IP Library Granted Patent US 12668860
Granted Patent B2
US 12668860 · App. 17/603,434 · Granted Jun 30, 2026

Zinc-plated steel sheet for hot stamping, method of manufacturing zinc-plated steel sheet for hot stamping, and hot-stamping formed body

Inventors: Hiroyuki Nakagawa (Tokyo, JP); Hiroki Akutsu (Tokyo, JP)
Assignee: NIPPON STEEL CORPORATION
C22C38/58B21D22/022C21D8/02C21D8/0226C21D8/0236C22C38/002C22C38/005C22C38/02C22C38/06C22C38/42C22C38/44C22C38/46C22C38/48C22C38/54C23C2/02C23C2/0222C23C2/06C23C2/28C23C2/29C23C2/40C22C38/50
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12668860
App. No.
17/603,434
Granted
Jun 30, 2026
Kind
B2
Abstract

A zinc-plated steel sheet for hot stamping includes a steel sheet having a predetermined chemical composition and a zinc plating film disposed on the steel sheet. In the zinc plating film, the plating adhesion amount is 15.0 g/m 2 or more and less than 40.0 g/m 2 , the Fe concentration is 1.5 mass % or more and 8.0 mass % or less, the Al content is 100 mg/m 2 or more and 400 mg/m 2 or less, the Al concentration is 0.50 mass % or more and 3.00 mass % or less, and the remainder consists of Zn and impurities.

Claims (77)

1 . A zinc-plated steel sheet for hot stamping comprising a steel sheet and a zinc plating film disposed on the steel sheet,

wherein the steel sheet includes, as a chemical composition, by mass %:

C: 0.02% to 0.58%;

Mn: 0.10% to 3.00%;

sol. Al: 0.001% to 1.000%;

Si: 0.28% or less;

P: 0.100% or less;

S: 0.005% or less;

N: 0.0100% or less;

Ti: 0% to 0.200%;

Nb: 0% to 0.200%;

V: 0% to 1.00%;

W: 0% to 1.00%;

Cr: 0% to 1.00%;

Mo: 0% to 1.00%;

Cu: 0% to 1.00%;

Ni: 0% to 1.00%;

B: 0% to 0.0100%;

Ca: 0% to 0.05%;

REM: 0% to 0.05%; and

a remainder comprising Fe and impurities, and

in the zinc plating film prior to hot stamping,

a plating adhesion amount is 15.0 g/m 2 or more and 30.0 g/m 2 or less,

a Fe concentration is 1.5 mass % or more and 4.7 mass % or less,

an Al content is 100 mg/m 2 or more and 400 mg/m 2 or less,

an Al concentration is 0.50 mass % or more and 3.00 mass % or less, and

a remainder consists of Zn and impurities.

2 . The zinc-plated steel sheet for hot stamping according to claim 1 ,

wherein the chemical composition of the steel sheet includes, by mass %, one or more of:

Ti: 0.005% to 0.200%;

Nb: 0.005% to 0.200%;

V: 0.10% to 1.00%;

W: 0.10% to 1.00%;

Cr: 0.05% to 1.00%;

Mo: 0.05% to 1.00%;

Cu: 0.05% to 1.00%;

Ni: 0.05% to 1.00%;

B: 0.0010% to 0.0100%;

Ca: 0.0005% to 0.05%; and

REM: 0.0005% to 0.05%.

3 . A method of manufacturing the zinc-plated steel sheet for hot stamping according to claim 1 , the method comprising processes that are sequentially performed, the processes including:

a heating process of heating a slab having the chemical composition according to claim 1 at 1200° C. or higher for 5 minutes or longer;

a hot-rolling process of hot-rolling the slab such that a finish rolling temperature is 800° C. or higher and 980° C. or lower and coiling the hot-rolled slab at a coiling temperature of 450° C. or higher and 800° C. or lower to obtain a hot-rolled steel sheet;

a cold-rolling process of pickling the hot-rolled steel sheet and subsequently cold-rolling the hot-rolled steel sheet such that a cumulative rolling reduction is 30% or higher and 80% or lower to obtain a cold-rolled steel sheet; and

a zinc plating process of annealing the cold-rolled steel sheet in a temperature range of 700° C. or higher and 900° C. or lower to obtain a steel sheet and dipping the steel sheet in a molten zinc bath having an Al concentration of 0.155 mass % or more and 0.175 mass % or less for 1.0 second or longer and 15.0 seconds or shorter to form a zinc plating film on the steel sheet.

4 . A method of manufacturing the zinc-plated steel sheet for hot stamping according to claim 2 , the method comprising processes that are sequentially performed, the processes including:

a heating process of heating a slab having the chemical composition according to claim 2 at 1200° C. or higher for 5 minutes or longer;

a hot-rolling process of hot-rolling the slab such that a finish rolling temperature is 800° C. or higher and 980° C. or lower and coiling the hot-rolled slab at a coiling temperature of 450° C. or higher and 800° C. or lower to obtain a hot-rolled steel sheet;

a cold-rolling process of pickling the hot-rolled steel sheet and subsequently cold-rolling the hot-rolled steel sheet such that a cumulative rolling reduction is 30% or higher and 80% or lower to obtain a cold-rolled steel sheet; and

a zinc plating process of annealing the cold-rolled steel sheet in a temperature range of 700° C. or higher and 900° C. or lower to obtain a steel sheet and dipping the steel sheet in a molten zinc bath having an Al concentration of 0.155 mass % or more and 0.175 mass % or less for 1.0 second or longer and 15.0 seconds or shorter to form a zinc plating film on the steel sheet.

5 . A zinc-plated steel sheet for hot stamping comprising a steel sheet and a zinc plating film disposed on the steel sheet,

wherein the steel sheet includes, as a chemical composition, by mass %:

C: 0.02% to 0.58%;

Mn: 0.10% to 3.00%;

sol. Al: 0.001% to 1.000%;

Si: 0.28% or less;

P: 0.100% or less;

S: 0.005% or less;

N: 0.0100% or less;

Ti: 0% to 0.200%;

Nb: 0% to 0.200%;

V: 0% to 1.00%;

W: 0% to 1.00%;

Cr: 0% to 1.00%;

Mo: 0% to 1.00%;

Cu: 0% to 1.00%;

Ni: 0% to 1.00%;

B: 0% to 0.0100%;

Ca: 0% to 0.05%;

REM: 0% to 0.05%; and

a remainder comprising Fe and impurities, and

in the zinc plating film prior to hot stamping,

a plating adhesion amount is 15.0 g/m 2 or more and 30.0 g/m 2 or less,

a Fe concentration is 1.5 mass % or more and 4.7 mass % or less,

an Al content is 100 mg/m 2 or more and 400 mg/m 2 or less,

an Al concentration is 0.50 mass % or more and 3.00 mass % or less, and

a remainder comprises Zn and impurities.