JPH026746A - Method for estimating mechanical strength of thick steel sheet - Google Patents
Method for estimating mechanical strength of thick steel sheetInfo
- Publication number
- JPH026746A JPH026746A JP63154925A JP15492588A JPH026746A JP H026746 A JPH026746 A JP H026746A JP 63154925 A JP63154925 A JP 63154925A JP 15492588 A JP15492588 A JP 15492588A JP H026746 A JPH026746 A JP H026746A
- Authority
- JP
- Japan
- Prior art keywords
- thick steel
- mechanical strength
- steel plate
- transverse
- ultrasonic
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 69
- 239000010959 steel Substances 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims description 19
- 238000005096 rolling process Methods 0.000 claims abstract description 9
- 238000009864 tensile test Methods 0.000 claims description 8
- 238000009863 impact test Methods 0.000 claims description 6
- 230000010287 polarization Effects 0.000 abstract description 4
- 230000001902 propagating effect Effects 0.000 abstract description 4
- 239000002344 surface layer Substances 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 43
- 238000012360 testing method Methods 0.000 description 13
- 238000005259 measurement Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 239000000523 sample Substances 0.000 description 9
- 238000002592 echocardiography Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】 〈産業上の利用分野〉 この発明は、厚鋼板の機械的強度の推定方法に関する。[Detailed description of the invention] <Industrial application field> The present invention relates to a method for estimating the mechanical strength of a thick steel plate.
〈従来の技術〉
鉄鋼業では、高品質の鋼材を効率よく、しかも歩留り高
く生産するために、製造工程中あるいは製造直後に、鋼
材の機械的強度を非破壊で迅速に評価できる方法の確立
が古くから強く要望されてきた。<Conventional technology> In the steel industry, in order to efficiently produce high-quality steel materials with high yields, it is necessary to establish a method that can quickly and non-destructively evaluate the mechanical strength of steel materials during or immediately after the manufacturing process. It has been strongly requested since ancient times.
鋼材での超音波の伝播速度を測定することによって、超
音波の伝播速度と関数関係にあるとされる鋼材の材料特
性値を連続、非破壊的に測定する方法については、既に
例えば特開昭５４−６８６８０号公報に提案されている
。A method for continuously and non-destructively measuring the material property values of steel materials, which are said to have a functional relationship with the ultrasonic propagation speed, by measuring the ultrasonic propagation speed in steel materials, has already been reported in Japanese Patent Laid-Open Publication No. This is proposed in Japanese Patent No. 54-68680.
この方法は、物体中に超音波を送受信して物体中の音速
を測定する方法において、２個の超音波受信器を被検体
の移送方向に一定間隔離して設置し、該一定間隔の範囲
内に超音波送信器を被検体の移送方向に可動なごとく設
置し、前記超音波送信器から超音波が送信されてから前
記各超音波受信器に受信されるまでの時間をそれぞれ計
測し、該２つの計測時間の差にもとづいて前記超音波送
信器を被検体の移送方向に移動させ、前記２つの計測時
間の差が零となった時の計測時間を用いて被検体中の音
速を算出することを特徴とする、物体中の音速を移送中
に測定する方法である。This method measures the speed of sound in an object by transmitting and receiving ultrasonic waves into the object. Two ultrasonic receivers are installed at a certain distance in the direction of transport of the object, and two An ultrasonic transmitter is installed so as to be movable in the direction of transport of the subject, and the time from when the ultrasonic wave is transmitted from the ultrasonic transmitter until it is received by each of the ultrasonic receivers is measured. The ultrasonic transmitter is moved in the transport direction of the subject based on the difference between the two measurement times, and the speed of sound in the subject is calculated using the measurement time when the difference between the two measurement times becomes zero. This is a method for measuring the speed of sound in an object while it is being transported.
〈発明が解決しようとする課題〉
しかしながら、上記特開昭５４−６８６８０号において
は、表面波の伝播速度と鋼材の材料特性値との間にどの
ような機構でどのような関数関係が生ずるのかについて
は一切言及しておらず、表面波の伝播速度を測定して鋼
材の材料特性値を測定できる根拠が不明確であり、仮に
、表面波の伝播速度と鋼材の材料特性値との間に関数関
係があったにしても、表面波は鋼材の表面のみを伝播す
るので、したがって鋼材の表面の状態はわかっても内部
の状態は必ずしも正確には測定できない欠点があって実
用上問題があった。<Problems to be Solved by the Invention> However, in the above-mentioned Japanese Patent Application Laid-Open No. 54-68680, what kind of mechanism causes what kind of functional relationship between the propagation velocity of surface waves and the material property values of steel materials? There is no mention of this at all, and the basis for measuring the material property values of steel materials by measuring the propagation velocity of surface waves is unclear. Even if there is a functional relationship, surface waves propagate only on the surface of the steel material, so even if the surface state of the steel material can be determined, the internal state cannot necessarily be accurately measured, which poses a practical problem. Ta.
この発明は、上記のような状況に鑑みてなされたもので
あって、その目的とするところは、■測定する超音波の
伝播速度として、鋼材の機械的性質と関係の深いものを
選択することによって根拠の明確な鋼材の機械的性質の
推定方法を提供する。This invention was made in view of the above-mentioned situation, and its purpose is to select a propagation velocity of ultrasonic waves to be measured that is closely related to the mechanical properties of steel materials. We provide a method for estimating the mechanical properties of steel materials with a clear basis.
■測定に用いる超音波は鋼材の板厚方向に伝わる波動と
して、表面層だけでない、鋼材全体の平均的な機械的性
質を推定できる方法を提供する。■The ultrasonic waves used for measurement are waves that propagate in the thickness direction of the steel material, providing a method for estimating the average mechanical properties of the entire steel material, not just the surface layer.
ことにある。There is a particular thing.
〈課題を解決するだめの手段〉
本発明は、超音波を利用して厚鋼板の機械的強度を推定
するに際し、超音波送受信子によって厚鋼板に横波を送
受信して、この厚鋼板の板厚方向に伝わる板圧延方向偏
波の横波の速度（ＶＬ ）と板圧延方向に直角な方向偏
波の横波の速度（ＶＣ）とから横波速度比（ｖＬ／ｖｃ
）を求め、この横波速度比と予め求められている横波
速度比と機械的強度との関係とを比較して、前記厚鋼板
の機械的強度を求めることを特徴とする厚１ｉｉＩ板の
機械的強度の推定方法である。<Means for Solving the Problem> The present invention, when estimating the mechanical strength of a thick steel plate using ultrasonic waves, transmits and receives transverse waves to and from the thick steel plate using an ultrasonic transmitter/receiver, and calculates the thickness of the thick steel plate. The shear wave velocity ratio (vL/vc) is calculated from the velocity of the transverse wave polarized in the plate rolling direction (VL) and the velocity of the transverse wave polarized in the direction perpendicular to the plate rolling direction (VC).
), and the mechanical strength of the thick steel plate is determined by comparing this shear wave velocity ratio with a predetermined relationship between the shear wave velocity ratio and the mechanical strength. This is a method for estimating strength.
〈作 用〉
厚鋼板の機械的強度等の材質は、−船釣に成分組成と組
織構造の２つの要素によって支配されている。<Function> The mechanical strength and other properties of thick steel plates are controlled by two factors: composition and structure.
このうち、成分組成は、製鋼におけるレードル分析によ
って詳細に知ることができるから、成分組成の機械的強
度等の材質への寄与は、特に新たに計測を行わなくても
推定することが可能であり、したがって、組織構造の機
械的強度等の材質への寄与を推定することによって、厚
鋼板の機械的強度を推定することが可能となる。さらに
、組織構造として、機械的強度に寄与するものは集合組
織であり、したがって、集合組織の生成の状況を計測す
ることにより、厚鋼板の機械的強度の推定が可能である
。Of these, the component composition can be known in detail through ladle analysis during steelmaking, so it is possible to estimate the contribution of the component composition to material properties such as mechanical strength without particularly performing new measurements. Therefore, it is possible to estimate the mechanical strength of a thick steel plate by estimating the contribution of the microstructure to the material properties such as mechanical strength. Furthermore, the texture contributes to mechanical strength, and therefore, by measuring the state of formation of texture, it is possible to estimate the mechanical strength of a thick steel plate.
ここで、集合組織とは、金属組織を形成している個々の
単結晶の特定の方向が材料の特定の方向に集合している
金属組織であって、個々の単結晶は、物理的性質３機械
的性質等の様々な性質が方向によって異なる異方性を有
しているから、集合組織を有する材料は材料全体として
みても各種の性質が異なり、異方性を示す。Here, the texture is a metal structure in which specific directions of individual single crystals forming the metal structure are aggregated in a specific direction of the material, and each single crystal has physical properties 3 Since various properties such as mechanical properties have anisotropy that differs depending on the direction, a material having a texture has various properties that differ even when viewed as a material as a whole and exhibits anisotropy.
厚鋼板の集合組織はＴ±αの２相域での圧延加工によっ
て生成されることが知られている。したがって、厚鋼板
に生成された集合組織による材料全体の異方性は、圧延
加工の対称性から考えて、材料全体が斜方晶系の単結晶
であるかのような異方性となる。It is known that the texture of thick steel plates is generated by rolling in the T±α two-phase region. Therefore, considering the symmetry of the rolling process, the anisotropy of the entire material due to the texture generated in the thick steel plate is as if the entire material were an orthorhombic single crystal.
集合組織の生成されていない通常の圧延鋼材での３次元
での応力とひずみの関係における弾性定数行列は２つの
独立した弾性定数Ｃ＋＋、Ｃ＋□によって記述され、下
記（１）式で表される。The elastic constant matrix in the three-dimensional relationship between stress and strain in normal rolled steel material without texture is described by two independent elastic constants C++ and C+□, and is expressed by the following equation (1). .
ここで、Ｃａ １””’ Ｃ＋
Ｉ２
これに対して、集合組織の生成されている厚鋼板での３
次元での応力とひずみの関係における弾性定数行列は、
前記したことから下記（２）式に示す９個の独立した弾
性定数によって記述される。Here, Ca 1""' C+ I2 On the other hand, 3 in thick steel plate where texture is generated
The elastic constant matrix in the stress-strain relationship in dimension is
From the above, it is described by nine independent elastic constants shown in equation (2) below.
これら（１）、 （２）式の２つの弾性定数行列を見比
べれば、（２）式における弾性定数のそれぞれの比ＣＩ
ｌ／Ｃａｌ Ｃ２２／Ｃ３３，Ｃ３３／Ｃ目、ＣＩ２
／Ｃｌ５Ｃ＋３／Ｃｚａ、Ｃ２３／ＣＩ２．Ｃ４４／Ｃ
５Ｓ、Ｃ５５／Ｃ６６＋ Ｃ６６／ Ｃ４４＋ は、
（１）式では１であり、したがって、これら弾性定数の
比が１から大きくずれている鋼板はど集合組織による弾
性的な異方性の程度が大きいと結論でき、これら弾性定
数の比をもって、異方性の程度すなわち、集合組織の生
成の程度を評価することができる。Comparing these two elastic constant matrices in equations (1) and (2), we can see that the respective ratio CI of elastic constants in equation (2)
l/Cal C22/C33, C33/Cth, CI2
/Cl5C+3/Cza, C23/CI2. C44/C
5S, C55/C66+ C66/C44+,
In Equation (1), it is 1. Therefore, it can be concluded that steel sheets whose ratio of these elastic constants deviates significantly from 1 have a large degree of elastic anisotropy due to the texture, and with the ratio of these elastic constants, The degree of anisotropy, that is, the degree of texture formation can be evaluated.
（２）式における９個の弾性定数は、縦波および横波の
伝播速度を測定することによって求めることが可能であ
るが、そのためには複雑な形状の試験片を切り出す必要
があって、容易に迅速には実施することができない。そ
こで、発明者は前記した弾性定数のそれぞれの比のうち
、測定が容易に実施でき、かつ大きな値となるものを検
討した結果、Ｃ４４／Ｃ５５が最も適当であり、かつ、
この比は、板厚方向に伝わる板圧延方向（以下、Ｌ方向
という）偏波の横波の速度ｖＬと、板厚方向に伝わる板
圧延方向に直角な方向（以下、Ｃ方向という）偏波の横
波の速度■。との比Ｖ＋、／Ｖｃ、すなわち横波速度比
と全く同等であることを見出した。The nine elastic constants in Equation (2) can be determined by measuring the propagation speed of longitudinal waves and transverse waves, but this requires cutting out a test piece with a complicated shape, which is not easy. It cannot be implemented quickly. Therefore, among the above-mentioned ratios of elastic constants, the inventors investigated ratios that can be easily measured and have large values, and found that C44/C55 is the most appropriate ratio, and
This ratio is the velocity vL of the transverse wave polarized in the plate rolling direction (hereinafter referred to as the L direction) transmitted in the plate thickness direction and the transverse wave polarized in the direction perpendicular to the plate rolling direction (hereinafter referred to as the C direction) transmitted in the plate thickness direction. Speed of transverse wave■. It has been found that the ratio V+, /Vc, that is, the ratio of transverse wave velocity, is completely equivalent to the transverse wave velocity ratio.
したがって、例えば超音波探触子などの超音波測定装置
を厚鋼板の表面に当てて横波速度比（ＶＬ／ＶＣ）を測
定することにより、各種の機械的強度を推定することが
可能である。Therefore, it is possible to estimate various mechanical strengths by applying an ultrasonic measurement device such as an ultrasonic probe to the surface of a thick steel plate and measuring the transverse wave velocity ratio (VL/VC).
機械的強度として、引張り試験における降伏応力（Ｙ、
）および引張り強さ（ＴＳ）、また、衝撃試験における
延性破面率および衝撃値のそれぞれと横波速度比（ｖＬ
／ｖｃ）との特性の一例を第４〜７図に示す。As mechanical strength, yield stress (Y,
) and tensile strength (TS), as well as the ductile fracture ratio and impact value in the impact test, and the shear wave velocity ratio (vL), respectively.
/vc) are shown in FIGS. 4-7.
これらの図から明らかなように、各種の材料試験におけ
る材料試験値と横波速度比とには、非常に明瞭な相関関
係が得られることがわかる。それ故、厚鋼板の主な鋼種
ごとに、材料試験値と横波速度比との関係を予め調査し
て求めておけば、横波速度比を計測することにより、材
料試験値を推定することができ、また、成分情報と横波
速度比の計測値を総合しても、材料試験値を推定するこ
とができる。As is clear from these figures, a very clear correlation can be obtained between material test values and shear wave velocity ratios in various material tests. Therefore, if the relationship between the material test value and shear wave velocity ratio is investigated and determined in advance for each major steel type of thick steel plate, the material test value can be estimated by measuring the shear wave velocity ratio. In addition, the material test value can be estimated by combining the component information and the measured value of the shear wave velocity ratio.
〈実施例〉
以下に、本発明の実施例について図面を参照して詳しく
説明する。<Examples> Examples of the present invention will be described in detail below with reference to the drawings.
〔実施例１〕
第１図は、本発明方法の実施に横波超音波探触子を用い
て静止した厚鋼板の横波速度比を測定する例を示すブロ
ック図である。[Example 1] FIG. 1 is a block diagram showing an example of measuring the shear wave velocity ratio of a stationary thick steel plate using a shear wave ultrasonic probe in carrying out the method of the present invention.
図に示すように、横波超音波探触子１は、被検材である
静止した厚鋼板２の表面に横波が透過可能な粘性の高い
媒質を介して押し当てられる。そして、電気パルス送信
器１１から送信される一定の繰り返し周波数を有する電
気パルスを受信して厚鋼板２の厚さ方向に横波超音波パ
ルスを送信する。As shown in the figure, a transverse wave ultrasonic probe 1 is pressed against the surface of a stationary thick steel plate 2, which is a material to be tested, via a highly viscous medium through which transverse waves can pass. Then, an electric pulse having a constant repetition frequency transmitted from the electric pulse transmitter 11 is received, and a transverse ultrasonic pulse is transmitted in the thickness direction of the thick steel plate 2.
この送信された横波超音波パルスは厚鋼板２のなかで多
重反射を繰り返すが、界面での反射率および透過率に応
じた振幅で横波超音波探触子１に受信され、再び電気信
号に変換されて受信増幅器１２に送られ、適当に増幅さ
れる。The transmitted transverse ultrasonic pulse undergoes multiple reflections within the thick steel plate 2, but is received by the transverse ultrasonic probe 1 with an amplitude corresponding to the reflectance and transmittance at the interface, and is converted into an electrical signal again. The received signal is then sent to a receiving amplifier 12 where it is appropriately amplified.
なお、横波超音波パルスは、超音波振動子の材料を適当
とすることにより、一定の方向に偏波させるようにする
。Note that the transverse ultrasonic pulse is polarized in a fixed direction by selecting a suitable material for the ultrasonic transducer.
受信増幅器１２で増幅された信号は、ゲート回路１３ａ
、１３ｂへ出力される。ゲート回路１３ａでは入力され
た信号から被検材３１の底面で１回反射したエコーＢ１
を、ゲート回路１３ｂでは入力された信号から厚鋼板２
の底面でｎ回反射したエコーＢ、。The signal amplified by the reception amplifier 12 is sent to the gate circuit 13a.
, 13b. In the gate circuit 13a, an echo B1 is reflected once from the bottom surface of the test material 31 from the input signal.
The gate circuit 13b detects the thick steel plate 2 from the input signal.
Echo B, reflected n times from the bottom of the .
をそれぞれ取り出して時間計測器１４の入力端子１４ａ
、１４ｂにそれぞれ出力する。are respectively taken out and connected to the input terminal 14a of the time measuring device 14.
, 14b, respectively.
時間計測器１４では、２つの入力端子１４ａ、１４ｂに
それぞれ加えられた信号の時間差を計測し、演算処理器
１５へ出力する。The time measuring device 14 measures the time difference between the signals applied to the two input terminals 14a and 14b, and outputs it to the arithmetic processor 15.
上記の過程は、横波超音波探触子１から送信される横波
超音波パルスの偏波方向が、Ｃ方向およびＬ方向の２つ
の場合について行われ、演算処理器１５においてそれぞ
れの場合での時間計測値が記録または記憶される。The above process is performed for two cases in which the polarization direction of the transverse ultrasound pulse transmitted from the transverse ultrasound probe 1 is the C direction and the L direction, and the processing unit 15 calculates the time in each case. Measured values are recorded or stored.
いま、横波超音波パルスがＬ方向に偏波している場合の
時間計測値をΔＬＬとし、横波超音波パルスがＣ方向に
偏波している場合の時間計測値をΔｔＣとすると、横波
速度比（ｖｔ ／ｖｃ ）は、下記（３）式によって求
められる。Now, if the time measurement value when the transverse ultrasonic pulse is polarized in the L direction is ΔLL, and the time measurement value when the transverse ultrasonic pulse is polarized in the C direction is ΔtC, then the transverse wave velocity ratio is (vt /vc) is determined by the following equation (3).
ＶＬ／ＶＣ＝Δｔｃ／ΔｔＬ −−−−−、（３）
この（３）式で得られた横波速度比（ＶＬ／ＶＣ）は、
演算処理器１５に予め記録または記憶されている横波速
度比と各種の材料試験値との対応関係から、各種の機械
的強度の推定値が表示器１６に表示され、記録媒体１７
に記録されるほか、プリンタなどの出力装置１８に出力
される。VL/VC=Δtc/ΔtL ------, (3)
The shear wave velocity ratio (VL/VC) obtained from this equation (3) is:
Based on the correspondence between the transverse wave velocity ratio recorded or stored in advance in the arithmetic processor 15 and various material test values, various estimated values of mechanical strength are displayed on the display 16, and the estimated values are displayed on the recording medium 17.
In addition to being recorded on the computer, the information is also output to an output device 18 such as a printer.
なお、横波超音波パルスの伝播時間の測定において、被
検材の異方性の関係から単一のモードの横波が送受信さ
れるのは横波超音波パルスの偏波方向が、ＬまたはＣ方
間に合った場合のみであること、かつ、板厚方向に伝わ
るし方向偏波の横波速度ｖＬは、板厚方向に伝わるＣ方
向偏波の横波の横波速度ｖｃよりも大きいことの物理的
性質を利用して、横波超音波探触子１を厚鋼板２に対し
て回転させ、単一のモードの横波が送受信される２つの
場合について、前記した伝播時間の測定を行い、伝播時
間測定値の大きい方の値をΔ１゜伝播時間測定値の小さ
い方の値をΔｔ２としたとき、下記（４）式によって横
波速度比を求めるようにしてもよい。In measuring the propagation time of a transverse ultrasonic pulse, due to the anisotropy of the material being tested, a single mode of transverse wave is transmitted and received only when the polarization direction of the transverse ultrasonic pulse is aligned with the L or C direction. This method uses the physical property that the shear wave velocity vL of the C-direction polarized wave propagating in the plate thickness direction is larger than the shear wave velocity vc of the C-polarized shear wave propagating in the plate thickness direction. Then, the transverse wave ultrasonic probe 1 is rotated with respect to the thick steel plate 2, and the propagation time is measured as described above for the two cases in which a single mode transverse wave is transmitted and received. The transverse wave velocity ratio may be determined by the following equation (4), where the value of Δ1° is the smaller value of the propagation time measurement values Δt2.
ＶＬ／Ｖ、−Δ１＋／Δｔ２ −−−−−−−−（４
）上記のように構成した横波速度比測定装置を用いて、
鋼種が５０ｋｇｆ／−クラス鋼（引張り強さが５０ｋｇ
ｆ／−以上の鋼）で板厚が１２〜３４１ｗＩＩ＋の厚鋼
板の各種材料試験値を測定した。測定に用いた横波超音
波探触子にて送受信される横波超音波パルスの周波数は
５ＭＨｚである。VL/V, −Δ1+/Δt2 −−−−−−−(4
) Using the transverse wave velocity ratio measuring device configured as above,
Steel type is 50kgf/- class steel (tensile strength is 50kg
Various material test values were measured for thick steel plates with plate thicknesses of 12 to 341 wII+ (steel with f/- or more). The frequency of transverse ultrasonic pulses transmitted and received by the transverse ultrasonic probe used in the measurement is 5 MHz.
測定した結果を、第１表に示した。The measured results are shown in Table 1.
なお、従来法と比較するために、表面波速度を測定した
結果も同表に併せて示し、さらに、材料試験値の中から
降伏応力および引張り試験値との関係を第８，９図に示
した。In addition, in order to compare with the conventional method, the results of surface wave velocity measurements are also shown in the same table, and the relationship between yield stress and tensile test values among the material test values is shown in Figures 8 and 9. Ta.
これらの第１表、第８図、および第９図から明らかなよ
うに、本発明法による測定値はいずれも引張り試験や衝
撃試験によって得られた値とよく一致しており、従来法
よりもはるかに精度が高いことがわかる。なお、従来法
において材料試験値と表面波速度との関係に大きなばら
つきが存在するのは、材料の表面層のみを伝播する表面
波の速度では、材料全体の材質特性を評価することが難
しいことによると推量される。As is clear from Table 1, Figure 8, and Figure 9, the measured values obtained by the method of the present invention all agree well with the values obtained by the tensile test and impact test, and are better than those obtained by the conventional method. It can be seen that the accuracy is much higher. The reason for the large variations in the relationship between material test values and surface wave velocity in conventional methods is that it is difficult to evaluate the material properties of the entire material using the surface wave velocity that propagates only through the surface layer of the material. It is estimated that.
〔実施例２〕
第２図は、本発明方法の実施に電磁式横波超音波送受信
装置を用いて搬送される厚鋼板の横波速度比を測定する
例を示すブロック図である。[Embodiment 2] FIG. 2 is a block diagram showing an example of measuring the transverse wave velocity ratio of a thick steel plate being conveyed using an electromagnetic transverse wave ultrasonic transmitter/receiver in carrying out the method of the present invention.
図に示すように、被検材である厚鋼板２は、搬送ローラ
３によって矢示方向に搬送されるのであるが、その表面
に、電磁式横波超音波送受信子２１が適当なエアギャッ
プをおいて図示しない支持手段によって配置される。As shown in the figure, a thick steel plate 2, which is the material to be inspected, is conveyed in the direction of the arrow by conveyance rollers 3, and an electromagnetic transverse wave ultrasonic transmitter/receiver 21 creates an appropriate air gap on its surface. It is arranged by supporting means (not shown).
この電磁式横波超音波送受信子（以下、単に送受信子と
いう）２１は、磁界発生用コイルと鉄心および超音波発
生検出用コイルで構成される。そして、磁界発生用電源
２２から送受信子２１の磁界発生用コイルに電流が通電
されると、厚鋼板２の表面近傍に磁界が発生する。一方
、送受信子２１の超音波発生検出用コイルに高周波パル
ス信号源２３からパルス状の電流が流れて、厚鋼板２の
表面近傍に電磁誘導によって渦電流が励起され、この渦
電流と前記磁界との相互作用の結果、フレミングの法則
によって運動力が生じ、厚鋼板２の板厚方向に横波超音
波が送信される。この横波超音波の送信において、送受
信子２１を構成する磁界発生用コイル、鉄心、および超
音波発生検出用コイルの形状および配置を適当とするこ
とにより、放射状に偏波した横波超音波を送信すること
ができる。送信された横波超音波は厚鋼板２のなかで多
重反射を繰り返すが、厚鋼板２の送受信子２１を設置し
た側の表面に達した時、送信とは全く逆の過程によって
、超音波発生検出用コイルに受信され、このコイルに接
続された受信増幅器２４によって増幅される。This electromagnetic transverse wave ultrasonic transceiver (hereinafter simply referred to as a transceiver) 21 is composed of a magnetic field generation coil, an iron core, and an ultrasonic generation detection coil. When a current is applied from the magnetic field generating power supply 22 to the magnetic field generating coil of the transceiver 21, a magnetic field is generated near the surface of the thick steel plate 2. On the other hand, a pulsed current flows from the high-frequency pulse signal source 23 into the ultrasonic generation/detection coil of the transmitter/receiver 21, and an eddy current is excited near the surface of the thick steel plate 2 by electromagnetic induction. As a result of the interaction, a kinetic force is generated according to Fleming's law, and a transverse ultrasonic wave is transmitted in the thickness direction of the thick steel plate 2. In transmitting transverse ultrasonic waves, radially polarized transverse ultrasonic waves are transmitted by appropriately arranging the shape and arrangement of the magnetic field generating coil, iron core, and ultrasonic generation detection coil that constitute the transceiver 21. be able to. The transmitted transverse ultrasonic wave repeats multiple reflections within the thick steel plate 2, but when it reaches the surface of the thick steel plate 2 on the side where the transmitter/receiver 21 is installed, the ultrasonic wave generation is detected by a process completely opposite to that of transmission. The received signal is received by a receiving coil and amplified by a receiving amplifier 24 connected to this coil.
この受信増幅器２４によって増幅された横波超音波の信
号波形の一例を第３図に示す。この信号は、厚鋼板２の
異方性の関係から、速度ＶＬ （板厚方向に伝わるし
方向に偏波した横波の速度）のモードの横波と、速度Ｖ
、（板厚方向に伝わるＣ方向に偏波した横波の速度）の
モードの横波とが加え合わされたものとなっている。An example of the signal waveform of the transverse ultrasonic wave amplified by the receiving amplifier 24 is shown in FIG. Due to the anisotropy of the thick steel plate 2, this signal is composed of a transverse wave with a mode of velocity VL (velocity of a transverse wave transmitted in the thickness direction and polarized in the transverse direction) and a transverse wave with a mode of velocity V
, (velocity of the transverse wave polarized in the C direction propagating in the plate thickness direction) are added together.
この信号は、３個のゲート回路２５ａ、 ２５ｂ、 ２
５Ｃに出力され、ゲート回路２５ａでは前記２つのモー
ドの横波が厚鋼板２の底面で１回反射したエコー３１ａ
、３１ｂが取り出され、信号３３として時間計測器２６
の入力端子２６ａに出力される。また、ゲート回路２５
ｂでは、前記２つのモードの横波が厚鋼板２の底面で２
回反射したエコー３２ａ、３２ｂが取り出され、時間計
測器２６の入力端子２６ｂおよび時間計測器２７の入力
端子２７ａに信号３４として出力される。さらに、デー
１〜回路２５ｃでは、前記２つのモードの横波が厚鋼板
２の底面で２回反射したエコーのうち、速度Ｖ、のモー
ドの横波によるエコー３２ｂが取り出され、時間計測器
２７の入ツノ端子２７ｂに信号３５として出力される。This signal is transmitted to three gate circuits 25a, 25b, 2
5C, and in the gate circuit 25a, an echo 31a of the two modes of transverse waves reflected once on the bottom surface of the thick steel plate 2 is generated.
, 31b are taken out, and the time measuring device 26 is output as a signal 33.
It is output to the input terminal 26a of. In addition, the gate circuit 25
In b, the transverse waves of the two modes are 2 at the bottom of the thick steel plate 2.
The reflected echoes 32a and 32b are extracted and output as a signal 34 to the input terminal 26b of the time measuring device 26 and the input terminal 27a of the time measuring device 27. Further, in the circuit 25c from Day 1, among the echoes of the two modes of transverse waves reflected twice on the bottom surface of the thick steel plate 2, an echo 32b due to the transverse wave of the mode of velocity V is extracted and input to the time measuring device 27. It is output as a signal 35 to the horn terminal 27b.
時間計測器２６では、入力端子２６ａ、２６ｂに入力さ
れた信号の立上がりの時間差を計測して、演算処理器１
５に出力するが、この時間差の計測値ΔＬ１は、速度■
、のモードの横波の伝播時間をΔム１、速度■。のモー
ドの横波の伝播時間をΔむ。とじたとき、
Δｔ、−八ｔ へ （５）
となる。The time measuring device 26 measures the time difference between the rises of the signals input to the input terminals 26a and 26b, and
5, the measured value ΔL1 of this time difference is the speed ■
, the propagation time of the transverse wave in the mode is Δm1, and the velocity ■. The propagation time of the transverse wave of the mode is Δ. When closed, Δt, -8t (5)
becomes.
また、時間計測器２７では、入力端子２７ａ、２７ｂに
入力された信号の立上がりの時間差を計測して、演算処
理器１５に出力するが、この時間差の計測値ΔＬ２は、
Δｔｚ ＝２ （Δｔｃ−ΔｔＬ） （６）と
なる。Further, the time measuring device 27 measures the time difference between the rises of the signals input to the input terminals 27a and 27b, and outputs it to the arithmetic processing unit 15. The measured value ΔL2 of this time difference is Δtz = 2 (Δtc− ΔtL) (6).
演算処理器１５では入力された時間差の計測値から、横
波速度比（ＶＬ ／ｖｃ ）を
ＶＬ／ＶＣ−（（Δｔｚ／２）＋Δｔ、）／Δｔ。The arithmetic processor 15 calculates the transverse wave velocity ratio (VL/vc) as VL/VC-((Δtz/2)+Δt,)/Δt from the input measured value of the time difference.
によって求め、予め記録または記憶されている横波速度
比と各種の材料試験値との対応関係から、各種の機械的
強度の推定値が算出される。その結果は表示器１６に表
示され、記録媒体１７に記録されるほか、プリンタなど
の出力語！１Ｂに出力される。Estimated values of various mechanical strengths are calculated from the correspondence between the transverse wave velocity ratio obtained by and recorded or stored in advance and various material test values. The results are displayed on the display 16, recorded on the recording medium 17, and output to a printer, etc. Output to 1B.
このようにして、鋼板の搬送ライン上で横波速度比を計
測して、各種の機械的強度の値を推定することができる
。In this way, it is possible to measure the shear wave velocity ratio on the steel plate conveyance line and estimate various mechanical strength values.
上記のように構成した横波速度比測定装置を用いて、鋼
種が５０ｋｇｆ／−クラス鋼で板厚が８〜３２鴫の厚鋼
板の各種材料試験値を測定した。測定に用いた電磁式横
波超音波送受信子にて送受信される横波高周波パルスの
周波数は５ＭＩＩｚである。Using the transverse wave velocity ratio measuring device configured as described above, various material test values of thick steel plates of 50 kgf/- class steel and thicknesses of 8 to 32 mm were measured. The frequency of the transverse high-frequency pulse transmitted and received by the electromagnetic transverse ultrasonic transmitter/receiver used in the measurement is 5 MIIz.
測定した結果を、第２表に示した。The measured results are shown in Table 2.
この表から明らかなように、本発明法による測定値はい
ずれも引張り試験や衝撃試験によって得られた値とよく
一致していることがわかる。As is clear from this table, all the values measured by the method of the present invention are in good agreement with the values obtained by the tensile test and the impact test.
〈発明の効果〉
以上説明したように、この発明によれば、厚鋼板の機械
的強度を、製造工程中あるいは製造直後に、非破壊で迅
速に精度高く推定でき、この情報はすぐさま製造条件に
フィードバックして、高品質の鋼材を効率よく生産する
ことができるなど、その工業的な価値は絶大である。<Effects of the Invention> As explained above, according to the present invention, the mechanical strength of a thick steel plate can be estimated nondestructively, quickly, and with high accuracy during or immediately after manufacturing, and this information can be immediately applied to manufacturing conditions. Its industrial value is enormous, as it allows feedback to be used to efficiently produce high-quality steel materials.
第１図は、本発明方法の実施に横波超音波探触子を用い
て、静止した厚鋼板の横波速度比を測定する例を示すブ
ロック図、第２図は、本発明方法の実施に電磁式横波超
音波送受信子を用いて、搬送される厚鋼板の横波速度比
を測定する例を示すブロック図、第３図は、横波超音波
の信号波形の一例を示す特性図、第４図は、横波速度比
と引張り試験における降伏応力（ＹＰ ）との関係を示
す特性図、第５図は、横波速度比と引張り試験における
引張り強さ（Ｔ３）との関係を示す特性図、第６図は、
横波速度比と衝撃試験における延性破面率との関係を示
す特性図、第７図は、横波速度比と衝撃試験における衝
撃値との関係を示す特性図、第８図は、表面波速度と引
張り試験における降伏応力（ＹＰ ）との関係を示す特
性図、第９図は、表面波速度と引張り試験における引張
り強さ（Ｔ、）との関係を示す特性図である。
１・・・横波超音波探触子、 ２・・・厚鋼板３・・
・搬送ローラ。
１１・・・電気パルス送信器、１２・・・受信増幅器。
１３・・・ゲート回路、１４・・・時間計測器１５・・
・演算処理器、１６・・・表示器。
１７・・・記録媒体、１８・・・出力装置。
２１・・・電磁式横波超音波送受信子。
２２・・・磁界発生用電源。
２３・・・高周波パルス信号源、２４・・・受信増幅器
２５・・・ゲート回路、 ２６．２７・・・時間
計測器。
３Ｌ ３２・・・超音波エコー
３３、３４．３５・・・超音波エコーを含む電気信号。
特許出願人 川崎製鉄株式会社
第
図
第
図
時
間
（ＦＭ／ＪｆｔＭ）
１人ｑ望Ｙ）姻
（門／Ｊ均）
９↓
９％（、（、坐１１FIG. 1 is a block diagram showing an example of measuring the shear wave velocity ratio of a stationary thick steel plate using a shear wave ultrasonic probe in carrying out the method of the present invention, and FIG. A block diagram showing an example of measuring the shear wave velocity ratio of a thick steel plate being conveyed using a transverse wave ultrasonic transmitter/receiver, Fig. 3 is a characteristic diagram showing an example of the signal waveform of the shear wave ultrasonic wave, and Fig. 4 is a , a characteristic diagram showing the relationship between the shear wave velocity ratio and the yield stress (YP) in the tensile test, FIG. 5 is a characteristic diagram showing the relationship between the shear wave velocity ratio and the tensile strength (T3) in the tensile test, and FIG. teeth,
Figure 7 is a characteristic diagram showing the relationship between the shear wave velocity ratio and the ductile fracture ratio in the impact test. Figure 8 is a characteristic diagram showing the relationship between the shear wave velocity ratio and the impact value in the impact test. FIG. 9 is a characteristic diagram showing the relationship between the yield stress (YP) in the tensile test, and FIG. 9 is a characteristic diagram showing the relationship between the surface wave velocity and the tensile strength (T, ) in the tensile test. 1... Shear wave ultrasonic probe, 2... Thick steel plate 3...
・Transport roller. 11... Electric pulse transmitter, 12... Receiving amplifier. 13... Gate circuit, 14... Time measuring device 15...
- Arithmetic processing unit, 16...display unit. 17... Recording medium, 18... Output device. 21...Electromagnetic transverse wave ultrasonic transmitter/receiver. 22...Magnetic field generation power supply. 23...High frequency pulse signal source, 24...Reception amplifier 25...Gate circuit, 26.27...Time measuring device. 3L 32... Ultrasonic echoes 33, 34. 35... Electrical signals including ultrasonic echoes. Patent Applicant: Kawasaki Steel Co., Ltd. Figure Figure Time (FM/JftM) 1 person q Wang Y) Marriage (Mon/J Hitoshi) 9↓ 9% (, (, za 11
Claims (1)
際し、超音波送受信子によって厚鋼板に横波を送受信し
て、この厚鋼板の板厚方向に伝わる板圧延方向偏波の横
波の速度（Ｖ＿Ｌ）と板圧延方向に直角な方向偏波の横
波の速度（Ｖ＿Ｃ）とから横波速度比（Ｖ＿Ｌ／Ｖ＿Ｃ
）を求め、この横波速度比と予め求められている横波速
度比と機械的強度との関係とを比較して、前記厚鋼板の
機械的強度を求めることを特徴とする厚鋼板の機械的強
度の推定方法。 ２、前記機械的強度は、引張り試験における降伏応力と
引張り強さおよび衝撃試験における延性破面率と衝撃値
であることを特徴とする請求項１記載の厚鋼板の機械的
強度の推定方法。[Claims] 1. When estimating the mechanical strength of a thick steel plate using ultrasonic waves, transverse waves are sent and received to the thick steel plate by an ultrasonic transmitter/receiver, and the plate rolling is transmitted in the thickness direction of the thick steel plate. The shear wave speed ratio (V_L / V_C
), and the mechanical strength of the thick steel plate is determined by comparing this shear wave velocity ratio with a predetermined relationship between the shear wave velocity ratio and the mechanical strength. estimation method. 2. The method for estimating the mechanical strength of a thick steel plate according to claim 1, wherein the mechanical strength is the yield stress and tensile strength in a tensile test, and the ductile fracture ratio and impact value in an impact test.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63154925A JPH026746A (en) | 1988-06-24 | 1988-06-24 | Method for estimating mechanical strength of thick steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63154925A JPH026746A (en) | 1988-06-24 | 1988-06-24 | Method for estimating mechanical strength of thick steel sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH026746A true JPH026746A (en) | 1990-01-10 |
Family
ID=15594947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63154925A Pending JPH026746A (en) | 1988-06-24 | 1988-06-24 | Method for estimating mechanical strength of thick steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH026746A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994000755A1 (en) * | 1992-06-25 | 1994-01-06 | Hitachi Construction Machinery Co., Ltd. | Method and apparatus for ultrasonic measurement |
| EP0737861A1 (en) * | 1995-04-03 | 1996-10-16 | MANNESMANN Aktiengesellschaft | Method and apparatus for non-destructive determination of properties of a metal component |
| JP2003028842A (en) * | 2001-07-13 | 2003-01-29 | Taisei Corp | Method and apparatus for measurement of strength of concrete surface layer part |
-
1988
- 1988-06-24 JP JP63154925A patent/JPH026746A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994000755A1 (en) * | 1992-06-25 | 1994-01-06 | Hitachi Construction Machinery Co., Ltd. | Method and apparatus for ultrasonic measurement |
| EP0737861A1 (en) * | 1995-04-03 | 1996-10-16 | MANNESMANN Aktiengesellschaft | Method and apparatus for non-destructive determination of properties of a metal component |
| JP2003028842A (en) * | 2001-07-13 | 2003-01-29 | Taisei Corp | Method and apparatus for measurement of strength of concrete surface layer part |
| JP4686068B2 (en) * | 2001-07-13 | 2011-05-18 | 大成建設株式会社 | Method for measuring strength of concrete surface layer and variable setting device |
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