What are the materials of высокотемпературная трубчатая печь tubes?

The materials of the high-temperature tube furnace are: 314 heat-resistant steel, quartz glass, corundum ceramics, high-purity alumina ceramic tubes and other materials. Generally speaking, 800-1200 degree tube furnace uses 314 stainless steel tube or quartz glass tube, and 1400 degree tube furnace uses 99 corundum ceramic tube.