加载方式对28CrMo钢疲劳裂纹扩展的影响  

Effect of loading modes on fatigue crack growth behavior of 28CrMo steel

作　　者：陈孝文[1] 张德芬[1] 石霜霜[1] 王立君[2] 吕东莉[1] 施太和[3] 

机构地区：[1]西南石油大学材料科学与工程学院,四川成都610500 [2]天津大学材料科学与工程学院,天津300072 [3]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500

出　　处：《材料热处理学报》2013年第11期109-113,共5页Transactions of Materials and Heat Treatment

基　　金：天津市自然科学基金(11JCYBJC06000)

摘　　要：利用疲劳试验机研究了28CrMo钢在三角波、方波和正弦波3种加载方式下三点弯曲疲劳实验过程中疲劳裂纹扩展速度与自发射磁信号的相关性,用扫描电镜对疲劳断口特征进行了研究。结果表明:加载方式不同,疲劳裂纹扩展速度不同,其中三角波加载方式下裂纹扩展速度最快,自发射磁信号最大,正弦波加载方式下裂纹扩展速度最慢,其自发射磁信号最小,方波加载方式则介于两者之间。基于磁荷概念和Ansys模拟结果分析了不同加载方式下疲劳裂纹扩展过程中自发射磁信号的变化规律。断口扫描分析结果表明3种加载方式下的疲劳断口均为类解理断裂。The relationship between fatigue crack growth rate and self-emitting magnetic signal was studied in the three-point bending fatigue experiment for 28CrMo steel using different loading waveform on a electro-hydraulic servo fatigue testing machine. The characteristics of fatigue fracture was studied by SEM. The results show that the growth rate of fatigue cracks depends on the loading modes, of which the triangular wave loading brings the fastest growth rate and the most intense self-emitting magnetic signal, the sinusoidal wave loading brings the slowest rate and the weakest signal, while the square wave loading gives the intermediate values. A theoretical study, based on the concept of magnetic charge and the results of Ansys simulation, was carried out to analyze the variation of self-emitting magnetic signals of 28CrMo steel during fatigue crack growth under different loading modes. The fracture observation by SEM reveals that cleavage-like fatigue fracture occurs under all the three loading modes.

关 键 词：加载方式 金属磁记忆 疲劳裂纹 ANSYS模拟 磁荷 

分 类 号：TG142.4[一般工业技术—材料科学与工程]