JP2006021206A - Steel casting having part repaired by welding, and method for repairing steel casting by welding - Google Patents

Steel casting having part repaired by welding, and method for repairing steel casting by welding Download PDF

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JP2006021206A
JP2006021206A JP2004199488A JP2004199488A JP2006021206A JP 2006021206 A JP2006021206 A JP 2006021206A JP 2004199488 A JP2004199488 A JP 2004199488A JP 2004199488 A JP2004199488 A JP 2004199488A JP 2006021206 A JP2006021206 A JP 2006021206A
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welding
weld
buttering
layer
steel casting
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Masao Okazaki
正雄 岡崎
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Kansai Electric Power Co Inc
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Abstract

<P>PROBLEM TO BE SOLVED: To improve the crack occurrence resistance characteristic after the repair without stress relieving annealing. <P>SOLUTION: A method for repairing a steel casting by welding comprises a step of performing grooving by removing defects in the steel casting, a step of performing buttering welding by the coated electrode welding to a grooved part 3, a step of forming an initial layer buttering weld 12 by performing the half-bead method to cut and remove a part of the weld metal by the buttering welding from the surface in the thickness direction, and a step of forming second and subsequent permanent welds 14 by the TIG welding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は耐き裂発生特性に優れた溶接補修部を備えた鋳鋼品及び鋳鋼品の溶接補修方法に関する。   The present invention relates to a cast steel product having a weld repair portion having excellent crack resistance and a weld repair method for the cast steel product.

タービン車室、弁等の鋳鋼品には、装置の運転中に発生する温度や応力によりクリープ損傷や疲労損傷が発生する。き裂が発生し、さらに進展すると、タービン車室、弁等の破壊に繋がり、安全運転上問題となる。これらの損傷は鋳鋼品材中に存在する鋳造欠陥などからのき裂によることが多いため、これらの欠陥は浸透探傷、磁粉探傷、超音波探傷などの欠陥検査方法により調査され、ガウジングなどの方法により除去される。欠陥が除去された跡は溶接補修された後、運転に供与される。   In cast steel products such as turbine casings and valves, creep damage and fatigue damage occur due to temperature and stress generated during operation of the apparatus. If a crack occurs and further develops, it will lead to destruction of the turbine casing, valves, etc., which will cause a problem in safe driving. Since these damages are often caused by cracks from casting defects that exist in cast steel products, these defects are investigated by defect inspection methods such as penetrating flaw detection, magnetic particle flaw detection, ultrasonic flaw detection, and methods such as gouging. Is removed. After the defect has been removed, it is repaired by welding and then given to the operation.

従来の溶接補修方法は、被覆アーク溶接により、溶接ビードを積み重ねることにより行われていた。この補修方法では、被覆アーク溶接時の入熱により溶接部に残留応力が発生し、且つ母材の溶接熱影響部の最高硬さが増大する。このままでは、その後の装置の運転中にき裂が発生する可能性が高い。従って、溶接部の残留応力を除去し、且つ、母材の溶接熱影響部の最高硬さを低減するために、一般的に溶接後に応力除去焼鈍が必要である。応力除去焼鈍を行うためには、タービン車室や弁等の鋳鋼品を製造工場に持ち帰り電気炉内等で均一に加熱する必要があり、多額の費用を要する。   A conventional welding repair method has been performed by stacking weld beads by covering arc welding. In this repair method, residual stress is generated in the weld due to heat input during the covering arc welding, and the maximum hardness of the weld heat affected zone of the base material is increased. In this state, there is a high possibility that a crack will occur during the subsequent operation of the apparatus. Therefore, in order to remove the residual stress of the welded portion and reduce the maximum hardness of the weld heat affected zone of the base material, generally stress relief annealing is required after welding. In order to perform stress relief annealing, it is necessary to bring cast steel products such as turbine casings and valves to the manufacturing plant and heat them uniformly in an electric furnace, which requires a large amount of money.

母材の溶接熱影響部の硬さを低下させ、き裂の発生を抑制する補修方法として、被覆アーク溶接によりバタリング溶接を行い、その後、溶接金属層をその表面から厚さ方向に約１／２だけ研削除去するハーフビード法を行って初層バタリング溶接部を形成する方法が開発され、一部実際に適用されている。このように形成された初層バタリング溶接部の上に、被覆アーク溶接により第２層目以降の本溶接部を形成する。この補修方法によれば、第２層の溶接時の熱による焼戻し効果により、初層溶接時に形成された、硬化した溶接熱影響部を軟化させることができるので、応力除去焼鈍を行わなくても溶接熱影響部の最高硬さを下げることができる。   As a repair method that reduces the hardness of the weld heat-affected zone of the base metal and suppresses the occurrence of cracks, buttering welding is performed by covered arc welding, and then the weld metal layer is approximately 1 / thickness from the surface in the thickness direction. A method of forming a first layer buttering weld by performing a half bead method of grinding and removing only 2 has been developed and partially applied. On the first layer buttering weld formed in this way, the second and subsequent main welds are formed by covered arc welding. According to this repair method, the hardened weld heat affected zone formed at the first layer welding can be softened by the tempering effect due to the heat at the time of welding the second layer. The maximum hardness of the heat affected zone can be lowered.

しかしながら、ハーフビード法により初層バタリング溶接部を形成した後本溶接部を形成する上記の従来の補修方法では、実際には残留応力を十分に除去できず、また、溶接熱影響部の硬さを十分に低下させることはできない。その結果、その後のき裂の発生を完全に防止することができず、補修後の運転途中で再補修などが必要になるという問題があった。   However, in the above conventional repair method in which the main weld is formed after the first layer buttering weld is formed by the half bead method, the residual stress cannot actually be sufficiently removed, and the hardness of the heat affected zone is reduced. It cannot be reduced sufficiently. As a result, there was a problem that subsequent cracks could not be completely prevented, and re-repair was required during operation after repair.

本発明は上述の従来の問題点に鑑み、応力除去焼鈍が不要なハーフビード法を用いながら、補修後の装置運転中のき裂の発生をさらに抑制することが可能な耐き裂発生特性に優れた溶接補修箇所を備えた鋳鋼品及び鋳鋼品の溶接補修方法を提供することを目的とする。   In view of the above-mentioned conventional problems, the present invention is excellent in crack resistance characteristics that can further suppress the generation of cracks during operation of the apparatus after repair while using a half bead method that does not require stress relief annealing. An object of the present invention is to provide a cast steel product having a weld repair point and a weld repair method for the cast steel product.

本発明の溶接補修箇所を備えた鋳鋼品は、被覆アーク溶接によるバタリング溶接後、前記バタリング溶接による溶接金属の一部を表面から厚さ方向に切削除去するハーフビード法を行うことにより形成された初層バタリング溶接部と、ＴＩＧ溶接による第２層以降の本溶接部とを含むことを特徴とする。   The cast steel product having the weld repair location of the present invention is the first formed by performing a half bead method in which a part of the weld metal by the buttering welding is cut and removed from the surface in the thickness direction after the buttering welding by the covering arc welding. It includes a layer buttering weld and a main weld after the second layer by TIG welding.

また、本発明の鋳鋼品の溶接補修方法は、鋳鋼品中の欠陥部を除去して、開先加工する工程と、前記開先加工した部分に被覆アーク溶接によりバタリング溶接を行う工程と、前記バタリング溶接による溶接金属の一部を表面から厚さ方向に切削除去するハーフビード法を行い、初層バタリング溶接部を形成する工程と、ＴＩＧ溶接による第２層以降の本溶接部を形成する工程とを備えることを特徴とする。   Further, the welding repair method of the cast steel product of the present invention includes a step of removing a defect portion in the cast steel product and performing groove processing, a step of performing buttering welding by covering arc welding on the groove processed portion, A process of forming a first layer buttering weld by performing a half bead method in which a part of the weld metal by buttering welding is cut and removed from the surface in a thickness direction, and a process of forming a main weld after the second layer by TIG welding; It is characterized by providing.

本発明によれば、ハーフビード法により初層バタリング溶接部を形成し、その後、ＴＩＧ溶接により第２層以降の本溶接部を形成するので、溶接部の残留応力と母材の溶接熱影響部の最高硬さとをともに低減することができる。従って、その後の運転時に発生するき裂を経済的に防止でき、安全運転が可能となる。   According to the present invention, the first layer buttering weld is formed by the half bead method, and then the second and subsequent main welds are formed by TIG welding, so that the residual stress of the weld and the weld heat affected zone of the base metal Both the maximum hardness can be reduced. Therefore, the crack which generate | occur | produces at the time of subsequent driving | operation can be prevented economically, and safe driving | operation is attained.

本発明の溶接補修方法を図１を用いて説明する。   The welding repair method of this invention is demonstrated using FIG.

まず、タービン車室、弁等の鋳鋼品の母材１に存在する鋳造欠陥などの欠陥部をガウジングなどの方法により除去し、図１（Ａ）に示すような開先形状３を形成（開先加工）する。   First, defects such as casting defects existing in the base material 1 of a cast steel product such as a turbine casing and a valve are removed by a method such as gouging to form a groove shape 3 as shown in FIG. Pre-processing).

次に、図１（Ｂ）に示すように、開先加工した部分に、第１層（初層）として、被覆アーク溶接棒によりバタリング溶接層１１を形成する。   Next, as shown in FIG. 1 (B), a buttering weld layer 11 is formed as a first layer (first layer) with a covered arc welding rod in the grooved portion.

次に、図１（Ｃ）に示すように、バタリング溶接層１１の一部（全厚さの約１／２）を表面から厚さ方向に切削除去する。かくして、初層バタリング溶接部１２を得る。   Next, as shown in FIG. 1C, a part of the buttering weld layer 11 (about ½ of the total thickness) is cut and removed from the surface in the thickness direction. Thus, the first layer buttering weld 12 is obtained.

このように、被覆アーク溶接棒によりバタリング溶接した後、バタリング溶接層１１の一部を表面から厚さ方向に切削除去するハーフビード法を行って初層バタリング溶接部１２を形成する理由は以下の通りである。被覆アーク溶接棒により初層バタリング溶接を行うと、この溶接時の入熱により溶接部に残留応力が発生し、また母材の溶接熱影響部の最高硬さが増大する。初層溶接金属の切削除去をしないで第２層溶接を行うと、溶接熱影響部に第２層溶接時の熱による焼戻し効果を十分に作用させることができず、その結果、残留応力を低減し且つ溶接熱影響部を十分に軟化させることができない。ハーフビード法によりバタリング溶接層１１の切削除去を行うと、第２層溶接時の熱を溶接熱影響部に効果的に作用させることができる。バタリング溶接層１１をほぼ全て切削除去するフルビード切削除去を行えば残留応力の低減と溶接熱影響部の軟化とは十分に達成されるが、切削の時間、費用が増加し経済的でないためハーフビード法とする。   The reason why the first layer buttering weld 12 is formed by performing the half bead method in which a part of the buttering weld layer 11 is cut and removed from the surface in the thickness direction after buttering welding with the coated arc welding rod is as follows. It is. When first layer buttering welding is performed with a covered arc welding rod, residual stress is generated in the weld due to heat input during the welding, and the maximum hardness of the weld heat affected zone of the base metal increases. If the second layer welding is performed without removing the first layer weld metal, the tempering effect due to the heat during the second layer welding cannot be sufficiently applied to the weld heat affected zone, resulting in a reduction in residual stress. In addition, the weld heat affected zone cannot be sufficiently softened. When the buttering weld layer 11 is cut and removed by the half bead method, the heat during the second layer welding can be effectively applied to the weld heat affected zone. If full bead cutting removal is performed to cut and remove almost all of the buttering weld layer 11, reduction of residual stress and softening of the heat affected zone can be sufficiently achieved. However, since the cutting time and cost increase and it is not economical, the half bead method And

次に、図１（Ｄ）に示すように、初層バタリング溶接部１２上に、ＴＩＧ溶接により第２層溶接部１３を形成し、更に、図１（Ｅ）に示すように、ＴＩＧ溶接によりビードを積み重ねて第２層溶接部１３を含む本溶接部１４を形成する。   Next, as shown in FIG. 1 (D), a second layer welded portion 13 is formed by TIG welding on the first layer buttering welded portion 12, and further, as shown in FIG. 1 (E), by TIG welding. The main weld 14 including the second layer weld 13 is formed by stacking the beads.

第２層以降の本溶接部１４をＴＩＧ溶接により形成する理由は以下の通りである。本溶接部１４を被覆アーク溶接により形成すると、入熱量が大きいため、溶接部に発生する残留応力が増加すること、及び母材の溶接熱影響部の最高硬さが増加することにより、補修後の運転中に鋳鋼品中にき裂が発生する可能性が増大する。これに対して、ＴＩＧ溶接は入熱量が相対的に小さいので、溶接部に発生する残留応力及び母材の溶接熱影響部の最高硬さをともに低下させることができる。   The reason why the second and subsequent main welds 14 are formed by TIG welding is as follows. When the main weld 14 is formed by covered arc welding, since the heat input is large, the residual stress generated in the weld is increased, and the maximum hardness of the weld heat affected zone of the base material is increased. This increases the possibility of cracks occurring in the cast steel product during operation. On the other hand, since the amount of heat input is relatively small in TIG welding, it is possible to reduce both the residual stress generated in the weld and the maximum hardness of the weld heat affected zone of the base material.

タービン車室、弁等に使用されるＣｒＭｏＶ鋳鋼に表１に示す溶接材料及び溶接条件で溶接補修部を作成した。   A weld repair part was created on the CrMoV cast steel used in the turbine casing, valves, etc. using the welding materials and welding conditions shown in Table 1.

Figure 2006021206
Figure 2006021206

詳細は以下の通りである。   Details are as follows.

（実施例１）
図１（Ａ）に示すように母材１としてＣｒＭｏＶ鋳鋼を用い、開先加工を行った。開先形状の寸法は図２に示す通りである。 Example 1
As shown in FIG. 1A, groove processing was performed using CrMoV cast steel as the base material 1. The dimensions of the groove shape are as shown in FIG.

次に、図１（Ｂ）に示すように、開先加工した部分に、第１層（初層）として、被覆アーク溶接（ＳＭＡＷ）によりバタリング溶接層１１を形成した。使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料（溶接棒）の直径はφ２．６ｍｍであった。溶接に先立って溶接予定箇所を２００〜２５０℃（予熱パス間温度）に加熱した。   Next, as shown in FIG. 1B, a buttering weld layer 11 was formed as a first layer (first layer) by covering arc welding (SMAW) in the grooved portion. The welding material used was JIS Z3223 DT2315 or equivalent, and the diameter of the welding material (welding bar) was 2.6 mm. Prior to welding, the planned welding location was heated to 200 to 250 ° C. (temperature between preheating passes).

次に、図１（Ｃ）に示すように、バタリング溶接層１１の厚さの約１／２を表面から厚さ方向に切削除去（ハーフビード除去）して、初層バタリング溶接部１２を得た。   Next, as shown in FIG. 1C, about 1/2 of the thickness of the buttering weld layer 11 was cut and removed from the surface in the thickness direction (half bead removal) to obtain the first layer buttering weld 12. .

次に、図１（Ｅ）に示すように、本溶接部１４を形成した。本溶接部１４の形成は、ＴＩＧ溶接とし、使用した溶接材料はＪＩＳ Ｚ３３１６ ＹＧＴ１ＣＭ相当品とし、溶接材料（溶接棒）の直径はφ２．４ｍｍとした。溶接に先立って溶接予定箇所を３５０〜４００℃（予熱パス間温度）に加熱した。   Next, as shown in FIG. 1E, a main weld 14 was formed. The main weld 14 was formed by TIG welding, the welding material used was JIS Z3316 YGT1CM equivalent, and the diameter of the welding material (welding rod) was 2.4 mm. Prior to welding, the planned welding location was heated to 350 to 400 ° C. (temperature between preheating passes).

その後、応力除去焼鈍処理（ＳＲ処理）を行うことなく、溶接補修箇所を得た。   Then, the welding repair location was obtained, without performing stress removal annealing treatment (SR processing).

（比較例１）
初層のバタリング溶接層１１の形成に使用した溶接材料（溶接棒）の直径をφ３．２ｍｍと太くした点、及び本溶接部１４を被覆アーク溶接（ＳＭＡＷ）により形成した点を除いて実施例１と同様とした。本溶接に使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料（溶接棒）の直径はφ４ｍｍであった。この比較例１は、「背景技術」の欄に記載したハーフビード法を適用した従来の溶接補修方法に該当する。 (Comparative Example 1)
Except for the point that the diameter of the welding material (welding rod) used for forming the first buttering weld layer 11 was increased to φ3.2 mm, and the point where the main weld 14 was formed by covered arc welding (SMAW). Same as 1. The welding material used for the main welding was JIS Z3223 DT2315 or equivalent, and the diameter of the welding material (welding rod) was 4 mm. Comparative Example 1 corresponds to a conventional welding repair method to which the half bead method described in the “Background Art” column is applied.

（比較例２）
初層のバタリング溶接層１１の形成に使用した溶接材料（溶接棒）の直径をφ３．２ｍｍと太くした点、初層のビード削りをハーフビード除去に代えてフルビード除去とした点、及び、本溶接部１４を比較例１と同じ被覆アーク溶接（ＳＭＡＷ）により形成した点を除いて実施例１と同様とした。上記比較例１とは、フルビード除去を行った点で相違する。 (Comparative Example 2)
The diameter of the welding material (weld rod) used to form the first layer buttering weld layer 11 is increased to φ3.2 mm, the bead shaving of the first layer is replaced with full bead removal, and main welding. Example 14 was the same as Example 1 except that the part 14 was formed by the same coated arc welding (SMAW) as in Comparative Example 1. It differs from the said comparative example 1 by the point which performed full bead removal.

即ち、実施例１と同様に、図３（Ａ）に示すように母材１としてＣｒＭｏＶ鋳鋼を用い、開先加工を行った。   That is, as in Example 1, as shown in FIG. 3A, groove processing was performed using CrMoV cast steel as the base material 1.

次に、図３（Ｂ）に示すように、開先加工した部分に、第１層（初層）として、被覆アーク溶接（ＳＭＡＷ）によりバタリング溶接層１１を形成した。使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料（溶接棒）の直径はφ３．２ｍｍであった。溶接に先立って溶接予定箇所を２００〜２５０℃（予熱パス間温度）に加熱した。   Next, as shown in FIG. 3B, a buttering weld layer 11 was formed as a first layer (first layer) by covering arc welding (SMAW) in the grooved portion. The welding material used was JIS Z3223 DT2315 or equivalent, and the diameter of the welding material (welding bar) was 3.2 mm. Prior to welding, the planned welding location was heated to 200 to 250 ° C. (temperature between preheating passes).

次に、図３（Ｃ）に示すように、バタリング溶接層１１の大半を表面から厚さ方向に切削除去（フルビード除去）して、初層バタリング溶接部２２を得た。   Next, as shown in FIG. 3C, most of the buttering weld layer 11 was cut and removed from the surface in the thickness direction (full bead removal) to obtain the first layer buttering welded portion 22.

次に、図３（Ｄ）に示すように、初層バタリング溶接部２２上に第２層溶接部１３を形成し、更に、図３（Ｅ）に示すように更にビードを積み重ねて第２層溶接部１３を含む本溶接部１４を形成した。本溶接部１４の形成は、被覆アーク溶接（ＳＭＡＷ）とし、使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料の直径はφ４ｍｍとした。溶接に先立って溶接予定箇所を３５０〜４００℃（予熱パス間温度）に加熱した。   Next, as shown in FIG. 3 (D), the second layer welded portion 13 is formed on the first layer buttering welded portion 22, and the beads are further stacked as shown in FIG. 3 (E). A main weld 14 including the weld 13 was formed. The main weld 14 was formed by covered arc welding (SMAW), the welding material used was JIS Z3223 DT2315 equivalent, and the diameter of the welding material was φ4 mm. Prior to welding, the planned welding location was heated to 350 to 400 ° C. (temperature between preheating passes).

その後、応力除去焼鈍処理（ＳＲ処理）を行うことなく、溶接補修箇所を得た。   Then, the welding repair location was obtained, without performing stress removal annealing treatment (SR processing).

（比較例３）
バタリング溶接層１１の切削除去を行わなかった点、及び本溶接部１４を被覆アーク溶接（ＳＭＡＷ）により形成した点を除いて実施例１と同様とした。本溶接に使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料（溶接棒）の直径はφ２．６ｍｍであった。 (Comparative Example 3)
Example 1 was the same as Example 1 except that the buttering weld layer 11 was not cut off and the main weld 14 was formed by covered arc welding (SMAW). The welding material used for the main welding was JIS Z3223 DT2315 or equivalent, and the diameter of the welding material (welding rod) was 2.6 mm.

この比較例３の初層１１及び本溶接部１４で使用した溶接材料の直径は、何れも比較例１，２より細い。比較例３は、初層１１の溶接棒の直径を比較例１，２に比べて細くすることにより初層１１の厚さを薄くして、ビード削りを廃止し、更に本溶接部１４の溶接棒の直径を比較例１，２に比べて細くすることによりビード幅を小さくすることにより、本溶接時の焼戻し効果を比較例１，２に比べて高めることを意図している。   The diameters of the welding materials used in the first layer 11 and the main welded portion 14 of Comparative Example 3 are smaller than those of Comparative Examples 1 and 2. In Comparative Example 3, the diameter of the welding rod of the first layer 11 is made thinner than those of Comparative Examples 1 and 2, thereby reducing the thickness of the first layer 11 and eliminating bead cutting. By reducing the bead width by reducing the diameter of the rod as compared with Comparative Examples 1 and 2, it is intended to increase the tempering effect during main welding as compared with Comparative Examples 1 and 2.

（比較例４）
本溶接部１４を被覆アーク溶接（ＳＭＡＷ）により形成した点以外は実施例１と同様とした。本溶接に使用した溶接材料はＪＩＳ Ｚ３２２３ ＤＴ２３１５相当品とし、溶接材料（溶接棒）の直径はφ２．６ｍｍであった。 (Comparative Example 4)
Example 1 was the same as Example 1 except that the main weld 14 was formed by covered arc welding (SMAW). The welding material used for the main welding was JIS Z3223 DT2315 or equivalent, and the diameter of the welding material (welding rod) was 2.6 mm.

この比較例４は、比較例３とはハーフビード削りを行った点で相違する。比較例４は、これにより、本溶接時の焼戻し効果を比較例３に比べて高めることを意図している。   The comparative example 4 is different from the comparative example 3 in that half bead cutting is performed. The comparative example 4 intends to enhance the tempering effect during the main welding as compared with the comparative example 3 thereby.

（比較例５）
バタリング溶接層１１の切削除去を行わなかった点を除いて実施例１と同様とした。 (Comparative Example 5)
Except that the buttering weld layer 11 was not removed by cutting, the same procedure as in Example 1 was performed.

［評価］
実施例１及び比較例１〜５により得た溶接補修箇所について、残留応力、母材の溶接熱影響部の最高硬さ、引張り強さ、衝撃値（ＦＡＴＴ）を測定した。残留応力は引っ張り残留応力であって、母材の熱影響部をＸ線応力測定法で測定した。最高硬さは試料を厚さ方向に切断してビッカース硬度計を溶接熱影響部に切断面に直角方向に押し当てて測定した。 [Evaluation]
About the welding repair location obtained by Example 1 and Comparative Examples 1-5, the residual stress, the highest hardness of the heat-affected zone of the base metal, the tensile strength, and the impact value (FATT) were measured. Residual stress was tensile residual stress, and the heat-affected zone of the base material was measured by the X-ray stress measurement method. The maximum hardness was measured by cutting the sample in the thickness direction and pressing a Vickers hardness meter against the weld heat affected zone in a direction perpendicular to the cut surface.

評価結果を表２に示す。なお、表２において「−」は測定を行わなかったことを示している。   The evaluation results are shown in Table 2. In Table 2, “-” indicates that measurement was not performed.

Figure 2006021206
Figure 2006021206

表２より、本発明に対応する実施例１は、比較例１〜５に比べて、残留応力及び溶接熱影響部の最高硬さがともにバランス良く低下している。また、引張り強さ及び衝撃値（ＦＡＴＴ）に関しては、実施例１は比較例１，２，４と同等の良好な結果が得られており、問題無いことが分かる。従って、本発明によれば、応力除去焼鈍を行うことなく、残留応力が十分に除去され、且つ、溶接熱影響部の硬さが十分に低下した溶接補修箇所を形成することができる。 From Table 2, in Example 1 corresponding to the present invention, both the residual stress and the maximum hardness of the weld heat affected zone are reduced in a well-balanced manner as compared with Comparative Examples 1 to 5. Moreover, regarding the tensile strength and the impact value (FATT), Example 1 has obtained good results equivalent to those of Comparative Examples 1, 2, and 4, and it can be seen that there is no problem. Therefore, according to the present invention, it is possible to form a weld repair location where the residual stress is sufficiently removed and the hardness of the weld heat affected zone is sufficiently reduced without performing stress relief annealing.

本発明の利用分野は特に制限はないが、例えば発電装置のタービン車室、弁等の鋳鋼品の補修に利用することができる。   Although there is no restriction | limiting in particular in the utilization field of this invention, For example, it can utilize for repair of cast steel articles, such as a turbine casing of a power generator, a valve.

本発明の溶接補修方法の一実施形態を工程順に示した断面図である。It is sectional drawing which showed one Embodiment of the welding repair method of this invention in order of the process. 実施例１において形成した開先形状を示した断面図である。3 is a cross-sectional view showing a groove shape formed in Example 1. FIG. 比較例２に係る溶接補修方法を工程順に示した断面図である。It is sectional drawing which showed the welding repair method which concerns on the comparative example 2 in order of the process.

符号の説明Explanation of symbols

１ 母材
３ 開先形状
１１ バタリング溶接層
１２ 初層バタリング溶接部
１３ 第２層溶接部
１４ 本溶接部
DESCRIPTION OF SYMBOLS 1 Base material 3 Groove shape 11 Buttering welding layer 12 First layer buttering welding part 13 Second layer welding part 14 Main welding part

Claims (2)

被覆アーク溶接によるバタリング溶接後、前記バタリング溶接による溶接金属の一部を表面から厚さ方向に切削除去するハーフビード法を行うことにより形成された初層バタリング溶接部と、
ＴＩＧ溶接による第２層以降の本溶接部と
を含む溶接補修箇所を備えた鋳鋼品。 After the buttering welding by the covering arc welding, the first layer buttering welding part formed by performing a half bead method of cutting and removing a part of the weld metal by the buttering welding in the thickness direction from the surface;
A cast steel product having a weld repair location including the second and subsequent main welds by TIG welding. 鋳鋼品中の欠陥部を除去して、開先加工する工程と、
前記開先加工した部分に被覆アーク溶接によりバタリング溶接を行う工程と、
前記バタリング溶接による溶接金属の一部を表面から厚さ方向に切削除去するハーフビード法を行い、初層バタリング溶接部を形成する工程と、
ＴＩＧ溶接による第２層以降の本溶接部を形成する工程と
を備える鋳鋼品の溶接補修方法。
Removing the defective part in the cast steel product and performing the groove processing;
A step of performing buttering welding by covering arc welding on the grooved portion;
Performing a half bead method of cutting and removing a part of the weld metal by the buttering welding in the thickness direction from the surface, and forming a first layer buttering weld,
And a step of forming a main weld after the second layer by TIG welding.
JP2004199488A 2004-07-06 2004-07-06 Steel casting having part repaired by welding, and method for repairing steel casting by welding Withdrawn JP2006021206A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016112574A (en) * 2014-12-12 2016-06-23 中国電力株式会社 Crack repair method for cast steel member
CN106270937A (en) * 2016-09-20 2017-01-04 上海电气核电设备有限公司 A kind of overlay cladding repair method
EP3725457A1 (en) * 2019-04-17 2020-10-21 General Electric Company Turbine casing component and repair method therefor
CN111906414A (en) * 2020-07-08 2020-11-10 湖南华菱湘潭钢铁有限公司 Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container
CN113172361A (en) * 2021-05-12 2021-07-27 远景能源有限公司 Method and system for welding and repairing hub of wind generating set
CN113681125A (en) * 2021-08-31 2021-11-23 北京星航机电装备有限公司 Defect repairing method for special-shaped thin-wall oil storage structural part

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016112574A (en) * 2014-12-12 2016-06-23 中国電力株式会社 Crack repair method for cast steel member
CN106270937A (en) * 2016-09-20 2017-01-04 上海电气核电设备有限公司 A kind of overlay cladding repair method
EP3725457A1 (en) * 2019-04-17 2020-10-21 General Electric Company Turbine casing component and repair method therefor
US11708770B2 (en) 2019-04-17 2023-07-25 General Electric Company Turbine casing component and repair method therefor
CN111906414A (en) * 2020-07-08 2020-11-10 湖南华菱湘潭钢铁有限公司 Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container
CN111906414B (en) * 2020-07-08 2022-03-01 湖南华菱湘潭钢铁有限公司 Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container
CN113172361A (en) * 2021-05-12 2021-07-27 远景能源有限公司 Method and system for welding and repairing hub of wind generating set
CN113681125A (en) * 2021-08-31 2021-11-23 北京星航机电装备有限公司 Defect repairing method for special-shaped thin-wall oil storage structural part

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