摘要
采用3kW半导体宽带激光器在28CrMoNiV钢基板上进行了激光熔覆试验,并结合热影响区(HAZ)温度场模拟优化了再制造工艺。通过光学显微镜、扫描电镜和X射线衍射仪对HAZ和基体的组织进行了分析。最后通过拉伸试验对修复后的熔覆HAZ进行了性能测试。结果表明,单层熔覆HAZ主要产生了马氏体相变,并在HAZ顶部发现了马氏体和铁素体的不良组织。模拟结果表明,该不良组织可以通过三层以上的多层熔覆方法消除。拉伸性能测试结果表明,三层熔覆HAZ的平均抗拉强度达到927.35 MPa,高于基体或单层熔覆HAZ;断后伸长率达到10.23%,较单层熔覆HAZ有所提高,更接近基体性能。
A laser cladding test on a 28CrMoNiV substrate by a 3 kW broadband semiconductor laser is conducted, and the refabrication process is optimized with the aid of simulation of the temperature fields in the areas of heat- affected zones （HAZ）. By means of optical microscope, scanning electron microscope, and X-ray diffraction, the microstructures in the HAZ and substrate zone are studied. The tensile test is conducted to investigate the tensile performance of the repaired laser cladding HAZ. The results show that, in the HAZ of the single-layer cladding sample, there exists a martensite phase transformation and an undesirable microstrueture composed of martensite and 3-ferrite distributes at the top of the HAZ. The simulation results indicate that this undesirable microstructure can be eliminated if the over-three-layer cladding is adopted. The tensile testing results show that the HAZ with three-layer cladding has the average tensile strength up to 927.35 MPa, which is higher than those of the substrate or the HAZ with single-layer cladding. The average fractural elongation of the HAZ with three-layer cladding is 10. 23 %, which is a little higher than that of the single-cladding and much closer to that of the substrate.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2016年第8期147-152,共6页
Chinese Journal of Lasers
基金
浙江省公益技术研究工业项目(2014C31122)
