摘要
介绍了超低温奥氏体球墨铸铁的低温示波冲击试验,探讨了冲击裂纹的萌生与亚稳扩展特征。通过对示波冲击断裂过程中的动态载荷、吸收能量以及特征位移进行分析发现,随着温度的降低,超低温奥氏体球墨铸铁有着更好的抵抗冲击裂纹萌生的能力,但冲击裂纹萌生后会迅速地延伸并开始亚稳扩展;而冲击裂纹的亚稳扩展过程在冲击值达到最大值的温度(-80℃)前后分别被材料承受载荷的上升和冲击裂纹亚稳扩展区域的减少所影响。通过对冲击断口观察发现,随着温度的下降,冲击断口在裂纹萌生区域的塑性变形持续上升,而在裂纹亚稳扩展区域则呈现先增大后减小的趋势。
The low temperature oscillography impact test of the austenite nodular iron was introduced. The crack producing and its metasble expansion characteristics were discussed. By analyzing the dynamic load,energy absorbing and characteristics displacement in the oseillography impact fracturing process,it was discovered that by the temperature dropping, the ultra-low temperature austenite nodular iron would have more better ability to resist the impact crack producing, however the impact crack would rapidly extend and begin metastable expansion;but the impact crack metastable expansion process would influenced by the load increasing and metastable displacement reducing before and after reaching the temperature（-80 ~C ）when the impact value reaching its maximum. It was discovered by observing the impact fracture that with temperature dropping,the plastic deformation in the crack producing area of the impact fracture continuously increased, however the metastable expansion area showed the trend of increasing at beginning and then decreasing.
出处
《现代铸铁》
CAS
2017年第1期24-27,共4页
Modern Cast Iron
基金
国家自然基金资助项目(51274142)
辽宁省自然科学基金资助项目(2014028015)
沈阳市科学与技术项目资助(F15-199-1-15)
关键词
球墨铸铁
超低温
示波冲击
裂纹萌生
亚稳扩展
nodular iron
ultra-low temperature
oseillography impact
crack producing
metastable expansion
