Ac: Absorption coefficient, m⁻¹,

Ac₁: Heating temperature at point A₁, ˚C,

Ac₃: Heating temperature at point A₃, ˚C,

C_p: Specific heat, J·kg⁻¹·K⁻¹,

d: length of the line, m,

f_r: frequency, Hz,

h: Thermal transfer coef., W·m⁻²·K⁻¹ ,

K: Thermal conductivity air, W·m⁻¹·K⁻¹ ,

L: piece length, m,

l: piece width, m,

L_Z: piece thickness, m,

P: Laser power, W.

R_c: reflection coefficient of the material,

T: Temperature of the material, ˚C,

T_in: Initial material temperature, ˚C,

T_amb: Ambient air temperature, ˚C,

SS: Scanning speed, mm/s,

λ: Thermal conductivity steel, W·m⁻¹·K⁻¹,

σ: Stefan-Boltzmann constant, W·m⁻²·K⁻⁴,

x₀: Radius of the laser spot, m,

y₀: Radius of the laser spot, m,

γ: Thermal diffusivity, m²·s⁻¹,

ε: Emissivity of material surface,

ρ: Density, kg·m⁻³.