压痕法对韧性材料和脆性材料断裂韧性的评价

压痕法对韧性材料和脆性材料断裂韧性的评价2013.08.30.WonJeJo内容

介绍压痕法断裂韧性模型-脆性破坏

韧性断裂

验证模型

压痕法对其他测试方法对比结果

低温应用压痕法断裂韧性基本概念R=250m压头[Material:APIX70]加载约束效应2.13.22.33.0三维裂纹尖端

三轴压痕单边缺口压痕2压痕断裂韧性类似的情况3初始裂纹裂纹钝化塑性区（断裂过程区）不稳定扩展裂纹接触前塑性区发展塑性区发展延长能量概念=裂纹扩展所需能量压痕区域等效断裂能分析压痕过程4压痕过程形成一个表面塑性带5形成一个完全伸展的塑性区

(c/a是常数)扩张的塑性区

(c/a增加)caca设想开始形成一个完全伸展的塑性区=最大应变能量的压头≈形成的等效断裂能量h*6c/ahh*脆性材料韧性材料断口形状变形相对很少或没有变形大量塑性变形尺度应力控制裂纹尖端的临界断裂应力

(sf)应变控制裂纹尖端的临界断裂应变

(ef)形成断裂能当应力达到临界应力当应变达到临界应变断裂行为7脆性断裂模型韧性断裂模型脆性断裂模型8依据9临界深度

(h*)εrr临界压力

在临界深度

h*依据塑性区域弹性区域假定开始形成一个完全延伸塑性区域=形成等效的断裂能量10应用压痕理论步骤.1

屈服的外围接触面积→形成一个表面塑性面步骤.2塑性区→形成完全的扩张延伸塑性区cah*11赫兹弹性接触理论接触区域的外压力

(r≥a)当一个径向应力在接触区域边缘（r=a）满足屈服准则通过

Mises’屈服准侧12压头材料扩大控模型

(E-P理论)塑性区应力

(a≤r≤c)变化的核心压力

(r=a)直到完全扩展延伸区域形成byK.E.Puttick(1977)13核心等效断裂能量的准侧步骤

1所需的总压力等效断裂能量

步骤

214对脆性材料的断裂韧性

Pm-h曲线

压痕深度曲线每个卸载深度曲线意味的接触压力

(1)压痕测试(6)压痕断裂韧性

(KJC)(2)测量屈服强度

σys&决定加载力Pmc-σys从载荷-深度曲线分析而来(3)装配

Pm-h曲线-(4)决定

h*-决定

Pmc

在Pm-h曲线(5)临界深度h*

等效断裂能15韧性材料模型16依据17关键压痕深度

(h*)εrr在h*临界应变依据18吸收应变能直到断裂应变=韧性

(拉伸能量)在h*临界应变依据应变应力高碳钢中碳钢低碳钢设想弹性能量释放由于裂纹增长等于裂纹尖端塑性功数量.[PeelandFrosyth,1973]塑性单位面积r:塑性区半径UT:单位面积的塑性功对于小范围屈服,单位面积上的弹性能量释放〓19塑性功[Mechanicalmetallurgy,G.E.Dieter]塑性功

=应力-应变曲线的截取面积sR:真实应力ef:工程断裂应变20力学参数从压痕参数中估计塑性区域尺寸断裂应变测量参数弹性性能vs.塑性性能函数均匀应变

屈服强度

抗拉强度

弹性模量

松泊比,n=0.3断裂韧性rcef从测量中计算出来的21塑性区域尺寸,rcP塑性应变弹性约束塑性区域塑性应变与弹性约束之间的平衡主导弹性约束主导塑性应变SmallPZSLargePZSResilience断裂应变,ef真实均匀应变与工程断裂应变实验关系,22塑性区尺寸断裂应变测量参数断裂韧性对韧性材料断裂韧性23

验证模型

压痕法对其他测试方法对比结果

低温应用测试材料的列表材料拉伸测试结果KJC从J方法测试结果EYSUTSnefUniformstrainSpecimenthicknessJCKJC(Avg.)Stdev.MPammkJ/m2MPa√m

1碳钢(结构钢)SCM4207000723.349994.4880.1300.1680.066843.68106.160.342SK3207000315.100706.5270.2630.3560.180834.7688.8610.823SKS3207000434.900755.5020.2180.3140.160860.60118.175.784SKH51207000294.850784.3720.2590.1710.117814.5759.754.365SKD11207000342.800807.6870.2550.1180.099840.5298.376.836SUJ2207000404.300821.6590.2400.3330.161854.38113.8713.037S45C207000338.473727.8050.2690.2730.14715144.61181.325.078SCM21207000288.752579.3490.2230.2980.14215339.98281.3712.039SS400207000259.399497.0340.2380.3800.18220423.05310.210.0510SKD61207000377.415765.8150.2350.3100.14220571.61360.583.0211低温度.管道A106207000304.523583.1540.2170.3030.15813.5304.56263.0313.5812Cr-Mo(锅炉管道)A387G22207000519.350689.0200.1420.2490.08516518.58343.1418.1213API(石油管道)X65207000466.913650.8750.1690.3500.14914372.91291.187.9914X100207000598.560918.0720.1410.2510.08919548.24352.8019.0715X120207000745.8631022.9690.1300.2000.05416687.95395.529.2516不锈钢SUS403207000335.277671.5270.2120.3600.15413332.40274.9810.9217SUS420J2207000398.468797.6890.2070.2900.1248103.87155.2910.5818SUS440207000329.900820.7670.2560.2150.118826.3385.020.1219SUS304207000285.6851138.3780.3590.7740.49320537.13349.2717.0520SUS304L207000258.8161164.7280.4020.6540.42720666.29389.2111.0421SUS347207000244.863999.4890.3690.6440.41623591.39366.746.4322SUS321207000252.4021039.9660.3730.7240.47122499.02336.912.6723铝合金Al202470000459.100669.3990.1520.1650.128848.2064.077.5324Al707570000517.700621.8130.0800.1360.050817.2436.969.1025铜合金C62400120000433.206842.9450.259-0.06694.8325.610.3526InCu120000160.025480.8550.3280.4830.37117187.25156.8515.1527镍合金Alloy20207000348.337762.1780.2350.3790.20717453.21321.08-

28钛合金Ti-6Al-4V110000937.1281099.8150.080-0.086990.16113.6211.4329Ti-6Al-6V-2Sn1100001009.2301172.5600.076-0.105939.0072.243.1230Ti-5Al-2.5Sn110000885.5691038.0130.066-0.096961.5686.635.7331Ti-10Al-2Fe-3Al1100001163.3181257.3320.096-0.027994.0796.5917.33传统拉伸试验与断裂韧性测试试结果25测试条件26压头压头半径控制方法碳化钨球形压头250um最大深度控制设备AIS系统最大压痕深度150um零指数0.06kgf表面粗糙度#2000+20%-20%KJC

Results压痕法测试KJC(MPa√m)J积分测试KJC(MPa√m)27脆性材料模型韧性材料模型KJC

结果脆性材料韧性材料DuctileMaterialJ方法KJC压痕法KJCKJC(Avg.)Stdev.KJC(Avg.)Stdev.MPa√mMPa√m碳钢(结构钢)SCM21281.3712.03256.504.73SS400310.210.05235.4515.18SKD61360.583.02316.4710.96低温度管道A106263.0313.58242.6011.01Cr-Mo(锅炉管)A387G22343.1418.12273.6311.18API(石油管道)X65291.187.99273.336.03X100352.8019.07330.7513.57X120395.529.25448.105.54不锈钢SUS403274.9810.92251.263.86SUS304349.2717.05373.3821.34SUS304L389.2111.04398.4733.71SUS347366.746.43326.2811.94SUS321336.912.67324.2215.87钛合金Alloy20321.08-292.885.53脆性材料J方法KJC压痕法KJCKJC(Avg.)Stdev.KJC(Avg.)Stdev.MPa√mMPa√m碳钢(结构钢)SCM4106.160.3490.876.62SK388.8610.8289.963.49SKS3118.175.78110.683.10SKH5159.754.3690.1310.99SKD1198.376.8389.827.96SUJ2113.8713.03103.1914.21S45C181.325.07165.809.49不锈钢SUS420J2155.2910.58156.817.94SUS44085.020.1294.779.75铝合金Al202464.077.5352.064.56Al707536.969.1043.873.30铜合金C6240025.610.3516.82-InCu156.8515.15160.376.06钛合金Ti-6Al-4V113.6211.43108.3315.47Ti-6Al-6V-2Sn72.243.1250.076.96Ti-5Al-2.5Sn86.635.7392.2110.47Ti-10Al-2Fe-3Al96.5917.3375.1915.1428低温系统

评价断裂韧性与气温的变化

低温在断裂韧性的测量使用

ASTME1921在零下温度下分析[应用]

真空腔尺寸(WxDxH)410x300x160(mm)冷却元件液氮

环境测试真空、隔离

最低温度.-160oC冷却速度~40oC/min(~40oF/min)[规格]29恒温槽控制器AIS系统真空腔V型断口样品

压痕法与V型断口试验结果关系-材料:2.25Cr1MoVsteel(焊接)-试验温度：常温

和

-29oC低温测试应用30压痕法冲击试验压痕法冲击试验室温低温下的应用

–

主要曲线○:KJC

压痕法▲:KJCJ方法

样品信息与测试条件化学成分(wt.%)CSiMnPSNi0.210.241.360.0070.0020.92CrMoAlCuV0.210.490.0220.030.005

化学成分材料SA508-3,ID:GS880样品V型缺口试样用途核反应堆压力容器温度范围(大约零下10℃）-110~-20℃断裂韧性测试依据ASTME192031[参考:Bong-SangLee,Min-ChulKim,Maan-WonKim,Ji-HyunYoon,Jun-HwaHong,“理论曲线技术来