Effects of contact pressure, interface temperature, and surface roughness on thermal contact conductance between stainless steel surfaces under atmosphere condition

An experiment was performed to investigate the effects of interface temperature, specimen surface roughness, and contact pressure on thermal contact conductance (TCC). Specimens were prepared using SUS 304 stainless steel, the interface temperature was in the region of 360-640 °C, the contact pressure was between 2.39 and 15.17 MPa, and the surface roughness ranged from 0.25 μm to 2.00 μm. All experiments were conducted in ambient atmosphere. Results indicated that TCC presents a power law relationship with contact pressure and interface temperature. While the contact pressure exponent varied between 0.20 and 0.46 at different surface roughness, the interface temperature exponent showed a much wider range of 0.45-2.36. TCC increased more rapidly with temperature in specimens with higher surface roughness than in those with lower surface roughness. The correlation equations between thermal contact conductance, contact pressure, and interface temperature revealed a relative error of 20%.