A two-layer wall is made of two metal plates, with surface roughness of about 25 mm, pressed together at an average pressure of 10 MPa. The first layer is a stainless steel plate with a thickness of 5 mm and a thermal conductivity of 14 W/m∙K. The second layer is an aluminum plate with a thickness of 15 mm and a thermal conductivity of 237 W/m∙K. On the stainless steel side of the wall, the surface is subjected to a heat flux of 800 W/m². On the aluminum side of the wall, the surface experiences convection heat transfer at an ambient temperature of 20°C, where the convection coefficient is 12 W/m²∙K. Determine the surface temperature of the stainless steel plate.