JB/T 6571-1993 人造金刚石或立方氮化硼冲击韧性测定方法

中华人民共和国机械行业标准人造金刚石或立方氮化硼JB/T6571-93冲击韧性测定方法1主题内容与适用范围本标准规定了人造金刚石或立方氮化硼冲击韧性的测定装置与测定方法。本标准适用于粒度为16/18~270/325的人造金刚石或立方氮化硼冲击韧性的测定。2引用标准GB308滚动轴承钢球GB6406.1人造金刚石或立方氮化硼粒度及其组成GB6406.2人造金刚石或立方氮化硼粒度组成检验方法3木语3.1冲击频率冲击韧性测定仪的电动机单位时间内的转数,r/min3.2冲击次数试样经受冲击时,电动机旋转的转数3.3未破碎率试样按规定冲击频率,经受一定冲击次数,并按规定条件筛分后,筛上物质量与原始质量之比,以百分数表示。3.4冲击韧性未破碎率为50%时的冲击次数,又称半破碎次数4方法概要取一定量超硬磨料基本粒,连同钢球-起装入试样管,冲击后求得破碎率。以未破碎率为50%时的冲击次数表征样品的冲击韧性。5设备5.1CYCJ-91A型冲击韧性测定仪。5.1.1冲击频率:冲击频率自0~2400r/min连续可调。5.1.2试样管:长37mm,内径15mm;材质:不锈钢,两端盖内表面为圆弧凹面5.1.3硬质合金片:试样管内一端衬垫用,材料:YG8。5.1.4钢球:应符合GB308规定,直径8mm(质量2.08~2.09g),精度10级,材质GCr15,硬度62~66HRC。5.1.5试样管、硬质合金片、钢球和端盖的装配如下图:中华人民共和国机械工业部1993-03-31批准1994-01-01实施JB/T6571-93硬质合金片钢球试样管5.2筛机和虮5mm检验筛应符合GB6406.2规定5.3天平:分度值0.1mg6试样制备6.1待测试样粒度组成应符合GB6406.1规定6.2按GB6402.2规定进行筛分,取基本粒作为待测试样,置于110℃士5C的烘箱中烘干1h,取出,放入千燥器中冷却至室温备用7环境条件相对湿度:45%~55%温度:20~25C。8测定方法81将“频率调节”旋钮反时针旋转至0位,接通电源预热15min。8.2调节冲击频率将空试样管固紧于试样支架上,调节冲击频率为2000r/min8.3新钢球打毛新钢球使用前,用酒精擦洗晾干后,将其放入未装硬质合金垫片的试样管内,并装入约0.5g金刚石,冲击2000次。8.4预设半破碎次数预计试样的半破碎次数,并将其设定于“次数设定”拨盘上8.5冲击试样8.51称量;称量试样的质量,精确至0.1mg。试样质量应为0.4+8m20g。852将试样连同钢球…起装入一端带有硬质合金垫片的试样管内,牢固地装于试样支架上,启动仪器冲击试样。8.5.3在冲击试样过程中,冲击频率偏离预定值应小于10r/min。冲击试样时允许微调“频率调节”旋钮,使冲击频率回到预定值。8.6筛分选用较原试样粒度号细一号的基本粒筛网将冲击后试样筛分3min。例1:原试样粒度号为70/80,用网孔尺寸为181Pm的筛网取基本粒作为试样,冲击后选用网孔尺寸应为151;m的筛网。例2:原试样粒度号为40/50,用网孔尺寸为302m的筛网取基本粒作为试样,冲击后选用网孔尺寸应为255m的筛网。8.7求未破碎率JB/T6571-93称量筛上物,求出未破碎率,精确至小数点后一位8.8近测试求出的未砹碎率应在47%~53%范围内(含47%和53%下同),否则重新设定冲击次数,并按规定冲击频率和重设冲击次数冲击另一份试样,直至未破碎率落在规定范围内。重设冲击次数按下式计算:T=mT1…s…………(1)式中:T—重设冲击次数,次;T1—试验采用的冲击次数,次;m—试样经T次冲击后求得的未破碎率所对应的逼近系数,遇近系数值见附录A(补充件)例:原设定冲击次数为2500次,冲击后求得未破碎率为64.3%,查附录A对于未破萨率64.3的逼近系数为1.570,由式(1)得T为3925次。9计算经过通近测试未破碎率已在47%~53%范围内,再根据该未破碎率及其对应的冲击次数,按式(1)计算得出的冲击次数即为样品的冲击韧性值。0误差同一个试样,未破碎率测试的标准误差应小于士1.00(%)。11一最要求11.1人造金刚石测试时,一个钢球允许累计冲击次数12000次,试样管内硬质合金垫片单面允许累计冲击次数24000次;立方氯化硼测试时,钢球允许累计冲击次数20000次,硬质合金垫片单面允许累计冲击次数40000次;试样管内径超过16mm时,连同端盖同时更换。11.2同一个试样在测试过程中应使用同一个钢球。12仲检验仲裁检验时,同一试样应做3次试验,取半破碎次数3次试验的平均值作为结果。24JB/T6571-93附录A近系数(补充件)A1逼近系数见表A1表A1未碱碎率,%0.00,1t.20.30.40.50.60.80.9200.4310.43210.433{0.43510.436{0.4370.4390.4400.410.443210.440.4450.4470.4480.4500.4510.4520.454}0.4550.456220.4580.4590.4610.4620.463}0.4650.460.4670.4690.470230.4720.4730.474}0.4760.4770.4790.4800.4810.4830.484240.4860.48?0.4890.4900.4910.4930.4940.4964970.499250.5000.5010.5030.5040.506「0.5070.5090.5100.5120.513260.5150.5165180.5190.5200.5220.5230.5250.5260.528270.5290.5310.5320.5340.5350.53?0.5380.5400.5410.543280.5450.5460.5480.5490.5510.5520.5540.5550.5570.558290.5600.5620.5630.5650.5660.5680.5690.5710.5730.574300.576}0.577}0.5790.5810.5820.5840.5850.5870.5890.590310.5920.5930.5950.5970.5980.6000.6020.6030.6050.607320.6080.6100.6120.6130.6150.6170.6180.6200.6220.624330.6250.6270.6290.6300.6320.6340.6360.6370.6390.641340.6430.6440.6460.6480.6500.6510.6530.6550.65765806600.6620.6640.6660.6670.6690.6710.6730.6750.677360.6780.6800.6820.6840.6860.6880.6900.6910.6930.695370.6970.6990.7010.7030.050.7070.7090.7110.7120.714380.7160.7180.7200.1220.7240.7260.7280.7300.7320.7340,7360.7380.740.7420.7440.746{0.7480.7500.7520.754400.7560.7590.7610.7630.7650.7670.7690.7710.730.75410.770.7800.7820.7840.7860.7880.7900.7920.7950.797420.7990.8010.8030.8060.8080.8100.8120.8150.8170.819430.8210.8230.8260.8280.8300.8330.8350.8370.8400.842440.8440.8470.8490.8510.8540.8560.8580.8610.8630.86450.8680.8700.8730.8750.8780.8800.8830.880.880.890460.8930.8950.8980.9000.9030.9050.9080.9100.9130.915170,9180.9210.9230.9260.9280.9310.9340.9360.9390.942480.9440.9470.9500.9520,950.9580.9610.9630.9660.9690.9720.9770.9809.9830.9860.9890.9910.9940.99725JB/T657193表A1(完未破碎率,%0.00.10,20.40.50.60.70.80.9501.0001.003}1.061.0091.0121.0151.0181.0201.0231.026511.0291.0321,0351.0381.0411.041.0481.0511.054{1.059521.0601.06311.066(1.0691.073}1.0761.0791.0821.085{1.088531.0921.0951.0981.1021.1051.1081.11l}1,1151,18}1.122541.1251.1281.1321.1351.1391.1421.1451:.1491.1521.156551.1591.1631.1671.101.1741.1771.1811.1841.1881.1921.19511.1991.203}1.2071.2101.2141.2181.2221.2251.229571.2331.2371.2411.2451.2491.2531.2571.2601.2641.2681.272{1.2771.2811.2851.2891.2931.2971.3011.3051.309591.314{1.3181.3221.3261.3311.351.3391.3441.3481.352601.357}1.3611.3661.3701.3751.3791.3841.388}1.3931.398611.4021.4071.4121.4161.4211.4261.4311.4351.4401.4451.4501.4551.4601.4651.4701.4751.4801.4851.4901.495631.5001.5051.5111.5161.5211.5261.5321.5371.5421.5481.5531.581.5641.5701.5751.5811.5861.5921.5981.603651.6091.6151.6211.6261.6321.6381.644{1.6501.6561.662661.6681.6741.6801.6871.6931.6991.705}1.7121.718{1.724671.73]1.737{1.7441.7501.7571.7641.7701.7771.7841.790681.7971.8041.8111.8181.8251.8321.8391.8463.8541.861691.8681.875{1.8831.890{1.89811.9051.9131.9201.9281.936701.9431.9511.9591.9671.9751.98311.9911.9992.072.0167120242.0322.0412.0492.0582.0662.0752.0842.09221017221102.1192.12821372.1462.1552.1652.17421832.1732,2022.2122.2222.2322.2412.2512.2612.2712.2822.292742.3022.3122.323}2.3332.342.3552.3652.3762.387239852.4092.4212.4322.4432.4552.4662.4782.4902.5022.5142.5262.5382.5502.5622.5752.5882.6002.6132.6262.639772.6522.6652.6792.6922.7062.7192.7332.7472.761275782.7902.8042.8192.8342.848(2.8632.8782.894}2.9092925792.941(2.9562.9722.9893.005{3.0213.0383.05513.0723.089附加说明本标准由机槭工业部郑州磨料磨具磨削研究所提出并归口。本标准由郑州磨料磨县磨削研究所负责起草本标准主要起草人田松乔、张骏祥。