利 用正交试验法,通过用CBN刀对GCr15轴承 钢精车切削试验并对试验数据进行了多元线性处理,得出了在此切削条件下的切削用量三因素与刀 具耐用度的Taylor公式,为解决难加工材料GCr15轴承钢的精车及实际生产提供了经验 。关键词CBN刀;精车;正交试验;切削参数中图资料分类号TG5010引言目前加工淬火钢 一般采用磨削工艺,磨削虽可获得高精度与低表面粗糙度的效果,但这种工艺存在生产率较低,加 工费用高,有时表面质量不够理想。特别是轴承厂对轴承内、外圈粗磨时,由于热处理后的变形量 较大,或当操作工人切削用量(尤其是进给量)增大时,可明显提高生产率,但却造成工件的局部 退火烧伤,致使生产出的轴承质量明显下降。随着新型刀具材料的不断出现和发展,淬火钢可用C BN刀具进行切削加工〔1〕,从而为解决难加工材料GCr15轴承套圈的硬态精车,开辟了一 条新的途径。采用首都航天机械公司工具厂生产的CLS-F型立方氮化硼复合聚晶刀具,对GC r15轴承钢外圈进行了精车试验。1试件材料选用GCr15轴承钢(淬火)作为试验用工件材 料,其化学成份如表1。物理机械性能见表2。表1名称含量CSiMnCrNiCuPSGCr 150.95~1.050.15~0.350.20~0.401.30~1.60≤0.30 ≤0.25≯0.027≯0.020表2工件材料热处理状态硬度(HRC)抗拉强度σb(G Pa)延伸率δ(%)冲击值(MJ/m2)导热系数KW/m·℃GCr15淬火60~630 .589~0.71615~250.44140.1由表2可知,该材料硬度高,导热系数小, 属于难加工材料。这将使切削加工时切削力大,切削温度高,力与热集中于刀尖附近,易使刀具磨 损,破损甚至崩刃。故一般刀具材料(H.S.S/Carbides)胜任不了这一切削任务, 选用CBN-H刀具进行切削试验。2试验条件及方案试验设备及试验条件如表3所示。表3机床 CA6140,有可控硅无级调速装置,精度未作调整。工件及尺寸GCr15轴承钢,淬火HR C60-63,130×22轴承外圈。刀具1.材料:DLS-F型CBN-H外圆车刀2. 几何参数:γ0=0°,α0=6°,κr=45°,κ′r=35°,λs=0°,rε=0. 4-0.6。用放大10倍放大镜检验刀刃无缺陷3.刀杆载面尺寸:18×184.刀尖伸出长 度:20切削用量:(2)1.切削速度:v=80-130m/min(n=200-300r /min)。2.进给量:f=0.16-0.20mm/r。3.背吃刀量:ap=0.10- 0.20mm。切削液:无,干切测试仪器:1.2221型压电式表面粗糙度检查仪2.×10 单管显微镜3.秒表采用正交试验法来确定一组合理的切削用量对刀具耐用度的影响〔3〕,为此 ,选用L9(33)正交表来进行表头设计,分别以各因子取值范围的临界值为高水平和低水平, 中间水平(零水平),按下式决定:V0=V+1+V-12=81.7+130.72=106 .2(m/min)f0=f+1+f-12=0.10+0.202=0.15(mm/r)a p0=ap+1+ap-12=0.16+0.202=0.18(mm/r)为使计算简化,进 行如下换算处理:(1)确定各因素的变化范围(见表3)(2)对每个因素的水平进行编码,即 作线性变换,这可使回归计算简化!具体编码见表4。表4水平及符号ap(mm)f(mm/r )v(m/min)上水平+10.100.1681.7零水平00.150.18106.2 下水平-10.200.20130.73试验结果及分析3.1表头设计及试验结果按回归正交 设计原则,试验方案及结果见表5。表5序号.代码.因素apfvRa(μm)T(min)切 削情况及切屑1+1+1+10.726.8切削轻快白色带状屑2+1001.222.5切削 轻快发红变兰带状屑3+1-1-11.319.7切削轻快发红变兰带状屑40+101.42 3.0切削轻快兰色微带火花500-11.520.1切削轻快兰色切削有火花60-1+11 .625.0切削轻快屑兰色带状7-1+1-11.220.4切削轻快屑兰色有火花8-10 +11.325.2切削轻快屑兰色带状9-1-101.421.5切削轻快屑兰色带状CBN -H车刀刃磨后VB=0.01,在实验中每次取相同的磨钝标准VB=0.2mm,为使实测的 数据处理后尽量接近真值,取多次重复实验测量求平均值的方法。3.2切削实验结果的数据处理 为使所测数据可靠,求出每次实验所得标准偏差,并用狄克松检验法将异常数据排除,然后进行多 元回归分析。由T=CT×axp×fy×Vz〔4〕两边取对数,得:lgT=lgG+xlg ap+ylgf-zlgV∴回归值Y=b0+b1x1+b2x2+b3x3y=μ0+b1( x1-x1)+b2(x2-x2)+b3(x3-x3)为简化计算,采用下列模型,即表6序 号ap(mm)f(mm/r)V(m/min)T(min)x1=lgapx2=lgfx3 =lgvy=lgT10.100.1681.726.8-1-0.79601.91221. 428120.100.18106.222.5-1-0.74502.02611.3522 30.100.20130.719.7-1-0.69902.11621.294540.1 50.16106.223.0-0.8240-0.79602.02611.361750. 150.18130.720.1-0.8240-0.74502.11621.303260 .150.2081.725.0-0.8240-0.69901.91221.397970 .200.16130.720.4-0.6990-0.79602.11621.30968 0.200.1881.725.2-0.6990-0.74501.91221.40149 0.200.20106.221.5-0.6990-0.69902.02611.3324 -7.5690-6.720018.163512.1810平均值-0.8410-0.7 4672.01821.3534下面计算ixi1等值:ixi1=-7.5690ix i2=-6.7200ixi3=18.1625ix2i1=6.5027ix2i2= 5.0317ix2i3=36.7197(ixi1)2=57.2898(ixi2) 2=45.1584(ixi3)2=329.9127ixi1xi2=5.6515i xi2xi3=-13.5621ixi3xi1=-15.2755(ixi1)(ix i2)(ixi3)=923.8625iyi=12.1810iy2i=16.504 6{ixi1yi=-10.2489ixi2yi=-9.0988ixi3yi=24 .5505(ixi1)(iyi)=-92.1980(ixi2)(iyi)=-8 1.8563(ixi3)(iyi)=221.2496从而可求出:x1=1nixi 1=-0.8410x2=1nixi2=-0.7467x3=1nixi3=2.018 2y=1niyi=1.3534l11=ix2i1-1n(ixi1)2=0.137 2l12=l21=ixi1xi2-1n(ixi1)(ixi2)=0l13=l31 =ixi1xi3-1n(ixi1)(ixi3)=0l22=ix2i2-1n( ixi2)2=0.0141l23=l32=ixi2xi3-1n(ixi2)(ix i3)=0l33=ix2i3-1n(ixi3)2=0.0627l1y=ixi1y i-1n(ixi1)(iyi)=-0.0047l2y=ixi2yi-1n(ix i2)(iyi)=-0.0037l3y=ixi3yi-1n(ixi3)(iyi )=-0.0328这样,常数项矩阵B和系数矩阵A可求出如下:B=iyil1yl2yl 3y=12.1810-0.0047-0.0037-0.0328;A=n0000l11l 12l130l21l22l230l31l32l33=900000.137200000. 014100000.0627;C=1900L-1而L-1〔5〕=0.13720000. 01410000.0627100010001=1000100017.288600070 .922000015.9490μ0=Y=1.3534;b1b2b3=7.2886000 70.922000015.9490-0.0047-0.0037-0.0328b1=7. 2886×(-0.0047)+0×(-0.0037)+0×(-0.0328)=-0.0 343b2=0×(0.0047)+70.9220×(-0.0037)+0×(-0.03 28)=-0.2624b3=0×(-0.0047)+0×(-0.0037)+15.94 90×(-0.0328)=-0.5231∴回归值Y=μ0+b1(x1-x1)+b2(x 2-x2)+b3(x3-x3)=1.3534+(-0.0343)(x1+0.8410) +(-0.2624)(x2+0.7467)+(-0.5231)(x3-2.0182)=2.1843-0.0343x1-0.2624x2-0. 2624x2-0.5231x3此式再经变换得刀具耐用度的三因素公式为:T=152.9V0.52f0.26a0.03p4结论通过以上试验研究.
BW Bewise Inc.
Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users’ demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting tool、aerospace tool .HSS Cutting tool、Carbide end mills、Carbide cutting tool、NAS Cutting tool、Carbide end mill、Aerospace cutting tool、Фрезеры’Carbide drill、High speed steel、Milling cutter、CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) ’Core drill、Tapered end mills、CVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden Finger’PCD V-Cutter’PCD Wood tools’PCD Cutting tools’PCD Circular Saw Blade’PVDD End Mills’diamond tool ‘Single Crystal Diamond ‘Metric end mills、Miniature end mills、Специальные режущие инструменты ‘Пустотелое сверло ‘Pilot reamer、Fraises’Fresas con mango’ PCD (Polycrystalline diamond) ‘Frese’Electronics cutter、Step drill、Metal cutting saw、Double margin drill、Gun barrel、Angle milling cutter、Carbide burrs、Carbide tipped cutter、Chamfering tool、IC card engraving cutter、Side cutter、NAS tool、DIN tool、Special tool、Metal slitting saws、Shell end mills、Side and face milling cutters、Side chip clearance saws、Long end mills、Stub roughing end mills、Dovetail milling cutters、Carbide slot drills、Carbide torus cutters、Angel carbide end mills、Carbide torus cutters、Carbide ball-nosed slot drills、Mould cutter、Tool manufacturer.
Bewise Inc. www.tool-tool.com
BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт www.tool-tool.com для получения большей информации.
留言列表