The demulsifying cleaning of metallic surfaces which may be contaminated with oil(s) with at least one further nonpolar organic compound, with fat(s), with soap(s), with particulate dirt or with at least one anionic organic compound using an aqueous, alkaline, surfactant-containing bath solutions.

The demulsifying cleaning of metallic surfaces which may be contaminated with oil(s) with at least one further nonpolar organic compound, with fat(s), with soap(s), with particulate dirt or with at least one anionic organic compound using an aqueous, alkaline, surfactant-containing bath solutions.

A cleaner composition includes: a saturated aliphatic hydrocarbon (A); an anionic surfactant (B); a nonionic surfactant (C); and water (D). The cleaner composition contains the saturated aliphatic hydrocarbon (A) in a proportion of 60.0% by mass to 85.0% by mass, the anionic surfactant (B) in a proportion of 8.0% by mass to 15.0% by mass, the nonionic surfactant (C) in a proportion of 2.0% by mass to 5.0% by mass, and the water (D) in a proportion of 1.0% by mass to 20.0% by mass, forms a W/O microemulsion or a solubilized W/O emulsion, and has a volume resistivity of 1×10.sup.9 Ω.Math.cm or less.

A cleaner composition includes: a saturated aliphatic hydrocarbon (A); an anionic surfactant (B); a nonionic surfactant (C); and water (D). The cleaner composition contains the saturated aliphatic hydrocarbon (A) in a proportion of 60.0% by mass to 85.0% by mass, the anionic surfactant (B) in a proportion of 8.0% by mass to 15.0% by mass, the nonionic surfactant (C) in a proportion of 2.0% by mass to 5.0% by mass, and the water (D) in a proportion of 1.0% by mass to 20.0% by mass, forms a W/O microemulsion or a solubilized W/O emulsion, and has a volume resistivity of 1×10.sup.9 Ω.Math.cm or less.

A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.

A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.

A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.

A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.

Process for cleaning soiled metal surfaces characterized in such cleaning is carried out using a composition that comprises at least one alkoxylated polyethylenimine (B) with a polydispersity Q=M.sub.w/M.sub.n of at least 3.5 and an average molecular weight M.sub.w in the range of from 2,500 to 1,500,000 g/mol.

Process for cleaning soiled metal surfaces characterized in such cleaning is carried out using a composition that comprises at least one alkoxylated polyethylenimine (B) with a polydispersity Q=M.sub.w/M.sub.n of at least 3.5 and an average molecular weight M.sub.w in the range of from 2,500 to 1,500,000 g/mol.