Multilayer plated fuel line parts for automobile

• US 20050236060A1
• Filed: 07/18/2003
• Published: 10/27/2005
• Est. Priority Date: 07/24/2002
• Status: Abandoned Application

• Current Assignee: Sanoh Kogyo Kabushiki Kaisha
• Original Assignee: Sanoh Kogyo Kabushiki Kaisha
• Inventors: Matsubara, Norifumi
• Application Number:
  US10/519,602
• Publication Number:
  US 20050236060A1
• Time in Patent Office: Days
• US Class Current: 138/143
• CPC Class Codes: C23C 2222/10 Use of solutions containing trivalent chromium but free of hexavalent chromium
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/345 with at least one oxide layer
• CPC Class Codes: C23C 28/3455 with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
• CPC Class Codes: C25D 5/12 at least one layer being of nickel or chromium
• CPC Class Codes: C25D 5/48 After-treatment of electroplated surfaces
• CPC Class Codes: F02M 61/166 Selection of particular materials
• CPC Class Codes: F02M 69/465 of fuel rails

Abstract

A trivalent chromate coating having improved surface smoothness is used as an alternative to a hexavalent chromate coating serving as a protective coating. A piping member of a steel for an automotive fuel line is coated with a multilayer coating consisting of a plated Zn—Ni alloy film as a bottom layer, a plated Zn film as an intermediate layer overlying the plated Zn—Ni alloy layer, and a trivalent chromate layer as a top layer overlying the plated Zn film.

Claims

1. A piping member for an automotive fuel line, coated with a multilayer coating including a chromate coating as a top layer;

characterized in that multilayer coating comprises a plated Zn—

Ni alloy film as a bottom layer, a plated Zn film as an intermediate layer overlying the plated Zn—

Ni alloy layer, and a trivalent chromate layer as a top layer overlying the plated Zn film.

2. The piping member for an automotive fuel line according to claim 1 characterized in that the multilayer coating further comprises a plated Ni film underlying the plated Zn—

Ni alloy film.

3. The piping member for an automotive fuel line according to claim 1 is a fuel delivery pipe provided with cups in which injectors are inserted by press fitting.

4. The piping member for an automotive fuel line according to claim 1, wherein the plated Zn—

Ni alloy film ha a thickness between t and 10 μ

m, the plated Zn film has a thickness between 5 and 10 Mm, and the trivalent chromate coating has a thickness between 0.1 and 1.0 μ

m.