结晶轮用Cu-Cr-Zr合金的低周疲劳性能  

Low cycle fatigue properties of Cu-Cr-Zr alloy for crystallization wheel

作　　者：王旭 肖柱[1] 李周[1] WANG Xu;XIAO Zhu;LI Zhou(School of Materials Science and Engineering,Central South University,Changsha 410083,Hunan,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《金属功能材料》2023年第6期10-17,共8页Metallic Functional Materials

基　　金：国家自然科学基金(U2202255)。

摘　　要：研究了轮带式连铸机结晶轮用Cu-Cr-Zr合金的低周疲劳性能及微观组织演变。试验所用Cu-0.65Cr-0.15Zr(质量分数,%)合金在氩气保护氛围下于中频真空铸造炉中进行制备,并依次进行均匀化、热轧、固溶和时效处理,得到最终状态的合金。采用疲劳试验研究不同总应变幅下合金的低周疲劳性能,并结合扫描电子显微镜(SEM)以及电子背散射衍射(EBSD)分析疲劳试验过程中合金的显微组织演变和裂纹扩展规律。结果表明:总应变幅为0.4%,0.6%和0.8%时,Cu-Cr-Zr合金的疲劳寿命分别为5777次,1185次和661次。经过拟合后,Basquin公式和Coffin-Manson公式可以分别描述合金的疲劳寿命与弹性应变幅和塑性应变幅之间的关系。Cu-Cr-Zr合金的疲劳断裂以穿晶断裂的形式,沿着晶粒中某些特定的晶面进行,因此疲劳裂纹在扩展过程中会发生偏折。The low cycle fatigue properties and microstructure evolution of a Cu-Cr-Zr alloy used in the crystallization wheel of rotary wheel caster has been studied.The Cu-0.65Cr-0.15Zr(wt.%)alloy used in the experiment was prepared in a medium frequency vacuum casting furnace under argon atmosphere,followed by homogenization,hot rolling,solid solution and aging treatment in order to obtain the final alloy.The low cycle fatigue properties of the alloy under different total strain amplitudes were studied by fatigue test,and the microstructure evolution and crack propagation of the alloy were analyzed by scanning electron microscopy(SEM)and electron back scattering diffraction(EBSD).The results showed that the fatigue life of the Cu-Cr-Zr alloy were 5777 cycles,1185 cycles and 661 cycles,respectively,for samples with the total strain amplitude of 0.4%,0.6%and 0.8%.Fitted Basquin formula and Coffin-Manson formula can describe the relationship between the fatigue life of the alloy and elastic strain/plastic strain amplitude,respectively.The mechanism of fatigue fracture of Cu-Cr-Zr alloy is transgranular fracture along some specific crystal planes in the grains,so the fatigue cracks kinked during the propagation process.

关 键 词：CU-CR-ZR合金 低周疲劳性能 疲劳寿命 穿晶断裂 

分 类 号：TG146.11[一般工业技术—材料科学与工程]