| 摘要 |
PURPOSE:To obtain the heat receiving surface of a high corrosion-resisting heat collector with an excellent selective absorptive surface by forming an oxide layer of specific film thickness to the mirror surface of high chromium stainless steel when manufacturing the selective absorptive heat receiving surface of the heat collector utilizing solar heat. CONSTITUTION:High chromium stainless steel with the mirror surface of 20- 35% weight content chromium is immersed in a chromic acid-solfuric acid solution of a mol ratio of chromic acid to sulfuric acid of 0.003-0.24, and the oxide layer of film thickness of 500Angstrom -2,000Angstrom is formed to the surface of the stainless steel. A selective absorptive surface of a spectral reflecting curve shown in a curve 1 is obtained by the presence of such an oxide layer. Said coating indicates high energy absorptance in a wavelength band of 0.3-2.5mum, and indicates energy emissivity in a wavelength band of 3-50mum. |
