E模量影响，在这方面当材料的静态硬度相同，而E值大小不同时，E值低的材料，L值较大5、热轧方向造成的误差当被测工件系热轧工艺成型时，如果测试方向与轧制方向一致，会因弹性模量E偏大而造成测试值偏低，故测试方向应垂直于热轧方向。例如：测圆柱截面硬度时，应在径向测试为好。（一般圆柱热轧方向为轴向）。6、试样重量、粗糙度、厚度的影响7、试件磁性应小于300高斯8、其它因素的影响测量管件硬度时须注意：管件注意稳固支撑，测试点应靠近支撑点且与支撑力平行，管壁较薄在管内放入适当芯子。D型冲击装置里氏硬度换算表(附表B)碳钢，低合金智冈和铸钢(E210OOONZnun)HB(I)HB(2)HLDHRCH
7、RBHV(F=(F=HSD30083HB(1)为轧制材料30284HB(2)为锻造材料304853068530886HLDHRCHRBHV(F=(F=HSD3108731287314883168931890HLDHRCIIRBHV(F=(F=HSD3209032291324923269332894HLDHRCHRBHV(F=(F=HSD3309433295334963369733898HLDHRCHRBHV(F=(F=HSD34099342100344101346101348102HLDHRCHRBHV(F=(F=HSD35059.610335260.31043546110535661.710
8、635862.4107HLDHRCHRBHV(F=(F=HSD36063.110836263.810936464.5HO36665.111136865.8112HLDHRCHRBHV(F=(F=HSD37066.41143726711537467.711637668.311737868.9118HLDHRCHRBHV(F=(F=HSD38069.511938270.112038470.612138671.212338871.8124HLDHRCHRBHV(F=(F=HSD39072.312539272.912639473.41273967412939874.5130HLDHRCHRBHV(F=
9、(F=HSD4007513114240275.51331444047613414540676.513514740877136149HLDIIRCHRBHV(F=(F=HSD41077.51381504127813915241478.414115341678.914215541879.3143156HLDHRCHRBHV(F=(F=HSD42079.814514015742280.214614115942480.714814316042681.114914416242881.5151145163HLDHRCHRBHV(F=(F=HSD43081.915214716543282.415414816
10、643482.815515016843683.215715116943883.6158153171HLDHRCHRBHV(F=(F=HSD4408416015417244284.416115617444484.616315717544685.116415917644885.5166160178HLDHRCHRBHV(F=(F=HSD45085.916816217945286.318916418145486.61711651824568717316718445887.4174168185HLDHRCIIRBHV(F=(F=HSD46087.717617018726.446288.11781721
11、8826.746488.51791731902746688.818117519127.346889.218317719327.6HLDHRCHRBHV(F=(F=HSD47089.518517819427.947289.918618019628.247490.318818219728.547690.619018419828.84789119218520029.1HLDHRCHRBHV(F=(F=HSD48091.319418720229.448291.719518920329.748492.11971912053048692.419919220630.348892.820119420830.6
12、HLDHRCHRBHV(F=(F=HSD49093.120319620930.949293.520519821131.249493.920720021231.549694.320920221431.749894.621120421532HLDHRCHRBHV(F=(F=HSD5009521320521732.250295.421520721932.550495.821720922032.850696.221921122233.150896.622121322433.3HLDHRCHRBHV(F=(F=HSD51019.89722321522533.651220.297.422521722733
13、.951420.697.922721922934.25162198.322922123034.451821.398.723122323234.7HLDIIRCHRBHV(F=(F=HSD52021.799.2233225234355222299.623522723535.352422.423722923735.652622.823923123935.852823.124123424136.1HLDHRCHRBHV(F=(F=HSD53023.524423624236.453223.824623824436.753424.12482402463753624.525024224837.353824
14、.825224425037.6HLDHRCHRBHV(F=(F=HSD54025.225524625237.954225.525724925438.154425.825925125638.454626.226125325838.754826.526425525939HLDHRCHRBHV(F=(F=HSD55026.826625826139.355227.126826026337055427.527026226539.955627.827326526840.255828.127526727040.5HLDHRCHRBHV(F=(F=HSD56028.427826927240.856228.82
15、8027227441.156429.128227427641.456629.428527627841.756829.728727928042HLDHRCHRBHV(F=(F=HSD5703029028128242.357230.329228328542.657430.629428628742.957630.929728828943.257831.229929129243.5HLDHRCIIRBHV(F=(F=HSD58031.530229329443.858231.830429629644.158432.130729829944.458632.430930130144.758832.73123
16、0330445HLDHRCHRBHV(F=(F=HSD5903331530630845.459233.331730831045.759433.63203113134659633.932231431546.359834.232531631846.6HB(1)HB(2)HLDHRCHRBHV(F=(F=HSD60034.532831932046.960234.833032232347.260435.133332432547.560635.433632732847.860835.733833033148.2HLDHRCHRBHV(F=(F=HSD61035.934133233348.561236.2
17、34433533648.261436.534633833949.161636.834934034149.461837.135234334449.7HLDHRCIIRBHV(F=(F=HSD62037.435534634650.162237.635734934950.462437.936035135250.762638.23633543555162838.536635735751.3HLDHRCHRBHV(F=(F=HSD63038.736936036051.7632393723633635263439.337536636652.363639.637736936952.663839.838037
18、137152.9HLDHRCHRBHV(F=(F=HSD64040.138337437453.364240.438637737753.664440.738938038053.964640.939238338354.264841.239538638654.6HLDHRCIIRBHV(F=(F=HSD65041.229838938954.965241.740139239255.26544240439539555.665647240739839855.865842.641140140156.2HLDHRCHRBHV(F=(F=HSD66042.841440440456.566243.14174074
19、0756.966443.442041041057.266643.642341341357.566843.942641741757.9HLDHRCHRBHV(F=(F=HSD67044.142942042058.267244.443342342358.567444.743642642658.967644.943942942959.267845.244243243259.5HLDHRCHRBHV(F=(F=HSD68045.544643543559.968245.744943943960.268446045244244260.568646.245644544560.968846.545944844
20、861.2HLDHRCHRBHV(F=(F=HSD69046.846345145161.66924746645545561.969447.346945845862.269647.547346146162.669847.847646546562.9HLDHRCHRBHV(F=(F=HSD7004848046846863.370248.348347147163.670448.64874744746470648.849147847864.370849.149448148164.6HLDHRCIIRBHV(F=(F=HSD71049.34984854856571249.650148848865.371
21、449.850549149165.771650.15094954956671850.351349849866.4HLDHRCHRBHV(F(FHSD72050.651650250266.772250.852050550567.172451.152450850867.472651.352851251267.872851.653251551568.2HLDHRCHRBHV(F=(F=HSD73051.853551951968.573252.153952252268.973452.354352652669.273652.654752952969.673852.855153353369.9HLDHRC
22、HRBHV(F=(F=HSD74053.155553653670.374253.355954054070.774453.65635435437174653.856854754771.474854.157255155171.8HLDHRCHRBHV(F=(F=HSD75054.357655455472.175254.558055855872.575454.858456156172.97565558956556573.275855.359356956973.6HLDHRCHRBHV(F=(F=HSD76055.55975725727476255.760257657674.3764566065805
23、8074.776656.261058558575.176856.561558758775.5HLDHRCHRBHV(F=(F=HSD77056.761959159175.877256.962459459476.277457.262859859876.677657.46336026027777857.663860560577.4HLDHRCHRBHV(F=(F=HSD78057.964260960977.778258.164761361378.178458.365261761778.578658.665762062078.978858.866262462479.3HLDHRCHRBHV(F=(F
24、=HSD7905966662879.779259.267063280.179459.567663580.579659.768163980.979859.968664381.2HLDHRCHRBHV(F=(F=HSD80060.169164781.480260.46976518280460.670282.480660.870782.88086171283.2HLDHRCHRBHV(F=(F=HSD81061.271883.781261.472384.181461.772884.581661.973484.981862.173985.3HLDHRCHRBHV(F=(F=HSD82062.37458
25、5.782262.575086.182462.775686.582662.97628782863.176887.4HLDHRCHRBHV(F=(F=HSD83063.377387.883263.577988.283463.778588.683663.979189.183864.179789.5HLDHRCHRBHV(F=(F=HSD84064.380389.984264.580990.484464.781690.884664.982291.284865.182891.7HLDIIRCHRBHV(F=(F=HSD85065.383592.185265.484192.685465.68489385
26、665.885493.58586686193.9HLDHRCHRBHV(F=(F=HSD86066.286794.486266.387494.886466.588195.386666.788895.786866.889596.2HLDHRCHRBHV(F=(F=HSD8706790296.787267.290997.187467.391697.687667.592398.187867.693198.6HLDHRCHRBHV(F=(F=HSD88067.8938998826894699.588468.195388668.296188868.4968HLDHRCHRBHV(F=(F=HSD89068.5976
