摘要
利用激光熔化沉积技术制备AerMet100超高强度钢厚板试样,利用OM、SEM和EDS研究了激光熔化沉积态组织,通过在885~1150℃范围内的高温固溶热处理研究了激光熔化沉积AerMet100钢的高温组织稳定性。结果表明,激光熔化沉积态AerMet100钢具有细小均匀、沿沉积方向定向生长的快速凝固胞状树枝晶组织,合金元素在胞晶尺寸范围内存在一定的凝固偏析,激光熔化沉积各层之间存在层间热影响区,而且AerMet100钢激光熔化沉积快速凝固胞状树枝晶组织具有异常优异的高温组织稳定性,其快速凝固胞状树枝晶特征可以保持到1100℃,＂原位＂快速凝固胞状树枝晶极低的界面能及其很弱的凝固偏析是该组织具有异常优异的高温组织稳定性的主要原因。
The thick plate sample of ultrahigh strength steel AerMet100 was fabricated by the laser melting deposition（LMD）.Microstructure of the laser deposited steel was studied by optical microscopy（OM）,scanning electron microscopy（SEM） and energy dispersive X-ray spectroscopy（EDS）,and high temperature structural stability of which was researched by high temperature solution treatment during 885-1150 ℃.The results indicate that the rapidly solidified cellular-dendrite structure of the laser deposited steel is fine and homogeneous,and grows directionally along the deposition orientation.Solidification segregation of alloy elements exists between the dendrites and the interdendritic regions,and interlayer heat-affected zone exists between adjacent layers of the laser deposited steel.The rapidly solidified structure has excellent high temperature stability,which was mainly attributed to the low interfacial energy of the dendrite and the slight solidification segregation of alloy element between the dendrites and the interdenrtic regions.
出处
《金属热处理》
CAS
CSCD
北大核心
2011年第3期60-63,共4页
Heat Treatment of Metals
基金
国家杰出青年科学基金(50625413)
关键词
激光熔化沉积
超高强度钢
凝固组织
高温组织稳定性
laser melting deposition
ultrahigh strength steel
solidified structure
high temperature structural stability
