EP0196788A2
Expired / Lapsed
EP
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Method of manufacturing formable as rolled thin steel sheets
Assignee: JFE Steel Corp
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Filing: 1986-02-28
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Granted: —
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Expires: 2006-02-28
Abstract
Abstract A method of manufacturing formable as-rolled thin steel sheets having excellent ridging resistance and other properties is disclosed, which comprises rolling a low carbon steel to a given thickness without cold rolling and recrytalli- zation annealing steps. In this rolling, at least one rolling pass is carried out within a given temperature range at high draft and high strain rate.
Inventors
- 👤 Susumu C/O Technical Research Division Satoh
- 👤 Saiji C/O Technical Research Division Matsuoka
- 👤 Takashi C/O Technical Research Division Obara
- 👤 Kozo C/O Technical Research Division Tsunoyama
- 👤 Toshio C/O Technical Research Division Irie
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 08:52
CPC Classifications
B; B21; B21B; B21B37/00; C; C21; C21D; C21D8/00; C21D8/02; C21D8/04; C21D8/0421; C21D8/0426; C21D7/00; B21B2201/00; B21B2201/04; C21D8/0431; C21D8/0447; C21D8/0463; C21D8/0478
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
67 words
A method of manufacturing formable as-rolled thin steel sheets having an improved ridging resistance through a step of rolling a low carbon steel to a given thickness, which comprises performing at least one rolling pass within a temperature range of from 500°C to Ar 3 transformation point at a draft of not less than 35% and a strain rate of not less than 300 sec -1 .
Claim 2
Independent Claim
67 words
A method of manufacturing formable as-rolled thin steel sheets having an improved ridging resistance through a step of rolling a low carbon steel to a given thickness, which comprises performing at least one rolling pass within a temperature range of from 500°C to Ar 3 transformation point at a draft of not less than 35% and a strain rate of not less than 300 sec -1 .
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein said rolling pass is carried out under a condition of ε̇≧0.5T+80 (i: strain rate, T: rolling temperature, °C).
Claim 4
Dependent Claim
24 words
The method according to claim 1, wherein said rolling pass is carried out under a condition of ε̇/µ≧1,000 (ε̇: strain rate, µ: friction coefficient).
Claim 5
Dependent Claim
16 words
The method according to claim 1, wherein said rolling pass is carried out under a tension.
Claim 6
Dependent Claim
24 words
The method according to claim 1, wherein the thin steel sheet after the rolling is coiled at a temperature of not more than 400°C.
Claim 7
Dependent Claim
26 words
The method according to claim 1, wherein said rolling pass is carried out under a condition of ε̇/R≧2.0 (ε̇: strain rate, R: radius of rolling roll).
Claim 8
Dependent Claim
33 words
The method according to claim 1, wherein the thin steel sheet after the rolling is coiled at a temperature of not more than 400°c and then subjected to a hot metal dipping treatment.
Claim 9
Independent Claim
71 words
A method of manufacturing formable as-rolled thin steel sheets having improved ridging resistance and deep drawability through a step of rolling a low carbon steel to a given thickness, which comprises performing at least one rolling pass within a temperature range of from 300°C to less than recrystallization temperature of ferrite at a draft of not less than 35% and a strain rate of not less than 300 sec -1 .
Claim 10
Independent Claim
71 words
A method of manufacturing formable as-rolled thin steel sheets having improved ridging resistance and deep drawability through a step of rolling a low carbon steel to a given thickness, which comprises performing at least one rolling pass within a temperature range of from 300°C to less than recrystallization temperature of ferrite at a draft of not less than 35% and a strain rate of not less than 300 sec -1 .
Claim 11
Dependent Claim
22 words
The method according to claim 1, wherein said low carbon steel has an iron content of not less than 99.50% by weight.
Claim 12
Dependent Claim
28 words
The method according to claim 1, wherein the thin steel sheet after the rolling is coiled and held at a temperature of 200-500°C for at least one minute.
Claim 13
Dependent Claim
34 words
The method according to claim 1, wherein the thin steel sheet after the rolling is subjected to a heat treatment at a temperature of not less than 500°C for not less than 0.2 second.
Claim 14
Dependent Claim
32 words
The method according to claim 1, wherein the thin steel sheet after the rolling is coiled at a temperature of not more than 400°C and then subjected to a metal electroplating treatment.
Claim 15
Dependent Claim
48 words
The method according to claim 1, wherein said rolling pass is carried out under a condition that the strain rate satisfies an equation (1) with respect to a critical strain rate represented by an equation (2): (ε̇: strain rate, ε̇ C : critical strain rate, T: rolling temperature).
References Cited (Backward Citations)
No citation records indexed.
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