Two dimensional finite element thermal model of laser surface glazing for H13 tool steel

Abstract

A two dimensional (2D) transient thermal model with line-heat-source was developed by Finite Element Method (FEM) for laser surface glazing of H13 tool steel using commercial software-ANSYS 15. The geometry of the model was taken as a transverse circular cross-section of cylindrical specimen. Two different power levels (300W, 200W) were used with 0.2mm width of laser beam and 0.15ms exposure time. Temperature distribution, heating and cooling rates, and the dimensions of modified surface were analysed. The maximum temperatures achieved were 2532K (2259°C) and 1592K (1319°C) for laser power 300W and 200W respectively. The maximum cooling rates were 4.2×10 7 K/s for 300W and 2×10 7 K/s for 200W. Depths of modified zone increased with increasing laser power. From this analysis, it can be predicted that for 0.2mm beam width and 0.15ms time exposer melting temperature of H13 tool steel is achieved within 200-300W power range of laser beam in laser surface glazing.

3D thermal model of laser surface glazing for H13 tool steel

“…3b. Although total depth of HAZ were similar for both 2D [13] and 3D cases, the depth of melt pool was larger in 3D case. Around 2.5μm increment of the depth of melt pool for 300W was observed.…”

“…The maximum surface temperature after heating for power 200W was 1668.67K and was 2554.54K for 300W. Comparing with 2D numerical case the maximum surface temperatures achieved from 3D case were 71K higher for 200W and 22K higher for 300W [13]. This was probably due to the increased surface heat flux in the 3D model.…”

“…(a) (b) This thermal cycles graphs can be further used to estimate possible phase fractions by superimposing critical isothermal temperature lines for phase transformation as done in [13,14]. Table 2 showed heating and cooling rates of the surface (curve A) for different power levels.…”

“…Both rates increased with increasing power. Both heating and cooling rates were slightly higher than the 2D model because of higher maximum temperature obtained in 3D case [13]. The temperature distribution calculated form analytical solution [see Eqs.…”

“…In this work, a 3D finite element (FE) model was developed extending from author's previous 2D modelling work of LSG for H13 tool steel [13]. Temperature distribution, depth of modified zone, heating and cooling rates were analysed from the 3D FE model.…”