JPH08318379A - Weld joint - Google Patents

Abstract

PURPOSE: To enhance strength of a weld zone by fabricating with cladding by welding in multilayers smoothly with the use of a filler metal harder than the material to be welded, in welding a structural joint, and thereby relaxing a stress concentration in the weld zone. CONSTITUTION: The flange 3 and the web 4 of a structural tee weld joint are vertically joined by electron beam welding. After the completion of the electron beam welding, the shape of the weld root and toe of the tee joint is formed in a smooth curve, by smoothly cladding by multilayer welding and by means of a welding method other than electron beam welding such as submerged arc welding or shield metal arc welding 2, using a filler metal with a higher yield stress than the material to be welded, in order to make the weld zone of the tee joint to be such a joint shape as to avoid an angle formed by straight lines which is liable to cause stress concentration. Further, enhancement in strength is contrived through surface working, for example, by smoothly working by grinding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welded joint manufactured by welding with a single welding pass in a plate thickness direction in a welded structure.

[0002]

2. Description of the Related Art In the conventional welded joint, a method of maintaining and improving the strength of the welded joint by controlling the welding method is generally used, as disclosed in Japanese Patent Laid-Open No. 170583/1989. However, little attention has been paid to the method of maintaining and improving the strength of the welded joint by changing the joint shape itself. In addition, JP-A-5
In JP-A-296257, the strength of the welded joint is improved by paying attention to the shape of the joint and creating a shape in which stress concentration is less likely to occur. However, no attention is paid to the material of the part.

[0003]

SUMMARY OF THE INVENTION According to the present invention, the strength of a welded joint portion produced by welding with a single welding pass in the plate thickness direction can be achieved at a weld root portion and a toe portion where cracks are relatively likely to occur. The stress concentration is alleviated, and the material of the part is made hard to increase the stress.

[0004]

In order to solve the above problems, in a welded joint manufactured by welding with a single welding pass in the plate thickness direction, the shapes of the welding root portion and the toe portion of the welded material are By welding other than the above using a filler material that is harder than the material, or by performing surface processing in addition to it, the stress concentration of the joint is relaxed, and the welding portion of the welded joint manufactured by the above welding is Improves strength and reliability.

[0005]

[Operation] A welded joint manufactured by a single welding pass in the plate thickness direction is liable to cause stress concentration at the weld root and toe of the welded joint. By smoothly overlaying the weld overlay by welding other than welding to form the shape of the weld root and toe of the weld joint smoothly, the stress concentration at the joint is relaxed,
In addition, the strength of the welded portion of the welded joint manufactured by the above welding can be improved by welding using a filler material that is harder than the material to be welded, and the reliability of the welded joint can be increased.

[0006]

Embodiments of the present invention will be described below.

FIG. 1 shows a sectional view of an electron beam welded joint structure as an example of a sectional view of a joint structure formed by welding with a single welding pass in the plate thickness direction according to the present invention. The flange 3 and the web 4 of the T-type welded joint are joined by electron beam welding 1. In this state, the flange 3 and the web 4 of the T-type welded joint are vertically joined as shown in the conventional welded joint structure by electron beam welding in FIG. 2, and the joint is also at a right angle. Since the stress concentration occurs, the welded joint has a reduced material strength. Therefore, after the electron beam welding is completed, as shown in FIG. 1, a welding method other than electron beam welding, for example, submerged arc welding or shield metal arc welding 2 is used to obtain a filler material having a higher yield stress than the welded material. In order to make the joint part of the T-type welded joint into a joint shape where straight lines where stress concentration is likely to occur and angles formed by straight lines cannot be used, the T-type welding The weld root and toe of the joint are formed on a smooth curve. As a result, the strength of the welding root portion and the toe portion of the T-type welded joint can be improved.

Further, the welding root portion and the toe portion after completion of the electron beam welding of the T-type welded joint are subjected to submerged arc welding or shield metal arc welding 2 by using a filler material having a higher yield stress than the material to be welded. When multi-layer welding is performed, the shape of the joint forms a smooth curve by the mass 201 of the welding path, as shown in FIG. Although the stress concentration is considerably reduced even in this state, as shown in FIG. 4, in order to make the joint shape such that there is no place such as a straight line and a straight line angle where the stress is more likely to occur, As shown in FIG. 4, the shape 2 of the welding root portion and the toe portion of the welded joint by surface processing, for example, grinder processing.
By smoothly processing 02, the stress concentration at the welding root portion and the toe portion of the welded joint can be relaxed, and the strength can be improved because a hard material is used.

Before joining the T-type welded joint by the electron beam welding 1 shown in FIG. 2, other than the electron beam welding as shown in FIG. 5, at positions corresponding to the welding root portion and the toe portion of the electron beam welding 1. In order to make the joint shape such that the straight line and the angle due to the straight line where the stress concentration is likely to occur by the electron beam welding 1 cannot be performed by using the welding method of 1), for example, submerged arc welding or shield metal arc welding 2, By overlaying the weld overlay with a material having a higher yield stress than the material to be welded and then performing electron beam welding 101 as shown in FIG.
By forming the shape of the weld root and toe of the welded joint smoothly, the stress concentration at the weld root and toe of the T-shaped welded joint due to electron beam welding is relaxed and the strength is improved. Can be made.

Further, after the end of the submerged arc welding or the shield metal arc welding 2 of the welding root portion and the toe portion of the T-type welded joint by the electron beam welding 1, straight lines and corners due to straight lines where stress concentration is likely to occur cannot be formed. In order to obtain such a joint shape, the shape of the welding root portion and the toe portion of the T-type welded joint is smoothly processed by a grinder process in advance, and then the electron beam 1 is used.
There is also a manufacturing method that can alleviate the stress concentration at the welding root portion and the toe portion of the welded joint and improve the strength.

FIG. 7 is a cross-sectional view of a T-type welded joint manufactured by the present invention using two flanges 301 and one web 4 using electron beam welding 102 and submerged arc welding 2. Is. Conventionally, as shown in FIG. 8, after the electron beam welding is completed, a straight line and an angle formed by the straight line are formed at the welding end portion, and that portion often causes a problem in strength. After the flange 301 and the two webs 4 are welded by electron beam welding 102, they are attached by submerged arc welding 2 using a filler material having a higher yield stress than the material to be welded, as shown in FIG. By making the portion have a smooth shape, the stress concentration of the T-type joint can be relaxed and the strength can be improved.

[0012]

EFFECTS OF THE INVENTION According to the present invention, a welding method capable of welding with a single welding pass in the plate thickness direction, for example, a welded joint manufactured by electron beam welding, has a welded joint portion of a shape other than the welding method. Method, for example, by submerged arc welding or shield metal arc welding, using a filler material with a higher yield stress than the material to be welded, smoothly overlay the weld overlay and weld root and toe of the weld joint. The stress concentration at the joint can be reduced by smoothly forming the shape of the weld joint, or by smoothing the shape of the weld root and toe of the weld joint by performing surface processing such as grinder processing in addition to that. And the strength of the welded part of the welded joint can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a welded joint structure according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional welded joint structure manufactured by a single welding pass in the plate thickness direction.

FIG. 3 is a perspective view of a welded joint structure showing a state of a multilayer welding pass of the electron beam welded joint structure.

FIG. 4 is a perspective view of the weld joint structure showing a state after surface treatment such as grinder processing of a multilayer welding pass of the electron beam weld joint structure.

FIG. 5 is a perspective view of a welded joint structure in which a shape in which stress concentration is relieved is overlay welded in advance.

FIG. 6 is a perspective view of a welded joint structure manufactured by electron beam welding after overlay welding a shape in which stress concentration is relaxed in advance.

FIG. 7 is a perspective view of a T-type welded joint structure manufactured by two flanges and one web.

FIG. 8 is a perspective view of a conventional T-type welded joint structure manufactured by two flanges and one web.

[Explanation of symbols]

 1, 2 ... Weld, 3 ... Flange, 4 ... Web.

Claims (4)

[Claims] 1. In a joint for a structure manufactured by welding, a welding root portion and a toe portion of a welded portion which has been welded by a single welding pass in a plate thickness direction are straight lines where stress concentration is likely to occur. In order to obtain a joint shape that does not allow straight corners, a welding method other than the above welding is used, and the yield stress when hardened is higher than the yield stress of the structure being welded A welded joint characterized in that the shape of the portion and the toe portion is formed into a smooth shape free from stress concentration. 2. In a joint of a structure manufactured by welding, a welding root portion and a toe portion of a welded portion which has been welded by one welding pass in the plate thickness direction are straight lines where stress concentration is likely to occur. In order to make the joint shape so that corners due to straight lines cannot be made, before completing the welding with one welding pass in the plate thickness direction, at the position corresponding to the welding root part and toe part by the above welding, the above welding Using a welding method other than, the yield stress when hardened is higher than the yield stress of the structure to be welded, and the weld overlay is preliminarily stacked on the shape without smooth stress concentration in advance. A welded joint and a method for manufacturing the same, wherein welding is performed, and finally, the shapes of the welding root portion and the toe portion formed by the above welding are formed into a smooth shape without stress concentration. 3. The joint of a structure manufactured by electron beam welding according to claim 1 or 2, wherein the welding root portion and toe portion of the welded portion after electron beam welding is completed, or welding before welding is performed. A welded joint that has a smooth shape with no stress concentration at the positions corresponding to the root and toe. 4. In a joint of a structure manufactured by welding, a welding root portion and a toe portion of a welded portion which has been welded by a single welding pass in the plate thickness direction are straight lines where stress concentration is likely to occur. After welding the welding root and the toe by using the method according to claim 1 or 2, the welding root and the toe are shaped so as to form a joint shape in which a straight corner is not formed. Welded joint that is processed smoothly.