欧美特大特白屁股ass - 欧美精品福利一区二区三区 - 亚洲国产综合精品2022 - 偷窥中国老太XXXX

Vacuum Furnace Molybdenum Heat Shield and hearing Belts

Refractory metals have a high melting point, low vapor pressure, low coefficient of thermal expansion, excellent high temperature strength and creep resistance. Through alloying, their processing properties and high temperature performances are further improved, and the service life of products is extended. Therefore, tungsten, molybdenum, tantalum and niobium metals are widely used in all kinds of high temperature furnaces as structural materials, heating body and insulation layer.