摘要
采用电阻炉对轧制后的5A02合金薄壁管材进行了均匀化退火,利用光学显微镜、硬度计和万能试验机分析了退火制度对5A02合金薄壁管材组织与性能的影响。研究结果表明:当退火温度较低时,保温60min后的合金组织中仍然存在一定量的纤维状组织,当退火温度升高到410℃时,保温30min后管材中的纤维状组织已完全消失,再结晶组织较细小;随着退火温度的升高和保温时间的延长,退火后管材的强度、硬度逐渐降低,伸长率逐渐升高,但保温时间大于30min的性能变化不大;退火温度较低时,试样断口中韧性断裂特征比较明显,但是仍存在少量剪切变形的特征,随着退火温度的升高,合金断口呈出现大量韧性断裂的韧窝组织,没有剪切变形的特征;最终确定了均匀化退火制度为410～430℃,保温时间为30～60min,抗拉强度和伸长率都满足了用户指标的要求。
The cold-rolled thin-wall pipe of 5A02 alloy was homogenizing annealed using a resistance furnace.Optical microscope,hardness testing machine and universal testing machine were used to investigate the effect of homogenizing annealing on the microstructure and properties of 5A02 alloy pipe.It is found that there still exists a certain amount of fibrous structure in 5A02 alloy which annealed at lower temperatures for 60 min.However,with the annealing temperature increasing to 410 ℃ and holding for 30 min,the microstructure is composed of fine recrystallized grains with all the fibrous structure has completely disappeared.The strength and hardness of the annealed 5A02 alloy pipe decrease gradually with the increasing annealing temperature and holding time,while the elongation is gradually increased.It is also found that there is little change in the properties of 5A02 alloy pipe which annealed more than 30 min.At lower homogenizing annealing temperature,the toughness fracture of the alloy is the main features of the fracture surface,in which there still exists a small amount of shear deformation feature.However,the alloy displays a large mount of toughness fractures and nearly no shear deformation features with the increasing annealing temperature.Finally,the homogenizing annealing temperature is determined to be at 410-430 ℃ for 30-60 min,after which the mechanical properties are satisfied with the application requirements.
出处
《锻压技术》
CAS
CSCD
北大核心
2011年第6期103-107,共5页
Forging & Stamping Technology
