US 12,337,408 B2Granted

Electrical steel strip friction stir welding method and method of producing electrical steel strip

AssigneeJfe Steel Corporation

InventorsMuneo Matsushita, Shohei Iwata, Kai Tomita

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Abstract

Provided is an electrical steel strip friction stir welding method that is able to inhibit the occurrence of coil joint fractures on a production line caused by deterioration of mechanical properties and shape of the coil joint while maintaining high work efficiency and that is also advantageous in terms of rotating tool durability. In the method, preheated double-sided friction stir welding is performed, diameter D (mm) of shoulders of rotating tools satisfies the relationship of the following Expression (7), and rotation speed RS (r/min) of the rotating tools, the diameter D (mm) of shoulders of the rotating tools, and joining speed JS (mm/min), expressed as RS×D3/JS, satisfy the relationship of the following Expression (8), 4×TJ≤D≤10×TJ . . . (7), and 180×TJ≤RS×D3/JS≤1500×TJ . . . (8).

Claims20

Dependent claims

An electrical steel strip friction stir welding method for joining a first electrical steel strip and a second electrical steel strip as a material to be joined by a pair of rotating tools facing each other, comprising:

a preheating process of preheating an unjoined portion of the material to be joined by a heating device disposed in front of the rotating tools in a joining direction on at least one side of the material to be joined;
and
a joining process of pressing the rotating tools into the unjoined portion of the material to be joined from both sides while rotating the rotating tools in opposite directions, and joining the first electrical steel strip and the second electrical steel strip by moving the rotating tools in the joining direction, wherein
the unjoined portion of the material to be joined is a butted portion or an overlapped portion between an end of the first electrical steel strip and an end of the second electrical steel strip following the first electrical steel strip,
the preheating process and the joining process are performed continuously by moving the heating device in the joining direction in conjunction with the rotating tools,
the diameter D (mm) of shoulders of the rotating tools satisfies the relationship of the following Expression (7), and
a rotation speed RS (r/min) of the rotating tools, the diameter D (mm) of the shoulders of the rotating tools, and a joining speed JS (mm/min), expressed as RS×D3/JS, satisfy the relationship of the following Expression (8),
4
×
TJ
≤
D
≤
10
×
TJ
(
7
)
180
×
TJ
≤
RS
×
D
3
/
JS
≤
1500
×
TJ
(
8
)
where TJ is defined such that,
when the unjoined portion is the butted portion, TJ is an average value (mm) of the thickness of the first electrical steel strip and the thickness of the second electrical steel strip, and
when the unjoined portion is the overlapped portion, TJ is the thickness (mm) of the overlapped portion.

36 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/704,917Filed 1 Aug 2022
Priority: JP 2021-19498830 Nov 2021
Published: US 2024/0424598 A126 Dec 2024
Granted: 24 Jun 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B23K 20/122
The heat being generated by friction; Friction welding: using a non-consumable tool, e.g. friction stir welding
B23K 20/1245
Using a non-consumable tool, e.g. friction stir welding: characterised by the apparatus
B23K 20/12
Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating: the heat being…
B23K 20/123
Using a non-consumable tool, e.g. friction stir welding: controlling or monitoring the welding process