Degreasing agent: (1) Alkaline degreaser, composed of alkali, chelating agent and surfactant, including composite high-efficiency degreaser, high-temperature strong degreaser and so on.

(2) Emulsion degreaser, which can remove the dirt on the metal surface by the wettability, penetrability, emulsification, and dispersibility of the surfactant; generally one of the anionic, cationic, and nonionic surfactants is used. Or several mixtures and diluted with water to make an emulsion.

(3) Solvent degreasers, which are degreased by impregnation or steam. The main solvents used are halogenated hydrocarbon solvents and fluorinated hydrocarbon solvents.