Title:
WELDING JOINT HAVING EXCELLENT FATIGUE CHARACTERISTICS IN ULTRA-HIGH STRENGTH HOT-ROLLED STEEL AND MANUFACTURING METHOD FOR SAME
Document Type and Number:
WIPO Patent Application WO/2019/124871
Kind Code:
A1
Abstract:
The present invention relates to a welding joint having excellent fatigue characteristics in ultra-high strength hot-rolled steel and a manufacturing method for the same. One embodiment of the present invention provides a welding joint having excellent fatigue characteristics in ultra-high strength hot-rolled steel and a manufacturing method for the same, the welding joint comprising: a welding bead formed by partially overlapping multiple sheets of steel and then welding the overlapping area; and a base material molten portion formed in an area within 2.0 mm forward distant from the end of the welding bead and on a part of the lower portion of the welding bead, wherein the base material molten portion has a minimum hardness of 370 Hv or more and a maximum hardness of 420 Hv or more, and the welding bead has an average hardness of 350 Hv or more. According to an aspect of the present invention, it is possible to effectively improve fatigue characteristics of a welding portion having a tensile strength of 1 GPa or more and a thickness of 6 mm or less in ultra-high strength hot-rolled steel. Therefore, the present invention can be preferably applied to a vehicular chassis component or the like.
Inventors:
BAE GYU-YEOL (KR)
KIM CHUNG-HA (KR)
KIM CHUNG-HA (KR)
Application Number:
PCT/KR2018/015816
Publication Date:
June 27, 2019
Filing Date:
December 13, 2018
Export Citation:
Assignee:
POSCO (KR)
International Classes:
B23K31/02; B23K9/02; B23K9/167; B23K28/02; B23K101/00
Domestic Patent References:
| WO2017018492A1 | 2017-02-02 |
Foreign References:
| JP2011062718A | 2011-03-31 | |||
| JP2004209513A | 2004-07-29 | |||
| JP2013226600A | 2013-11-07 | |||
| KR20160077325A | 2016-07-04 |
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
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