JPH10153581A - Inspection method for high-frequency welded steel pipe, and its manufacturing equipment - Google Patents
Inspection method for high-frequency welded steel pipe, and its manufacturing equipmentInfo
- Publication number
- JPH10153581A JPH10153581A JP8311569A JP31156996A JPH10153581A JP H10153581 A JPH10153581 A JP H10153581A JP 8311569 A JP8311569 A JP 8311569A JP 31156996 A JP31156996 A JP 31156996A JP H10153581 A JPH10153581 A JP H10153581A
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- welded steel
- frequency welded
- frequency
- pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/044—Internal reflections (echoes), e.g. on walls or defects
Abstract
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は高周波溶接鋼管の検
査方法及びその製造装置に関し、特にステンレス鋼高周
波溶接管の分野における溶接欠陥の検出及び品質保証を
同時に行いつつステンレス鋼高周波溶接管（以下ステン
レス電縫管と称す）を製造する場合に用いて有用なもの
である。
【０００２】
【従来の技術】従来、ステンレス電縫管を含む高周波溶
接鋼管（以下電縫管と称す）の検査方法としては、抜き
取りによる確性検査及びインライン若しくはオフライン
での渦流探傷法，超音波探傷法等による検査が知られて
いる。これらのうち確性検査とは、抜き取った電縫管に
所定の偏平率の偏平歪みを与え、この状態で溶接部を目
視することによりその良否を検査する方法である。一
方、渦流探傷法は溶接部に流す渦電流の変化を検出する
ことにより、また超音波探傷法は溶接部に入射させる超
音波の反射状態を検出することによりそれぞれ溶接部の
良否を検査する方法である。これら渦流探傷法，超音波
探傷法では電縫管に偏平歪みは与えていない。
【０００３】また、特開昭６３−２４９０５０号公報に
おいては、溶接部に対して垂直方向に２５％以下の偏平
歪みを付加した後真円に戻し、溶接部の非破壊検査を行
なう検査方法が開示されている。
【０００４】
【発明が解決しようとする課題】上述の如き渦流探傷法
及び超音波探傷法では、高周波溶接鋼管特有の冷接欠陥
（コールドウエルド）、ペネトレイト欠陥は検出が難し
く、通常は抜き取りによる確性検査によって確認され
る。
【０００５】ところが、確性検査は抜き取りで行うので
電縫管の全長を検査することはできず、検査方法として
は信頼性に欠ける一面がある。すなわち、１００％品質
保証された電縫管を製造するには、その全長を対象とし
た、より確実な検査方法を確立する必要がある。
【０００６】また、溶接部に対して垂直方向に管径の２
５％以下の偏平歪みを付加する特開昭６３−２４９０５
０号公報に開示する検査方法では、与える偏平歪みの量
がステンレス電縫管に対しては不十分であるばかりでな
く、特にフェライト系ステンレス鋼を用いたステンレス
電縫管では溶接部の脆性遷移温度を考慮する必要があ
り、偏平歪みを与える時の温度を制御する必要がある。
【０００７】本発明は、上記従来技術に鑑み、電縫管の
溶接欠陥をインラインで検出し、製品の溶接部の品質を
１００％保証することができる高周波溶接鋼管の検査方
法及びその製造装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】上記目的を達成する本発
明は次の各種の実験に基づく知見を基礎するものであ
る。
【０００９】ペネトレータ・コールドウエルド等、溶接
欠陥を内在する溶接部は引張りの歪を与えることにより
溶接欠陥から開口して破壊に至る。造管ラインにおいて
電縫管の溶接部に対し引張歪を与えるためには、溶接部
に対し９０度方向から圧縮偏平加工を施せば溶接部に十
分な引張歪を付与することができる。かくして、ステン
レス電縫管の溶接欠陥率と偏平率との関係について調査
を行なった結果、溶接欠陥率と偏平率との関係を明らか
にすることができた。
【００１０】ここで溶接欠陥率は、図２に示す網点領域
であるコールドウエルド域の面積をｓ、突き合わせ部の
面積（肉厚ｔ×長さＬ）をＳとするとき、次式（１）で
表される。
溶接欠陥率＝（ｓ／Ｓ）×100 （％）・・・・・・・・（１）
【００１１】また偏平率は、図３（ａ）に示すように偏
平歪みを与える前のステンレス電縫管の外径Ｄ1 と、図
３（ｂ）に示すように偏平歪みを与えた後のステンレス
電縫管の短径側の外径Ｄ2 とを用いて次式（２）で表さ
れる。
偏平率＝（Ｄ1 −Ｄ2 ）／Ｄ1 ×100 （％）・・・・・（２）
【００１２】調査は次のような態様で行った。先ず、試
料となる多数のステンレス電縫管のそれぞれに、溶接部
から左右に９０度の位置でこのステンレス電縫管を挟ん
で径方向中心に向かう力に基づく偏平歪みを徐徐に付与
する。これを溶接部の割れが目視により確認できる時点
まで継続する。このようにして溶接部に割れを生起した
時点の式（２）で定義される偏平率を記録しておく。そ
の後試料を完全に潰し、溶接部を開いて顕微鏡で観察す
ることにより式（１）で定義される溶接欠陥率を求め
る。
【００１３】上述の如き調査により求めた溶接欠陥率と
偏平率との関係を図４に示す。同図に示す結果から、溶
接欠陥率が２〜３％でも偏平率が３０％までは溶接部の
割れを目視できない試料があることが分かる（図４の試
料参照）。すなわち偏平率が２５％だと溶接欠陥があ
っても溶接部が割れない場合がある。この逆に、偏平率
が３０％以上の偏平歪みを与えれば、溶接欠陥を内在し
た溶接部は全て割れが生じることを確認した。一方、Ｊ
ＩＳ規格では溶接欠陥率の如何にかかわらず偏平率が５
７％までは割れを生起しないことを要求している。した
がって、偏平率が３０％乃至６０％の偏平歪みを付与し
て割れが検出されない場合、実用上溶接欠陥のない良品
であると判断することができる。
【００１４】かかる知見に基づく本発明の構成は次の点
を特徴とする。
【００１５】１） 高周波溶接鋼管の製造ライン内にお
いて、高周波溶接鋼管の溶接部から左右に９０度の位置
でこの高周波溶接鋼管を挟んで径方向中心に向かう力を
付与することによりこの高周波溶接鋼管に偏平率３０％
乃至６０％の偏平歪みを与え、その後矯正ロールにより
真円に戻し、渦流探傷若しくは超音波探傷により溶接部
の割れを検出すること。
【００１６】２） アンコイラーから巻き戻した鋼板を
管状に成形するとともに突合せ部を高周波溶接し、その
後冷却することにより高周波溶接鋼管を得る高周波溶接
鋼管の製造装置において、冷却した高周波溶接鋼管にそ
の溶接部から左右に９０度の位置でこの高周波溶接鋼管
を挟んで径方向中心に向かう力を付与することによりこ
の高周波溶接鋼管に偏平率３０％乃至６０％の偏平歪み
を与える歪付与手段と、偏平歪みを付与した高周波溶接
鋼管を元の真円に戻す矯正手段と、真円に戻した高周波
溶接鋼管の溶接部の割れを検出する検査手段とを有する
こと。
【００１７】フェライト系ステンレス鋼は溶接部の脆性
遷移温度を考慮する必要があり、偏平歪みを与える時の
温度を制御する必要がある。この点を明らかにするため
に健全な溶接部、すなわち上述の如き偏平試験により割
れを生起しなかった溶接部にメカニカルにノッチを形成
し、かかる溶接部を有する試料を恒温室で種々の温度に
保持し、この状態で各試料に対するシャルビー衝撃試験
を行った。この結果を図６に示す。同図に示すように、
温度が１１０℃以上では常に大きな衝撃を与えなければ
割れが進展しないことが分かった。すなわち温度が１１
０℃以上では溶接欠陥を含んでいても延性を示す（１１
０℃近傍に脆性遷移温度がある）ので、インラインで偏
平歪みを付与する時には溶接部の温度を１１０℃以下に
制御する必要があることが明らかとなった。
【００１８】かかる知見に基づく本発明の他の構成は次
の点を特徴とする。
【００１９】３） 上記１）の高周波溶接鋼管の検査方
法において、高周波溶接鋼管がフェライト系ステンレス
鋼である場合において、この高周波溶接鋼管が１１０℃
以下になるように温度制御をした後、高周波溶接管に偏
平歪みを付与するようにしたこと。
【００２０】４） 上記２）の高周波溶接鋼管の製造装
置において、歪付与手段に供給する高周波溶接鋼管の温
度制御を行いその温度が１１０℃以下になるように冷却
する冷却手段を歪付与手段の前段に配設したこと。
【００２１】
【発明の実施の形態】以下本発明の実施の形態を図面に
基づき詳細に説明する。
【００２２】図１は本発明の実施の形態に係る高周波溶
接鋼管の製造装置を示す概略構成図である。本形態に係
る装置はステンレス電縫管の場合について説明するが、
これに限定するものではない。一般に電縫管の製造装置
として適用し得る。図１に示すように、本製造装置は、
アンコイラー１、成形ロール２、高周波溶接機３、クー
リング装置４、偏平ロール５、矯正ロール６、超音波探
傷装置７、走行切断機８及びランナアウトテーブル９を
有し、アンコイラー１から巻き戻したステンレス鋼板を
成形ロール２で成形して管状部材とし、その後高周波溶
接機３で突き合わせ部を高周波溶接してステンレス電縫
管を形成する。クーリング装置４は高周波溶接直後のス
テンレス電縫管を冷却するものであり、本形態ではこの
クーリング装置４の出口におけるステンレス電縫管の温
度が１１０℃以下になるように冷却する。このときの温
度は１１０℃以下であれば何度でもよいが、冷却効率及
び脆性遷移温度を併せて考慮すれば１１０℃以下でこの
近傍の温度が好適である。
【００２３】歪付与手段である偏平ロール５は、特にこ
の部分を抽出・拡大して図２に示すように、垂直軸５
ａ、５ｂ回りに回転可能に形成した相対向するオーバル
ロール５ｃ、５ｄ間に冷却したステンレス電縫管を通
し、その溶接部から左右に９０度の位置でこのステンレ
ス電縫管を挟んで径方向中心に向かう力を付与すること
によりこのステンレス電縫管に偏平率３０％の偏平歪み
を与えるものである。本形態では二段で所定の歪を付与
しているが、この段数に特別な制限はない。
【００２４】矯正ロール６は偏平歪みを付与したステン
レス電縫管を元の形状に戻すとともに真円に成形するも
のである。超音波探傷装置７は真円に戻したステンレス
電縫管の溶接部の割れを検出する検査手段である。これ
は渦電流探傷装置であっても勿論良い。超音波探傷装置
７で所定の検査を終えたステンレス電縫管は走行切断機
８で所定寸法に切断してランナアウトテーブル９に搬入
する。ランナアウトテーブル９では超音波探傷装置７に
よる検査の結果を受けてステンレス電縫管の良品と不良
品の仕分けも行う。
【００２５】図３は本形態の効果を確認するための試験
の結果を示す特性図である。図３中、黒丸のプロット点
は本実施の形態にかかる方法、すなわち所定のインライ
ン偏平歪みを付与した場合に超音波探傷装置７の探傷値
と溶接欠陥率との関係を調べたものである。同図中、白
丸のプロット点は他の条件は同じで、インライン偏平歪
みを付与しなかった場合に超音波探傷装置７の探傷値と
溶接欠陥率との関係を調べたものである。この試験はそ
れぞれの場合に探傷値を記録しておき、その後試料であ
る各ステンレス電縫管を完全に潰し、溶接部を開いて顕
微鏡で観察することにより上記式（１）で定義される溶
接欠陥率を求め、探傷値と対応させてプロットしたもの
である。この場合、探傷値が８０％とは出射した超音波
の８０％が透過して受信部で受信されたことを表してお
り、良品であると判定し得る。一方、探傷値が４０％以
下の場合は不良品であると判定する。この基準に依る場
合、インライン偏平歪みを付与しなかった場合には溶接
欠陥率が１５％程度でも探傷値は８０％（良品）となる
場合があり（試料参照）、溶接部の１００％の品質保
証はできないのに対し、本形態の如く所定のインライン
偏平歪みを付与した場合には溶接欠陥率が数％でも探傷
値は２０％程度（不良品）となり（試料参照）、溶接
部の１００％の品質保証が可能となることが分かる。
【００２６】なお、インライン偏平歪みを付与しなかっ
た場合でも試料、の如く探傷値が小さい、すなわち
不良品であると判定し得る領域にプロットされる場合も
あるが、これは矯正ロール６による矯正時に付与される
矯正歪みにより溶接部に割れを生起したものであると考
えられる。このように不良品であると判定される場合は
問題はないが、試料の如く溶接欠陥が内在するにもか
かわらず、超音波探傷では不良品であることを検出し得
ない場合が問題である。品質保証の精度が劣るからであ
る。
【００２７】
【発明の効果】以上実施の形態とともに詳細に説明した
通り、本発明によれば電縫管の製造中にインラインでそ
の溶接部の良否を完全に検出することができ、電縫管の
完全な品質保証を行うことができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a high-frequency welded steel pipe and an apparatus for producing the same, and more particularly to a method for simultaneously detecting a weld defect and assuring quality in the field of a high-frequency welded stainless steel pipe. It is useful when manufacturing a stainless steel high frequency welded pipe (hereinafter referred to as a stainless steel electric resistance welded pipe) while performing. Conventionally, high-frequency welded steel pipes (hereinafter referred to as "electrically welded pipes") including stainless steel electric resistance welded pipes have been inspected by a method such as reliability inspection by extraction, in-line or off-line eddy current flaw detection, and ultrasonic flaw detection. Inspection by the law is known. Among these, the accuracy test is a method of giving a flat strain of a predetermined flat rate to the extracted electric resistance welded tube, and visually inspecting the welded portion in this state to check the quality. On the other hand, the eddy current flaw detection method detects the change of eddy current flowing in the welded part, and the ultrasonic flaw detection method detects the quality of the welded part by detecting the reflection state of the ultrasonic wave incident on the welded part. It is. In the eddy current inspection method and the ultrasonic inspection method, no flat strain is given to the ERW pipe. Further, Japanese Patent Application Laid-Open No. 63-249050 discloses an inspection method in which a flattened strain of 25% or less is added to a welded portion in a vertical direction, and then the welded portion is returned to a perfect circle to perform a nondestructive inspection of the welded portion. It has been disclosed. [0004] In the eddy current flaw detection method and the ultrasonic flaw detection method as described above, it is difficult to detect a cold welding defect (penetrate defect) and a penetrate defect peculiar to a high-frequency welded steel pipe. Confirmed by inspection. However, since the accuracy inspection is performed by sampling, the entire length of the ERW tube cannot be inspected, and there is one aspect of the inspection method that lacks reliability. That is, in order to manufacture an electric resistance welded pipe with 100% quality assurance, it is necessary to establish a more reliable inspection method for the entire length. In addition, a pipe diameter of 2 mm
Japanese Patent Application Laid-Open No. 63-24905 in which a flat distortion of 5% or less is added.
In the inspection method disclosed in Japanese Patent Publication No. 0, the amount of flat strain to be given is not only insufficient for stainless steel ERW pipes, but also particularly in stainless steel ERW pipes made of ferritic stainless steel, the brittle transition of the welded portion. It is necessary to consider the temperature, and it is necessary to control the temperature at which the flat strain is applied. In view of the above prior art, the present invention provides a method for inspecting a high-frequency welded steel pipe capable of detecting welding defects in an ERW pipe in-line and guaranteeing the quality of a welded part of a product by 100%, and an apparatus for manufacturing the same. The purpose is to provide. The present invention, which achieves the above object, is based on knowledge based on the following various experiments. [0009] A weld having a welding defect, such as a penetrator or cold weld, is opened from the welding defect by applying tensile strain, leading to fracture. In order to apply tensile strain to the welded portion of the ERW pipe in the pipe making line, sufficient tensile strain can be applied to the welded portion by subjecting the welded portion to compression flattening from a direction of 90 degrees. Thus, as a result of investigating the relationship between the welding defect rate and the flattening rate of the stainless steel ERW pipe, the relationship between the welding defect rate and the flattening rate was able to be clarified. The welding defect rate is expressed by the following equation (1), where s is the area of the cold weld area, which is the halftone dot area shown in FIG. 2, and S is the area of the butted portion (thickness t × length L). ). Weld defect rate = (s / S) × 100 (%) (1) The flattening rate is shown in FIG. 3 (a). the outer diameter D 1 of the sewing tube, with an outer diameter D 2 of the short diameter side of the stainless steel seam welded pipe after giving a flat distortions as shown in FIG. 3 (b) represented by the following formula (2) You. Flatness = (D 1 −D 2 ) / D 1 × 100 (%) (2) The investigation was conducted in the following manner. First, flat strain based on a force directed toward the center in the radial direction across the stainless steel ERW pipe is gradually applied to each of a large number of stainless steel ERW pipes serving as samples at 90 degrees to the left and right from the welded portion. This is continued until a crack in the weld can be visually confirmed. The flattening rate defined by the equation (2) at the time when the crack occurs in the welded portion in this way is recorded. Thereafter, the sample is completely crushed, the weld is opened, and the sample is observed with a microscope to determine the weld defect rate defined by the equation (1). FIG. 4 shows the relationship between the welding defect rate and the flattening rate obtained by the above-mentioned investigation. From the results shown in the figure, it can be seen that there is a sample in which cracks in the welded portion cannot be visually observed until the flattening ratio reaches 30% even if the welding defect ratio is 2 to 3% (see the sample in FIG. 4). That is, if the flatness is 25%, the weld may not crack even if there is a welding defect. Conversely, it was confirmed that if a flattening rate of 30% or more was given, cracks were generated in all the welded parts containing welding defects. Meanwhile, J
In IS standard, flattening rate is 5 regardless of welding defect rate.
Up to 7% requires no cracking. Therefore, when a flattening rate of 30% to 60% is applied and no crack is detected, it can be determined that the product is practically free from welding defects. The configuration of the present invention based on such knowledge has the following features. 1) In the production line of the high-frequency welded steel pipe, by applying a force toward the center in the radial direction across the high-frequency welded steel pipe at a position 90 degrees to the left and right from the welded portion of the high-frequency welded steel pipe, 30% flatness
A flattening strain of about 60% is given, and thereafter, the circle is returned to a perfect circle by a straightening roll, and cracks in the welded portion are detected by eddy current testing or ultrasonic testing. 2) In a high-frequency welded steel pipe manufacturing apparatus for forming a steel sheet unwound from an uncoiler into a tube, welding the butt portion by high-frequency welding, and then cooling to obtain a high-frequency welded steel pipe, welding the cooled high-frequency welded steel pipe to the steel pipe A strain applying means for applying a flattening rate of 30% to 60% to the high-frequency welded steel pipe by applying a force toward the center in the radial direction across the high-frequency welded steel pipe at a position 90 degrees to the left and right from the portion; A straightening means for returning the strained high-frequency welded steel pipe to an original perfect circle, and an inspection means for detecting a crack in a welded portion of the high-frequency welded steel pipe returned to a perfect circle. In ferritic stainless steel, it is necessary to consider the brittle transition temperature of the weld, and it is necessary to control the temperature at which flat strain is applied. In order to clarify this point, a notch was mechanically formed in a sound weld, that is, a weld that did not cause cracks in the flat test as described above, and the sample having such a weld was subjected to various temperatures in a constant temperature chamber. The sample was held, and a Charby impact test was performed on each sample in this state. The result is shown in FIG. As shown in the figure,
It was found that when the temperature was 110 ° C. or higher, cracking did not progress unless a large impact was always applied. That is, if the temperature is 11
At 0 ° C. or higher, it shows ductility even if it contains welding defects (11
(There is a brittle transition temperature near 0 ° C.), and it has become clear that it is necessary to control the temperature of the welded portion to 110 ° C. or less when imparting flat strain in-line. Another configuration of the present invention based on such knowledge has the following features. 3) In the method for inspecting a high-frequency welded steel pipe described in 1) above, when the high-frequency welded steel pipe is ferritic stainless steel, the high-frequency welded steel pipe is heated to 110 ° C.
After performing temperature control as follows, flat strain is applied to the high-frequency welded pipe. 4) In the apparatus for manufacturing a high-frequency welded steel pipe of the above 2), the cooling means for controlling the temperature of the high-frequency welded steel pipe to be supplied to the strain applying means and cooling it so that the temperature becomes 110 ° C. or less is provided by the strain applying means. That it was arranged in the previous stage. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an apparatus for manufacturing a high-frequency welded steel pipe according to an embodiment of the present invention. Although the device according to the present embodiment will be described in the case of a stainless steel ERW pipe,
It is not limited to this. Generally, the present invention can be applied as an electric resistance welded tube manufacturing apparatus. As shown in FIG.
A stainless steel having an uncoiler 1, a forming roll 2, a high frequency welding machine 3, a cooling device 4, a flat roll 5, a straightening roll 6, an ultrasonic flaw detector 7, a traveling cutter 8 and a runner out table 9; A steel plate is formed by a forming roll 2 into a tubular member, and then the butted portion is high-frequency welded by a high-frequency welding machine 3 to form a stainless steel welded tube. The cooling device 4 cools the stainless steel ERW pipe immediately after the high-frequency welding. In this embodiment, the cooling is performed so that the temperature of the stainless steel ERW pipe at the outlet of the cooling device 4 becomes 110 ° C. or less. The temperature at this time may be any number as long as it is 110 ° C. or less, but considering the cooling efficiency and the brittle transition temperature together, a temperature in the vicinity of 110 ° C. or less is suitable. The flat roll 5, which is a means for imparting distortion, particularly extracts and enlarges this portion, as shown in FIG.
a, a cooled stainless ERW pipe is passed between opposing oval rolls 5c, 5d formed to be rotatable about 5b, and the stainless steel ERW pipe is sandwiched at 90 degrees to the left and right from the welded portion. By applying a force toward the center, a flat strain having a flat rate of 30% is applied to the stainless steel ERW pipe. In the present embodiment, the predetermined distortion is applied in two stages, but there is no particular limitation on the number of stages. The straightening roll 6 is used to return the stainless steel electric resistance welded tube having the flat strain to its original shape and to form it into a perfect circle. The ultrasonic flaw detector 7 is an inspection means for detecting a crack in the welded portion of the stainless steel ERW pipe that has been returned to a perfect circle. This may of course be an eddy current flaw detector. The stainless steel ERW pipe having undergone a predetermined inspection by the ultrasonic flaw detector 7 is cut into a predetermined size by the traveling cutter 8 and is carried into the runner out table 9. The runner out table 9 sorts non-defective and non-defective stainless steel ERW pipes based on the results of the inspection by the ultrasonic flaw detector 7. FIG. 3 is a characteristic diagram showing the results of a test for confirming the effect of the present embodiment. In FIG. 3, the plot points indicated by black circles are obtained by examining the relationship between the flaw detection value of the ultrasonic flaw detector 7 and the welding defect rate when a predetermined in-line flat strain is applied according to the present embodiment. In the same figure, the plotted points of white circles are the same as the other conditions, and are obtained by examining the relationship between the flaw detection value of the ultrasonic flaw detector 7 and the welding defect rate when no in-line flat strain is applied. In this test, the flaw detection value was recorded in each case, and then each stainless steel ERW tube as a sample was completely crushed, and the weld was opened and observed with a microscope to obtain a weld defined by the above equation (1). The defect rate is obtained and plotted in correspondence with the flaw detection value. In this case, a flaw detection value of 80% indicates that 80% of the emitted ultrasonic wave has been transmitted and received by the receiving unit, and it can be determined that the ultrasonic wave is non-defective. On the other hand, if the flaw detection value is 40% or less, it is determined to be defective. According to this standard, when the in-line flat strain is not applied, the flaw detection value may be 80% (good product) even if the welding defect rate is about 15% (see the sample), and the quality of the welded portion is 100%. While it cannot be guaranteed, when a predetermined in-line flat strain is applied as in this embodiment, the flaw detection value is about 20% (defective product) even if the welding defect rate is several% (see the sample), and 100% of the welded portion It can be seen that the quality assurance can be achieved. In some cases, even when no in-line flat distortion is applied, the flaw detection value is plotted in a small area such as a sample, that is, in a region where it can be determined to be defective. It is considered that cracking occurred in the welded portion due to the correction strain sometimes given. There is no problem when it is determined to be defective as described above, but there is a problem when it is not possible to detect a defective product by ultrasonic flaw detection despite the presence of a welding defect such as a sample. . This is because the accuracy of quality assurance is inferior. As described above in detail with the embodiments, according to the present invention, the quality of the welded portion can be completely detected in-line during the production of the ERW pipe, and the ERW pipe can be detected. A complete quality assurance can be made.
【図面の簡単な説明】
【図１】本発明の実施の形態に係る高周波溶接鋼管の製
造装置を示す概略構成図
【図２】図１の偏平ロール５の部分を抽出・拡大して示
す構成図。
【図３】本発明の実施の形態の効果を確認するための試
験の結果を示す特性図。
【図４】溶接欠陥率の定義を説明するための説明図。
【図５】偏平率の定義を説明するための説明図。
【図６】溶接欠陥率と偏平率との関係を示す特性図。
【図７】フェライト系ステンレス鋼の溶接部の脆性遷移
温度を示す特性図。
【符号の説明】
１ アンコイラー
２ 成形ロール
３ 高周波溶接機
４ クーリング装置
５ 偏平ロール
６ 矯正ロール
７ 超音波探傷装置BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a high-frequency welded steel pipe manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a configuration in which a portion of a flat roll 5 in FIG. 1 is extracted and enlarged. FIG. FIG. 3 is a characteristic diagram showing results of a test for confirming effects of the embodiment of the present invention. FIG. 4 is an explanatory diagram for explaining a definition of a welding defect rate. FIG. 5 is an explanatory diagram for explaining the definition of the flattening rate. FIG. 6 is a characteristic diagram showing a relationship between a welding defect rate and a flattening rate. FIG. 7 is a characteristic diagram showing a brittle transition temperature of a weld portion of a ferritic stainless steel. [Description of Signs] 1 Uncoiler 2 Forming roll 3 High frequency welding machine 4 Cooling device 5 Flat roll 6 Straightening roll 7 Ultrasonic flaw detector
───────────────────────────────────────────────────── フロントページの続き (72)発明者 梅花 賢一郎 神奈川県相模原市大山町１番30号 日本金 属工業株式会社相模原製造所内 (72)発明者 一戸 崇雄 神奈川県相模原市大山町１番30号 日本金 属工業株式会社相模原製造所内 (72)発明者 西野 正保 大阪府松原市丹南１丁目410番地 日金工 鋼管株式会社内 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenichiro Umehana 1-30 Oyamacho, Sagamihara City, Kanagawa Prefecture Sagamihara Factory (72) Inventor Takao Ichinohe 1-30 Oyamacho, Sagamihara City, Kanagawa Prefecture Sagamihara Factory (72) Inventor Masaho Nishino 1 410 Tannan, Matsubara-shi, Osaka Nichikinko Inside Steel Pipe Co., Ltd.
Claims (1)
て、 高周波溶接鋼管の溶接部から左右に９０度の位置でこの
高周波溶接鋼管を挟んで径方向中心に向かう力を付与す
ることによりこの高周波溶接鋼管に偏平率３０％乃至６
０％の偏平歪みを与え、その後矯正ロールにより真円に
戻し、渦流探傷若しくは超音波探傷により溶接部の割れ
を検出することを特徴とする高周波溶接鋼管の検査方
法。 【請求項２】 アンコイラーから巻き戻した鋼板を管状
に成形するとともに突合せ部を高周波溶接し、その後冷
却することにより高周波溶接鋼管を得る高周波溶接鋼管
の製造装置において、 冷却した高周波溶接鋼管にその溶接部から左右に９０度
の位置でこの高周波溶接鋼管を挟んで径方向中心に向か
う力を付与することによりこの高周波溶接鋼管に偏平率
３０％乃至６０％の偏平歪みを与える歪付与手段と、偏
平歪みを付与した高周波溶接鋼管を元の真円に戻す矯正
手段と、真円に戻した高周波溶接鋼管の溶接部の割れを
検出する検査手段とを有することを特徴とする高周波溶
接鋼管の製造装置。 【請求項３】 〔請求項１〕の高周波溶接鋼管の検査方
法において、 高周波溶接鋼管がフェライト系ステンレス鋼である場合
において、この高周波溶接鋼管が１１０℃以下になるよ
うに温度制御をした後、高周波溶接鋼管に偏平歪みを付
与するようにしたことを特徴とする高周波溶接鋼管の検
査方法。 【請求項４】 〔請求項２〕の高周波溶接鋼管の製造装
置において、 歪付与手段に供給する高周波溶接鋼管の温度制御を行い
その温度が１１０℃以下になるように冷却する冷却手段
を歪付与手段の前段に配設したことを特徴とする高周波
溶接鋼管の製造装置。Claims: 1. In a manufacturing line of a high-frequency welded steel pipe, a force directed toward the center in the radial direction with the high-frequency welded steel pipe sandwiched between the welded portions of the high-frequency welded steel pipe at 90 degrees to the left and right. Therefore, the flatness of this high-frequency welded steel pipe is 30% to 6%.
A method for inspecting a high-frequency welded steel pipe, wherein a flat strain of 0% is given, and thereafter, the circle is returned to a perfect circle by a straightening roll, and a crack in a welded portion is detected by eddy current testing or ultrasonic testing. 2. A high-frequency welded steel pipe manufacturing apparatus for forming a steel sheet unwound from an uncoiler into a tubular shape, welding the butt portion by high-frequency welding, and then cooling to obtain a high-frequency welded steel pipe. A strain applying means for applying a force toward the center in the radial direction across the high-frequency welded steel pipe at a position 90 degrees to the left and right from the portion to apply a flat strain of 30% to 60% to the high-frequency welded steel pipe; An apparatus for manufacturing a high-frequency welded steel pipe, comprising: a straightening means for returning a strained high-frequency welded steel pipe to an original perfect circle; and an inspection means for detecting a crack in a welded portion of the high-frequency welded steel pipe returned to a perfect circle. . 3. The method for inspecting a high-frequency welded steel pipe according to claim 1, wherein, when the high-frequency welded steel pipe is ferritic stainless steel, the temperature of the high-frequency welded steel pipe is controlled to 110 ° C. or less, An inspection method for a high-frequency welded steel pipe, wherein a flat strain is applied to the high-frequency welded steel pipe. 4. The apparatus for manufacturing a high-frequency welded steel pipe according to claim 2, wherein the cooling means for controlling the temperature of the high-frequency welded steel pipe to be supplied to the strain applying means and cooling it so that the temperature becomes 110 ° C. or less is provided. An apparatus for producing a high-frequency welded steel pipe, which is provided before the means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8311569A JP2905157B2 (en) | 1996-11-22 | 1996-11-22 | Inspection method of high frequency welded steel pipe and its manufacturing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8311569A JP2905157B2 (en) | 1996-11-22 | 1996-11-22 | Inspection method of high frequency welded steel pipe and its manufacturing apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10153581A true JPH10153581A (en) | 1998-06-09 |
| JP2905157B2 JP2905157B2 (en) | 1999-06-14 |
Family
ID=18018818
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8311569A Expired - Lifetime JP2905157B2 (en) | 1996-11-22 | 1996-11-22 | Inspection method of high frequency welded steel pipe and its manufacturing apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2905157B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000176543A (en) * | 1998-12-09 | 2000-06-27 | Kawasaki Steel Corp | Detection and production of steel plate, and treating equipment for hot-rolled steel plate and producing equipment for cold-rolled steel plate |
| JP2009019887A (en) * | 2007-07-10 | 2009-01-29 | Nippon Steel Corp | Method and device for inspecting weld zone defect of electric resistance welded steel pipe |
| JP2009018315A (en) * | 2007-07-10 | 2009-01-29 | Nippon Steel Corp | Method and apparatus for inspecting defect in weld zone of electric resistance welded tube |
| CN100458436C (en) * | 2007-02-14 | 2009-02-04 | 沈阳银捷机械装备制造有限责任公司 | Multifunction electromagnetic flaw detection device |
| CN103105431A (en) * | 2013-01-15 | 2013-05-15 | 沈玉琴 | Eddy current high/low-frequency compound detection equipment for seamless steel tubes |
| CN103278559A (en) * | 2013-04-25 | 2013-09-04 | 宁波金特信钢铁科技有限公司 | Eddy current detecting device of seamless steel tubes |
| CN103357697A (en) * | 2013-08-01 | 2013-10-23 | 山东胜利钢管有限公司 | Manufacturing technology of longitudinal submerged arc welded pipe |
| JP2015085354A (en) * | 2013-10-31 | 2015-05-07 | Ｊｆｅスチール株式会社 | Manufacturing method of electric resistance welded steel pipe excellent in characteristics of welded part |
| CN105057932A (en) * | 2015-08-13 | 2015-11-18 | 山东水泊焊割设备制造有限公司 | Opening positioning device of opening plate splicing machine |
| CN108645909A (en) * | 2018-07-24 | 2018-10-12 | 湖州新兴汽车部件有限公司 | A kind of plate rolling tube machine flaw detection processing system |
-
1996
- 1996-11-22 JP JP8311569A patent/JP2905157B2/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000176543A (en) * | 1998-12-09 | 2000-06-27 | Kawasaki Steel Corp | Detection and production of steel plate, and treating equipment for hot-rolled steel plate and producing equipment for cold-rolled steel plate |
| CN100458436C (en) * | 2007-02-14 | 2009-02-04 | 沈阳银捷机械装备制造有限责任公司 | Multifunction electromagnetic flaw detection device |
| JP2009019887A (en) * | 2007-07-10 | 2009-01-29 | Nippon Steel Corp | Method and device for inspecting weld zone defect of electric resistance welded steel pipe |
| JP2009018315A (en) * | 2007-07-10 | 2009-01-29 | Nippon Steel Corp | Method and apparatus for inspecting defect in weld zone of electric resistance welded tube |
| CN103105431A (en) * | 2013-01-15 | 2013-05-15 | 沈玉琴 | Eddy current high/low-frequency compound detection equipment for seamless steel tubes |
| CN103278559A (en) * | 2013-04-25 | 2013-09-04 | 宁波金特信钢铁科技有限公司 | Eddy current detecting device of seamless steel tubes |
| CN103357697A (en) * | 2013-08-01 | 2013-10-23 | 山东胜利钢管有限公司 | Manufacturing technology of longitudinal submerged arc welded pipe |
| JP2015085354A (en) * | 2013-10-31 | 2015-05-07 | Ｊｆｅスチール株式会社 | Manufacturing method of electric resistance welded steel pipe excellent in characteristics of welded part |
| CN105057932A (en) * | 2015-08-13 | 2015-11-18 | 山东水泊焊割设备制造有限公司 | Opening positioning device of opening plate splicing machine |
| CN108645909A (en) * | 2018-07-24 | 2018-10-12 | 湖州新兴汽车部件有限公司 | A kind of plate rolling tube machine flaw detection processing system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2905157B2 (en) | 1999-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2905157B2 (en) | Inspection method of high frequency welded steel pipe and its manufacturing apparatus | |
| CN105842034A (en) | Crack defect test piece manufacturing method | |
| US4083223A (en) | Nondestructive inspection method for spot-welded joints | |
| CN108375581B (en) | Double-beam laser welding process defect control method based on acousto-optic signal monitoring | |
| JP5909873B2 (en) | Weld defect detection system, method for manufacturing ERW steel pipe, and method for manufacturing welded product | |
| KR20130089353A (en) | Spot welding machine able to evaluate spot welding strength | |
| JP5909874B2 (en) | Welding defect detection system for ERW pipe and method for manufacturing ERW pipe | |
| JP3314849B2 (en) | Standard specimen for non-destructive inspection and its manufacturing method | |
| JP2002071649A (en) | Welding monitoring method | |
| JP5082746B2 (en) | Manufacturing equipment and manufacturing method of square steel pipe | |
| JP2541078B2 (en) | ERW pipe defect discrimination method | |
| JP4210560B2 (en) | Laser welding monitoring method and laser welding monitoring apparatus | |
| US5466910A (en) | Method of testing weld seams using an eddy-current technique | |
| JP5909870B2 (en) | WELDING DEFECT DETECTING METHOD, ERW TUBE MANUFACTURING METHOD, AND WELDED PRODUCT MANUFACTURING METHOD | |
| Addamani et al. | Weld Bead Performance Assessment of P-GMAW Using Acoustic Emission (AE) Signals Through NDT Methods for MS ASTM A 106 B Grade Material | |
| JP5258218B2 (en) | Inspection method for weld defects in ERW pipe | |
| JPS60205356A (en) | Ultrasonic flaw detecting method of steel tube weld zone | |
| SU1746248A1 (en) | Method of estimating quality of butt joints of polyethylene tubes | |
| JP5797375B2 (en) | ERW steel pipe manufacturing method | |
| Chertov et al. | Determination of resistance spot weld quality in real time using reflected acoustic waves. Comparison with through-transmission mode | |
| JP2009019887A (en) | Method and device for inspecting weld zone defect of electric resistance welded steel pipe | |
| Zhao et al. | Research for ultrasonic fast-identification of the stick-weld defect | |
| JP2022169938A (en) | Method of evaluating butt-welded part of steel pipe | |
| JPS63249050A (en) | Non-destructive inspection for electric resistance welded pipe at time of manufacturing | |
| CN114378542A (en) | Method for manufacturing standard test block for nondestructive testing of crack defects |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19990223 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090326 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100326 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110326 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110326 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120326 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130326 Year of fee payment: 14 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140326 Year of fee payment: 15 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |