87.13 Corrosion and protection of metals 1. General introduction: classification Surroundings 额 Surroundings metal (1)Materials metal Local corrosion. (2)Environment 1)uniformity of ()Reaction, metal (4)Uniformity 2)Surface film (5)Othe 3 ) Solutimetal Surroundings (1) Materials: (2) Environment: (3) Reaction; (4) Uniformity; (5) Other 1. General introduction: classification metal film Surroundings Local corrosion: 1) uniformity of metal 2) Surface film 3) Solution §7.13 Corrosion and protection of metals