Method for manufacturing metal sheet and rapid quenching unit

Patent metadata

Field	Value
Publication number	US-10760144-B2
Application number	US-201515531081-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Nov 28, 2014
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A method for manufacturing a metal sheet comprising pinching the metal sheet in rapid quenching between a pair of pinch rolls in the range where the temperature of the metal sheet is from (TMs+150) (° C.) to (TMf−150) (° C.), wherein the Ms temperature of the metal sheet is TMs (° C.) and the Mf temperature thereof is TMf (° C.), as well as a rapid quenching unit comprising a pair of pinch rolls capable of use in such a method.

First claim

The invention claimed is:

1. A quenching unit for cooling a metal sheet by immersing the metal sheet in a liquid, comprising a pair of pinch rolls and a water ejecting device for ejecting cooling water to a front surface and back surface of the metal sheet, wherein the pinch rolls are placed between the metal sheet and at least one nozzle of the water ejecting device in a direction perpendicular to a surface of the metal sheet, and wherein the pinch rolls pinch the metal sheet in the range where the temperature of the metal sheet is from (T Ms +150) (° C.) to (T Mf −150) (° C.),
T Ms (° C.) is a Ms temperature of the metal sheet, and
T Mf (° C.) is a Mf temperature thereof.

2. A method for manufacturing a metal sheet using a continuous annealing line including a quenching unit as recited in claim 1 for cooling the metal sheet by immersing the metal sheet in a liquid, the method comprising pinching the metal sheet in rapid quenching between the pair of pinch rods placed in the liquid in a range where a temperature of the metal sheet is from (T Ms +150) (° C.) to (T Ms ·150) (° C.), and ejecting cooling water with the water ejecting device to a front surface and back surface of the metal sheet, with the pinch rolls placed between the metal sheet and the at least one nozzle of the water electing device in the direction perpendicular to the respective surface of the metal sheet, and wherein
T Ms (° C.) is a Ms temperature at which the martensite transformation of the metal sheet starts,
T Ms (° C.) is a Mf temperature at which the martensite transformation thereof finishes.

3. The method for manufacturing the metal sheet according to claim 2 , wherein a pinch position of the pair of pinch rolls is set on the basis of a threading speed, a thickness, and a quenching start temperature of the metal sheet.

4. The method for manufacturing the metal sheet according to claim 3 , wherein a distance d (mm) from a water surface to a rotation center of the pinch roll is given by the following formula:

[

Math
.

⁢
1

]

v
×

t
⁡

(

T
-

T
Ms

-
150

)

1.5

≤
d
≤

v
×

t
⁡

(

T
-

T
Mf

+
150

)

1.5

T Ms (° C.) is the Ms temperature of the metal sheet,
T Mf (° C.) is Mf temperature of the metal sheet,
v (m/s) is a feed rate of the metal sheet,
t (mm) is a thickness of the metal sheet,
T (° C.) is a quenching start temperature, and
d (mm) is the distance from the water surface to the rotation center of each pinch roll.

5. The method for manufacturing the metal sheet according to claim 2 , wherein a distance d (mm) from a water surface to a rotation center of the pinch roll is given by the following formula:

[

Math
.

⁢
1

]

⁢

⁢

v
×

t
⁡

(

T
-

T
Ms

-
150

)

1.5

≤
d
≤

v
×

t
⁡

(

T
-

T
Mf

+
150

)

1.5

T Ms (° C.) is the Ms temperature of the metal sheet,
T Mf (° C.) is Mf temperature of the metal sheet,
v (m/s) is a feed rate of the metal sheet,
t (mm) is a thickness of the metal sheet,
T (° C.) is a quenching start temperature, and
d (mm) is the distance from the water surface to the rotation center of each pinch roll.

Assignees

• Jfe Steel Corp

Inventors

• Yoshimoto Soshi
• Miyake Masaru
• Takeda Gentaro

Classifications

• C21D9/5737

  Rolls; Drums; Roll arrangements · CPC title

• C21D9/562

  Details · CPC title

• C21D1/63

  for bath quenching · CPC title

• C21D9/573 Primary

  with cooling · CPC title

• C21D9/563 Primary

  Rolls; Drums; Roll arrangements · CPC title