Claims
- 1. A method of producing a thin steel sheet adapted for drawing, comprising subjecting a cold rolled thin steel, which has a composition containing 0.001-0.010% by weight of C, not more than 1.0% by weight of Mn, not more than 1.2% by weight of Si, not more than 0.1% by weight of P, not more than 0.02% by weight of S and not more than 0.01% by weight of N, and further containing effective Ti in an amount larger than (4 times amount of [C] content minus 0.015% by weight ) but smaller than (4 times amount of [C] content plus 0.05% by weight) said effective Ti being remaining Ti after (48/32[S]+48/14[N])% by weight of Ti is substracted from the total amount of Ti depending upon the [S] and [N] contents in the steel, to a continuous annealing under a condition that the sheet is heated at a temperature, which lies within the range of from 850.degree. to 950.degree. C. and further lies within the range of from 850.degree. C.+(70/0.05){[effective Ti]% by weight-4% by weight .degree. C. to 950.degree. C.+(100/0.015){[effective Ti] % by weight -4[C]% by weight}.degree. C. depending upon the amount of [effective Ti] and [C] content, for a period of from 10 seconds to 5 minutes, and the above heated sheet is rapidly cooled at a cooling rate of at least 10.degree. C. per second within the temperature range of 850.degree.-500.degree. C. during the cooling step following to the heating, so as to obtain the thin steel sheet having a striking energy-absorbing property of at least 6 kgm/cm.sup.2 in a Charpy impact test at -100.degree. C., a r value of at least 1.8 and a baking hardenability of at least 4 kg/mm.sup.2.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-165315 |
Nov 1980 |
JPX |
|
Parent Case Info
This is a continuation-in-part of co-pending application Ser. No. 545,105 filed on Oct. 24, 1983 now abandoned, which is a continuation of Ser. No. 403,617 filed July 23, 1982, now abadoned.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/JP81/00353 |
11/21/1981 |
|
|
7/23/1982 |
7/23/1982 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO82/01893 |
6/10/1982 |
|
|
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4315783 |
Akisve et al. |
Feb 1982 |
|
Foreign Referenced Citations (2)
Number |
Date |
Country |
25891 |
Aug 1975 |
JPX |
104417 |
Aug 1979 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
403617 |
Jul 1982 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
545105 |
Oct 1983 |
|