Laser surface hardening of AISI 420 steel: Parametric evaluation, statistical modeling and optimization

Mahmoud Moradi, Safian Sharif, Saied Jamshidi Nasab, Mojtaba Karami Moghadam

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)
16 Downloads (Pure)


In this study, the AISI 420 was laser surface transformation hardened (LSTH) utilizing a high power diode laser (HPDL). The experimental tests were performed based on design of experiment method. Laser power, laser scanning speed, and focal plane position (FPP) of laser beam were considered as input parameters and their influences on geometry of the hardened area (depth and width), the maximum micro-hardness and the hardness deviation from the base metal were investigated. The laser hardened samples were structurally analyzed by metallurgical investigation and mechanically evaluated by micro-hardness testing; Microstructural studies on laser-treated surfaces were conducted by scanning electron microscopy (FE-SEM) and optical microscope. The micro-hardness of the width and depth of the hardened layer was measured. Macro-image testing has been done to measure the hardened area geometric dimensions accurately. After the aforementioned tests, the interpretation of how the various parameters of the laser are affected by the quantum exit of the components is discussed. Result revealed that when the laser power raises and laser speed fall off, dimension of hardness area were increased. When FPP decreased, hardened depth was decreased and width was raised. Statistical analysis of the results was performed using the Design Expert software to explore the penetration of mechanism parameters on the behavior of responses, to obtain regression equations and to predict the results. Optimization of the LSTH process to achieve an optimal hardness and also optimal settings of parameters were the other goals of this exploration.
Original languageEnglish
Article number165666
Early online date24 Sept 2020
Publication statusPublished - 1 Dec 2020
Externally publishedYes

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  • AISI 420 stainless steel
  • Design of experiments
  • High power diode laser
  • Laser surface transformation hardening
  • Optimization

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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