Effect of Preheating Temperature on Microstructure of Fe Based Alloy Coating by Laser Direct Metal Deposition

Abstract:

A Fe60 alloy coating was deposited on the surface of Q235 steel by semiconductor laser under the different preheating temperature at 25°C, 100°C, 150°C, 200°C, 250°C, 300°C respectively. The structure and hardness of the samples were analyzed by the means of OM、SEM、XRD、micro-hardness tester. The results show that: A Fe60 alloy coating with high Cr and C content was prepared on the steel substrate by using optimized process parameters, the interface bonding was formed between the coating and the substrate, the thickness of the coating without cracks and porosities is about 6-10mm. There are equiaxed and dendrite crystals in the coating and the phase of coating is composed of α-Fe, γ-Fe,{Fe,Ni} solid solution, Fe3C, Cr2B, Cr7C3. Preheating treatment has good eliminating coating cracks role in the laser deposited Fe-based coating with high Cr and C content, the sample preheated at 200°C has the finest crystalline structure, and the thickness is 8mm and the hardness is up to 806HV. Preheating treatment is an effective method to eliminate the cracks in the high thickness Fe60 alloy coating by laser direct deposition.

• Periodical: Key Engineering Materials (Volume 703)
• Pages: 94-99
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.703.94
• Online since: August 2016
• Authors: Rui Rui Shi, Sui Yuan Chen*, Yong Gang Peng, Zhao Zhang
• Keywords: Cracks Elimination, Fe60 Alloy Coating, Laser Direct Metal Deposition, Preheating Treatment

References

[1] Q.T. Li, H.G. Fu, Y.P. Lei. Research development of iron-based wear-resistant coating fabricated by laser cladding technique. Journal of Beijing University of Technology, 39(2013)1552-1560.

[2] M.L. Zhong, W. j. Liu. Leading areas and hot topics on global laser materials processing research. Chinese Journal Lasers, 35(2008)1653-1659.

DOI: 10.3788/cjl20083511.1653

[3] S. Li, Q.W. Hu, X.Y. Zeng. Research development of Fe-based alloy powder for laser cladding. Laser Technology, 28(2004)591-594.

[4] J. Zhang, J.C. Liu, F.Q. Zhang, C. Yan , L.S. Yang, L.B. Ni. Fe-Cr-Si-B coating by laser cladding on nodular cast iron. Transactions of Materials And Heat Treatment. 31(2010)133-137.

[5] R.S. Long, W.J. Liu , F. Xing, H.B. Wang, H.Y. Bian. Effects of substrate preheating on thermal stress during laser metal deposition shaping. Journal of Mechanical Engineering, 45(2009) 241-247.

DOI: 10.3901/jme.2009.10.241

[6] A. Emamian, M. Alimardani, A. Khajepour. Correlation between temperature distribution and in situ formed microstructureof Fe-TiC deposited on carbon steel using laser cladding. Applied Surface Science, 25(2012)9025-9031.

DOI: 10.1016/j.apsusc.2012.05.143

[7] V. Hemmati, k. Oceli, M. Jameker, D. Hosson. Dilution effects in laser cladding of Ni–Cr–B–Si–C hardfacing alloys. Materials Letters, 84(2012)69-72.

DOI: 10.1016/j.matlet.2012.06.054