Estimation of Surface Absorptivity and Surface Temperature in Laser Surface Hardening Process

1996 ◽  
Vol 35 (Part 1, No. 6A) ◽  
pp. 3658-3664 ◽  
Author(s):  
Yann-Shouh Sun ◽  
Cheng-I Weng ◽  
Tei-Chen Chen ◽  
Wang-Long Li
Keyword(s):  
Surface Temperature ◽  
Surface Hardening ◽  
Laser Surface ◽  
Hardening Process ◽  
Laser Surface Hardening

scholarly journals Feasibility Studies on Underwater Laser Surface Hardening Process

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Biao Jin ◽  
Min Li ◽  
TaeWoo Hwang ◽  
YoungHoon Moon
Keyword(s):  
Tool Steel ◽  
Surface Hardening ◽  
Feasibility Studies ◽  
Laser Surface ◽  
Hardening Process ◽  
Average Hardness ◽  
Laser Surface Hardening ◽  
Underwater Laser ◽  
Nonferrous Alloys ◽  
Melting Experiment

Laser surface hardening process is a very promising hardening method for ferrous and nonferrous alloys where transformations occur during cooling after laser melting in the solid state. This study experimentally characterizes laser surface hardening of tool steel in both water and air. For the underwater operation, laser surface scanning is performed over the tool steel surface which is immersed in water. The laser surface hardening tests are performed with a maximum 200 W fiber laser with a Gaussian distribution of energy in the beam. For the surface hardening, single-track melting experiment which sequentially scans elongated path of single line has been performed. As the hardened depth depends on the thermal conductivity of the material, the surface temperature and the penetration depth may be varied by underwater laser processing. The feasibility of underwater laser surface hardening process is discussed on the basis of average hardness level and hardened bead shape.

scholarly journals Experimental investigation on a novel approach for laser surface hardening modelling

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
L. Orazi ◽  
A. Rota ◽  
B. Reggiani
Keyword(s):  
Surface Hardening ◽  
Carbon Diffusion ◽  
Industrial Applications ◽  
Laser Surface ◽  
Simplified Approach ◽  
Laser Surface Hardening ◽  
Novel Approach ◽  
Laser Treatments ◽  
High Flexibility ◽  
Short Time

AbstractLaser surface hardening is rapidly growing in industrial applications due to its high flexibility, accuracy, cleanness and energy efficiency. However, the experimental process optimization can be a tricky task due to the number of involved parameters, thus suggesting for alternative approaches such as reliable numerical simulations. Conventional laser hardening models compute the achieved hardness on the basis of microstructure predictions due to carbon diffusion during the process heat thermal cycle. Nevertheless, this approach is very time consuming and not allows to simulate real complex products during laser treatments. To overcome this limitation, a novel simplified approach for laser surface hardening modelling is presented and discussed. The basic assumption consists in neglecting the austenite homogenization due to the short time and the insufficient carbon diffusion during the heating phase of the process. In the present work, this assumption is experimentally verified through nano-hardness measurements on C45 carbon steel samples both laser and oven treated by means of atomic force microscopy (AFM) technique.

scholarly journals Laser surface hardening of SS316L

2021 ◽  
Vol 1070 (1) ◽  
pp. 012107
Author(s):  
Ganesh Dongre ◽  
Avadhoot Rajurkar ◽  
Ramesh Gondil ◽  
Nandan Jaju
Keyword(s):  
Surface Hardening ◽  
Laser Surface ◽  
Laser Surface Hardening

Laser Surface Hardening of Gray Cast Iron Used for Piston Ring

2002 ◽  
Vol 11 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Jong-Hyun Hwang ◽  
Yun-Sig Lee ◽  
Dae-Young Kim ◽  
Joong-Geun Youn
Keyword(s):  
Cast Iron ◽  
Surface Hardening ◽  
Piston Ring ◽  
Gray Cast Iron ◽  
Laser Surface ◽  
Gray Cast ◽  
Laser Surface Hardening

Water-Jet Assisted Laser Surface Hardening of Medium Carbon Steel Using Fiber Laser

2018 ◽  
Author(s):  
Sagar Sarkar ◽  
Ashish Kumar Nath
Keyword(s):  
Surface Hardening ◽  
High Hardness ◽  
Medium Carbon Steel ◽  
Water Jet ◽  
Laser Surface ◽  
Peak Hardness ◽  
Bottom Surface ◽  
Thin Sheets ◽  
Laser Surface Hardening ◽  
Conventional Laser

Laser surface hardening of most of the industrial components require depth of surface modification in the range of 100–150 micron. Conventional laser surface hardening uses laser as a heat source to modify a particular area of the surface without melting in an inert gas environment. However, the hardened profile in this case shows peak hardness value at a certain depth from the top surface. Also, hardening the top surface to get relatively much higher hardness near the top surface in case of thin sheets becomes difficult due to accumulation of heat below the surface of the specimen which in turn lowers the cooling rate. Hence, self-quenching becomes inadequate. In the present study, an in-house fabricated laser processing head with coaxial water nozzle has been used to flow a laminar water-jet during the laser surface hardening process to induce forced convection at the top surface. Thus, heat gets carried away by the water-jet from the top surface and by the water from the bottom surface as well. Results show that with judicious selection of process parameters, it is possible to get higher hardness (800 HV) to that of conventional laser surface hardening (500 HV) at the top surface using this process. Present process can be used for those cases where high hardness values are required near the top surface specially for thin sheets and thermally sensitive materials.

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