The oxidation mechanism of Mg at high temperature and p rotection techniques of present Mg alloy from ignition are briefly reviewed. The principle and technical details of on-line protective atmosphere for Mg alloy are introduced. Continuously quantitative additions of S

C into reactor maintain ed at a given temperature react with clean compressed air to generate protective atmosphere SO 2 and asistant protective atmosphere CO 2 with controllable and adjustable concentration. The results showed that the burning loss rate of liqu id Mg alloy with on-line protection only is 3.8% lower than that wit h SO 2 and FS 6 protection. The on-line protective effects are reliable

avai lable

less expensive for S

C resulting in economic advantages.