Chrome-plated part and manufacturing method of the same

A method of manufacturing a chrome-plated part, comprising:

• forming a bright nickel plating layer over a substrate;
• forming a noble potential nickel plating layer on the bright nickel plating layer, wherein an electric potential difference between the bright nickel plating layer and the noble potential nickel plating layer is within a range from 78 mV to 150 mV, and the electric potential of the bright nickel plating layer is a base potential with respect to the noble potential nickel plating layer;
• and
• forming a trivalent chrome plating layer on the noble potential nickel plating layer, the trivalent chrome plating layer containing 0.5 at % or more of iron, and having at least any one of a microporous structure or a microcrack structure,
• wherein the trivalent chrome plating layer has a microporous density of 180,000/cm2 or more,
• wherein forming the bright nickel plating layer comprises using a first brightening agent and a second brightening agent,
• wherein the first brightening agent comprises 1,5-sodium naphthalene disulfonate, 1,3,6-sodium naphthalene trisulfonate, saccharin, or paratoluene sulfonamide, and
• wherein the second brightening agent comprises formaldehyde, 1,4-butynediol, propargyl alcohol, ethylene cyanohydrin, coumarin, thiourea, or sodium allylsulfonate.

A chrome-plated part, comprising:

• a substrate;
• a bright nickel plating layer formed over the substrate;
• a noble potential nickel plating layer formed on the bright nickel plating layer, wherein an electric potential difference between the bright nickel plating layer and the noble potential nickel plating layer is within a range from 78 mV to 150 mV, and the electric potential of the bright nickel plating layer is a base potential with respect to the noble potential nickel plating layer;
• and
• a trivalent chrome plating layer formed on the noble potential nickel plating layer, containing 0.5 at % or more of iron, and having at least any one of a microporous structure or a microcrack structure,
• wherein the trivalent chrome plating layer has a microporous density of 180,000/cm2 or more,
• wherein the bright nickel plating layer comprises a first brightening agent and a second brightening agent,
• wherein the first brightening agent comprises 1,5-sodium naphthalene disulfonate, 1,3,6-sodium naphthalene trisulfonate, saccharin, or paratoluene sulfonamide, and
• wherein the second brightening agent comprises formaldehyde, 1,4-butynediol, propargyl alcohol, ethylene cyanohydrin, coumarin, thiourea, or sodium allylsulfonate.