JPH06213872A - Method for measuring crystal grain diameter of steel plate - Google Patents
Method for measuring crystal grain diameter of steel plateInfo
- Publication number
- JPH06213872A JPH06213872A JP595693A JP595693A JPH06213872A JP H06213872 A JPH06213872 A JP H06213872A JP 595693 A JP595693 A JP 595693A JP 595693 A JP595693 A JP 595693A JP H06213872 A JPH06213872 A JP H06213872A
- Authority
- JP
- Japan
- Prior art keywords
- coercive force
- measured
- crystal grain
- steel plate
- steel sheet
- 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.)
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- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、鉄鋼業における例え
ば連続焼鈍炉の出側において、連続的に走行している冷
延鋼板の保磁力を非接触方式にて鋼板全長にわたってオ
ンラインで測定し、同時にその測定した保磁力を用いて
冷延鋼板の結晶粒径を求めることに適用される、鋼板の
結晶粒径測定方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the coercive force of a continuously running cold rolled steel sheet online in the non-contact manner over the entire length of the steel sheet, for example, on the exit side of a continuous annealing furnace in the steel industry. At the same time, the present invention relates to a method for measuring the crystal grain size of a steel sheet, which is applied to obtain the crystal grain size of a cold rolled steel sheet using the measured coercive force.
【０００２】[0002]
【従来の技術】一般に、磁性材料である鋼板の保磁力測
定方法としては、被測定鋼板から無端環状の試料を切り
出し、その試料に巻き付けた励磁コイルに励磁電流を流
して磁束が試料中を環状に通るようにし、試料に巻き付
けた検出コイルを用いて試料の磁化状態を調べることに
より、図６に示すように、磁束密度Ｂと磁界の強さＨと
の関係を示すＢ−Ｈ曲線（ヒステリシス曲線）を求め、
oc＝ofに相当するＨの値である保磁力を測定するように
した方法がとられている。2. Description of the Related Art Generally, as a method for measuring the coercive force of a steel sheet which is a magnetic material, an endless annular sample is cut out from the steel sheet to be measured, and an exciting current is passed through an exciting coil wound around the sample so that a magnetic flux is generated in the sample. As shown in FIG. 6, a B-H curve (hysteresis) indicating the relationship between the magnetic flux density B and the magnetic field strength H is obtained by investigating the magnetization state of the sample by using a detection coil wound around the sample. Curve),
A method is adopted in which the coercive force, which is the value of H corresponding to oc = of, is measured.
【０００３】ところで、鋼板の保磁力は鋼板の結晶粒径
に反比例すること、つまり鋼板の保磁力は鋼板の結晶粒
径の逆数に比例することが知られている（近角ほか：磁
性体ハンドブック，1070頁，朝倉書房，1987年）。そこ
で、この結晶粒径が鋼板の機械的性質を推定するパラメ
ータの一つであることから、冷延鋼板生産ラインにおい
て連続的に搬送・走行されている鋼板の機械的性質をそ
の鋼板全長にわたってオンラインで検査できるようにす
ることを目的として、本発明者らは、鋼板からその一部
を測定用試料として切り出すことなく鋼板の保磁力を測
定できるようにした鋼板保磁力測定装置を提案し（特願
平4−13271 号）、また、鋼板の保磁力を測定すること
によって間接的にその鋼板の結晶粒径を求めることにつ
いて提案している（第31回計測自動制御学会学術講演予
稿集， 655〜 656頁，1992年）。By the way, it is known that the coercive force of a steel sheet is inversely proportional to the crystal grain size of the steel sheet, that is, the coercive force of the steel sheet is proportional to the reciprocal of the crystal grain size of the steel sheet (Kikaku et al .: Handbook of Magnetic Materials, 1070, Asakura Shobo, 1987). Therefore, since this crystal grain size is one of the parameters for estimating the mechanical properties of the steel sheet, the mechanical properties of the steel sheet continuously conveyed and run in the cold-rolled steel sheet production line can be calculated online over the entire length of the steel sheet. The present inventors have proposed a steel plate coercive force measuring device capable of measuring the coercive force of a steel plate without cutting out a part of the steel plate as a measurement sample (for (Japanese Patent Application No. 4-13271), and it has been proposed to indirectly obtain the crystal grain size of a steel sheet by measuring the coercive force of the steel sheet (Proceedings of 31st Annual Meeting of the Society of Instrument and Control Engineers, 655). ~ 656, 1992).
【０００４】以下、先に提案しこの発明にも係る鋼板保
磁力測定装置について、その構成を示す図である図３
と、その動作を説明するためのタイミングチャート図で
ある図４とを参照しつつ説明する。鋼板保磁力測定装置
E1は、図３に示すように、Ｕ字型のコア（フェライトコ
ア）11を有する保磁力検出用ヘッド１と、保磁力測定装
置本体２とから構成されている。そして、保磁力測定装
置本体２は、保磁力検出用ヘッド１の励磁コイル13ａ，
13ｂに交流の励磁電流を供給する交流励磁用電源３と、
励磁コイル13ａ，13ｂに流れる励磁電流を検出し、これ
に相当する電圧信号を出力するシャント抵抗を用いた励
磁電流検出器４と、保磁力検出用ヘッド１の検出コイル
12に発生する誘起電圧と励磁電流検出器４からの励磁電
流とを入力とし、後述する信号処理を行うことで被測定
鋼板Ｓの保磁力を求めその信号を出力する信号処理装置
５とによって構成されている。FIG. 3 is a diagram showing the structure of a steel plate coercive force measuring device previously proposed and according to the present invention.
And FIG. 4 which is a timing chart for explaining the operation thereof. Steel plate coercive force measuring device
As shown in FIG. 3, E1 is composed of a coercive force detecting head 1 having a U-shaped core (ferrite core) 11 and a coercive force measuring device main body 2. The coercive force measuring device main body 2 includes the exciting coil 13a of the coercive force detecting head 1,
AC exciting power source 3 for supplying an alternating exciting current to 13b,
Exciting current detector 4 using a shunt resistor that detects an exciting current flowing through the exciting coils 13a and 13b and outputs a voltage signal corresponding thereto, and a detecting coil of the coercive force detecting head 1.
The signal processing device 5 receives the induced voltage generated in 12 and the exciting current from the exciting current detector 4 as input, and calculates the coercive force of the steel sheet S to be measured by performing signal processing described later, and outputs the signal. Has been done.
【０００５】上記保磁力検出用ヘッド１は、図３に示す
ように、Ｕ字型のコア11の両脚部の各々にコイルを施し
て、交流の励磁電流が供給されることで磁束が、交互
に、一方のコア脚部磁極面から出て被測定鋼板中を通っ
て他方のコア脚部磁極面へ入るように上記両コイルを直
列に接続して励磁コイル13ａ，13ｂとし、さらにコア中
央部に検出コイル12を施してなるものである。また、上
記信号処理装置５は、ゲート回路51、微分器52、ゼロ点
検出器53、第１サンプルホールド回路54ａ、第２サンプ
ルホールド回路54ｂ、及び、演算回路55によって構成さ
れている。ゲート回路51と微分器52及びゼロ点検出器53
は、被測定鋼板を磁化した際に、検出コイル12に発生す
る誘起電圧が磁化半サイクル毎に尖頭値（ピーク値）を
とった時点を検出するためのものであり、サンプルホー
ルド回路54ａ，54ｂは、検出コイル12に発生する誘起電
圧が先の磁化半サイクルにおいて尖頭値をとった時点の
励磁電流値と次の磁化半サイクルにおいて尖頭値をとっ
た時点の励磁電流値とを検出するための回路である。ま
た、演算回路55は、上記両励磁電流値の絶対値の平均値
を求め、その値に基づいて被測定鋼板の保磁力を求める
ためのものである。As shown in FIG. 3, the coercive force detecting head 1 has coils on both legs of a U-shaped core 11 and is supplied with an alternating exciting current so that magnetic fluxes alternate. Then, the two coils are connected in series to form the exciting coils 13a and 13b so as to come out from one magnetic pole surface of the core leg, pass through the steel plate to be measured, and enter the magnetic pole surface of the other core leg. The detection coil 12 is applied to the. The signal processing device 5 is composed of a gate circuit 51, a differentiator 52, a zero point detector 53, a first sample hold circuit 54a, a second sample hold circuit 54b, and an arithmetic circuit 55. Gate circuit 51, differentiator 52 and zero point detector 53
Is for detecting the time when the induced voltage generated in the detection coil 12 takes a peak value (peak value) every half cycle of magnetization when the steel sheet to be measured is magnetized. 54b detects the exciting current value when the induced voltage generated in the detection coil 12 takes a peak value in the previous magnetization half cycle and the exciting current value when the peak value is taken in the next magnetization half cycle. It is a circuit for doing. Further, the arithmetic circuit 55 is for obtaining the average value of the absolute values of the two exciting current values and for obtaining the coercive force of the steel sheet to be measured based on the average value.
【０００６】次に動作を説明すると、被測定鋼板Ｓの上
に、保磁力検出用ヘッド１をそのコア11の両脚部磁極面
と被測定鋼板Ｓとの間に隙間を持たせて配置する。そし
て、保磁力検出用ヘッド１の励磁コイル13ａ，13ｂに図
４の（ｅ）に示すように交流の励磁電流を流し、被測定
鋼板Ｓをその中に磁束を通して磁化すると、保磁力検出
用ヘッド１の検出コイル12には、図４の（ｂ）に示すよ
うに、磁化半サイクル毎にその極性が交互に変化する正
負のパルス状の誘起電圧が出力として発生する。保磁力
は磁束密度がゼロクロスする時の磁界の強さであるか
ら、磁束密度の時間微分を示すものである検出コイル12
の出力が尖頭値（ピーク値）をとる時点を検出し、その
時点の磁界の強さにあたる励磁電流値を検出することに
より、保磁力が求められる。To explain the operation, the coercive force detecting head 1 is arranged on the steel plate to be measured S with a gap between the magnetic pole surfaces of both legs of the core 11 and the steel plate to be measured S. Then, as shown in FIG. 4 (e), an alternating exciting current is passed through the exciting coils 13a, 13b of the coercive force detecting head 1 to magnetize the steel sheet to be measured S by passing a magnetic flux through it. As shown in FIG. 4 (b), positive and negative pulsed induced voltages whose polarities alternate every half magnetization cycle are generated in the detection coil 12 of No. 1 as an output. Since the coercive force is the strength of the magnetic field when the magnetic flux density crosses zero, it shows the time derivative of the magnetic flux density.
The coercive force can be obtained by detecting the time point when the output of 1 takes a peak value (peak value) and detecting the exciting current value corresponding to the strength of the magnetic field at that time point.
【０００７】さて、検出コイル12の出力がゲート回路51
及び微分器52に与えられ、ゲート回路51からは、図４の
（ｃ）に示すように、基準電位であるゼロボルト点に対
して設定された正の微小閾値を検出コイル12の出力が正
の極性において超えている期間と、負の微小閾値を検出
コイル12の出力が負の極性において超えている期間とで
ハイレベルとなる出力がゼロ点検出器53に入力される。
また、同時に、ゼロ点検出器53には、微分器52から図４
の（ｄ）に示す波形の信号が入力される。Now, the output of the detection coil 12 is the gate circuit 51.
And a differentiator 52, and from the gate circuit 51, as shown in FIG. 4 (c), the output of the detection coil 12 outputs a positive small threshold value set to the zero volt point which is the reference potential. A high-level output is input to the zero-point detector 53 during a period in which the polarity is exceeded and a period in which the output of the detection coil 12 exceeds the negative minute threshold value in the negative polarity.
At the same time, the zero point detector 53 has a differentiator from the differentiator 52 shown in FIG.
The signal having the waveform shown in (d) is input.
【０００８】ゼロ点検出器53は、ゲート回路51の出力が
ハイレベルの期間において微分器52の出力がゼロボルト
点を横切る時点、つまり、検出コイル12の出力が正の尖
頭値をとった時点と負の尖頭値をとった時点とをそれぞ
れ検出する。そして、検出コイル12の出力が正の尖頭値
をとった時、第１サンプルホールド回路54ａに第１サン
プルホールド指令信号S1を与える一方、検出コイル12の
出力が負の尖頭値をとった時、第２サンプルホールド回
路54ｂに第２サンプルホールド指令信号S2を与える。The zero-point detector 53 is used when the output of the differentiator 52 crosses the zero volt point during the period when the output of the gate circuit 51 is at a high level, that is, when the output of the detection coil 12 has a positive peak value. And when the negative peak value is taken, respectively. When the output of the detection coil 12 has a positive peak value, the first sample and hold command signal S1 is given to the first sample and hold circuit 54a, while the output of the detection coil 12 has a negative peak value. At this time, the second sample hold command signal S2 is given to the second sample hold circuit 54b.
【０００９】第１サンプルホールド回路54ａは、上記指
令信号S1が与えられたときの励磁電流検出器４の出力を
サンプリングして保持し、この検出した信号、すなわ
ち、検出コイル12の出力が正の尖頭値をとった時点にお
ける励磁コイル13ａ，13ｂの励磁電流値に相当する信号
（ＩH ）を演算回路55に出力する。また、第２サンプル
ホールド回路54ｂは、上記指令信号S2が与えられたとき
の励磁電流検出器４の出力をサンプリングして保持し、
この検出した信号、すなわち、検出コイル12の出力が負
の尖頭値をとった時点における励磁電流値に相当する信
号（−ＩH ）を演算回路55に出力する。The first sample and hold circuit 54a samples and holds the output of the exciting current detector 4 when the command signal S1 is given, and the detected signal, that is, the output of the detection coil 12 is positive. A signal (I H ) corresponding to the exciting current value of the exciting coils 13a and 13b at the time when the peak value is obtained is output to the arithmetic circuit 55. Further, the second sample hold circuit 54b samples and holds the output of the exciting current detector 4 when the command signal S2 is given,
The detected signal, i.e., outputs a signal corresponding to the exciting current value at the time the output of the detection coil 12 has taken a negative peak value (-I H) to the arithmetic circuit 55.
【００１０】演算回路55は、第１サンプルホールド回路
54ａの出力（ＩH ）と第２サンプルホールド回路54ｂの
出力（−ＩH ）とが与えられると、〔（ＩH ）−（−Ｉ
H ）〕／２の演算を行って被測定鋼板Ｓの保磁力に対応
する励磁電流値を求め、その励磁電流値に基づいて、予
め求めておいた励磁電流と磁界の強さとの関係から、被
測定鋼板Ｓの保磁力を求めてその信号を出力するように
している。The arithmetic circuit 55 is a first sample and hold circuit.
The output of 54a (I H) and the output of the second sample-and-hold circuit 54b when (-I H) and are given, [(I H) - (- I
H )] / 2 is calculated to obtain an exciting current value corresponding to the coercive force of the steel sheet S to be measured, and based on the exciting current value, from the relationship between the exciting current and the strength of the magnetic field which is obtained in advance, The coercive force of the steel plate S to be measured is obtained and the signal is output.
【００１１】そして従来は、保磁力検出用ヘッドを備え
た上記鋼板保磁力測定装置を用いて鋼板の保磁力の測定
を行い、先に述べたように保磁力と結晶粒径とが反比例
関係にあることを利用して、次に述べる方法にて被測定
鋼板の結晶粒径を求めるようにしていた。すなわち、ま
ず、予め、結晶粒径ｄが既知の鋼板についてその鋼板面
内におけるある一方向に沿わせて保磁力検出用ヘッドを
位置させ、その鋼板の保磁力Hcを測定しておく。そし
て、結晶粒径を測定すべき被測定鋼板についてその鋼板
面内における一方向に沿わせて上記保磁力検出用ヘッド
を位置させ、被測定鋼板の保磁力Hc′を測定し、その保
磁力Hc′と、上記既知の結晶粒径ｄとそれにおける上記
保磁力Hcとから、（ｄ・Hc）／Hc′の演算により被測定
鋼板の結晶粒径を求めるようにしていた。Conventionally, the coercive force of a steel sheet is measured by using the above-mentioned steel plate coercive force measuring device equipped with a coercive force detecting head, and as described above, the coercive force and the crystal grain size are in an inversely proportional relationship. Taking advantage of this, the crystal grain size of the steel sheet to be measured was determined by the method described below. That is, first, the coercive force detection head of a steel plate having a known crystal grain size d is positioned along a certain direction in the steel plate surface, and the coercive force Hc of the steel plate is measured in advance. Then, for the steel sheet to be measured whose crystal grain size is to be measured, the coercive force detection head is positioned along one direction in the steel sheet surface, the coercive force Hc 'of the steel sheet to be measured is measured, and the coercive force Hc is measured. 'And the known crystal grain size d and the coercive force Hc therewith, the crystal grain size of the steel sheet to be measured is determined by the calculation of (d · Hc) / Hc'.
【００１２】[0012]
【発明が解決しようとする課題】ところが、上記保磁力
検出用ヘッドを用いて保磁力を測定することによって間
接的にその鋼板の結晶粒径を測定するに際し、ある種の
鋼板ではその保磁力の値が圧延方向（長手方向）とこれ
と直交する方向（板幅方向）とで相当に異なり、保磁力
に方向依存性があることがわかった。図５は鋼板の保磁
力の方向依存性を示したものである。同図に示すデータ
は、Ｕ字型のコアに励磁及び検出用の各コイルを施して
なる上述した保磁力検出用ヘッドを被測定鋼板の上に位
置させてその平面内において角度30°ピッチにて１回転
させ、角度30°ごとにおける保磁力を、鋼板Ａ及び鋼板
Ｂの各々について測定して得たものである。なお、図５
においては、縦軸は保磁力相当値を示しており、横軸に
おける角度０°及び角度 180°における値が、保磁力検
出用ヘッドを鋼板中を通る磁束が圧延方向となるように
位置させたときのものである。図５から理解されるよう
に、鋼板Ａでは、板幅方向（圧延方向と直交する方向）
における保磁力（図５の角度90°， 270°における値）
は、圧延方向におけるそれの約2.5 倍程度の大きさとな
っている。However, when indirectly measuring the crystal grain size of the steel sheet by measuring the coercive force using the above-mentioned coercive force detecting head, the coercive force It was found that the values significantly differ between the rolling direction (longitudinal direction) and the direction orthogonal to this (plate width direction), and the coercive force has a direction dependence. FIG. 5 shows the direction dependence of the coercive force of the steel sheet. The data shown in the figure shows that the above-mentioned coercive force detection head, which is a U-shaped core provided with each coil for excitation and detection, is positioned on the steel plate to be measured, and at an angle of 30 ° pitch in the plane. It is obtained by measuring the coercive force at each angle of 30 ° for each of steel sheet A and steel sheet B by rotating the steel sheet once. Note that FIG.
In Fig., The vertical axis represents the coercive force equivalent value, and the values at the angle 0 ° and the angle 180 ° on the horizontal axis were set so that the magnetic flux passing through the steel plate was in the rolling direction. Time. As can be seen from FIG. 5, in the steel plate A, the plate width direction (direction orthogonal to the rolling direction)
Coercive force (value at angles of 90 ° and 270 ° in Fig. 5)
Is about 2.5 times larger than that in the rolling direction.
【００１３】このように、ある種の鋼板ではその保磁力
に大きな方向依存性があり、保磁力の方向依存性の程度
は、鋼板によって異なっている。このため、上記従来の
方法では、予め結晶粒径ｄが既知の鋼板について測定さ
れた保磁力Hcと、結晶粒径を測定すべき被測定鋼板につ
いて測定された保磁力Hc′との保磁力測定方向に関する
対応関係が不一致の場合、例えば、結晶粒径ｄが既知の
鋼板において上記保磁力Hcが圧延方向における測定値で
あり、被測定鋼板において上記保磁力Hc′が圧延方向と
直交する方向における測定値であるような場合、（ｄ・
Hc）／Hc′の演算により求めた被測定鋼板の結晶粒径
は、実際の結晶粒径に対し大きな誤差が生じたものとな
ることがあるという問題点があった。As described above, the coercive force of a certain type of steel sheet has a large directional dependency, and the degree of the directional dependency of the coercive force varies depending on the steel sheet. Therefore, in the above-mentioned conventional method, the coercive force Hc measured in advance for a steel sheet having a known crystal grain size d and the coercive force Hc ′ measured for the steel sheet to be measured whose crystal grain size is to be measured. When the correspondences regarding the directions do not match, for example, the coercive force Hc is a measured value in the rolling direction in a steel sheet having a known crystal grain size d, and the coercive force Hc ′ in the measured steel sheet is in a direction orthogonal to the rolling direction. If it is a measured value, (d
There is a problem that the crystal grain size of the steel sheet to be measured, which is obtained by the calculation of Hc) / Hc ′, may have a large error with respect to the actual crystal grain size.
【００１４】この発明は、上記従来の問題点を解消する
ためになされたものであって、コアに鋼板磁化用の励磁
コイルと磁化状態検出用の検出コイルとを施してなる保
磁力検出用ヘッドを用いて被測定鋼板の保磁力を測定す
ることによって間接的にその被測定鋼板の結晶粒径を求
めるに際し、保磁力の方向依存性による影響をなくして
結晶粒径を正確に求めることができる、鋼板の結晶粒径
測定方法の提供を目的とするものである。The present invention has been made to solve the above-mentioned conventional problems, and a coercive force detecting head having a core provided with an exciting coil for magnetizing a steel sheet and a detecting coil for detecting a magnetized state. By indirectly measuring the coercive force of a steel plate to be measured using, the crystal grain size can be accurately obtained without the influence of the direction dependence of the coercive force. The purpose of the present invention is to provide a method for measuring the crystal grain size of a steel sheet.
【００１５】[0015]
【課題を解決するための手段】上記の目的を達成するた
めに、この発明による鋼板の結晶粒径測定方法は、コア
に鋼板磁化用の励磁コイルと磁化状態検出用の検出コイ
ルとを施してなる保磁力検出用ヘッドを用いて被測定鋼
板の保磁力を測定することによって間接的にその被測定
鋼板の結晶粒径を求める方法において、予め、結晶粒径
ｄが既知の鋼板について鋼板面内の少なくとも直交する
二方向における各保磁力を前記保磁力検出用ヘッドを用
いて測定し、それらを平均したものを保磁力平均値ＨCA
として求めておき、次に結晶粒径を測定すべき被測定鋼
板について鋼板面内の少なくとも直交する二方向におけ
る各保磁力を前記保磁力検出用ヘッドを用いて測定し、
それらを平均して保磁力平均値ＨCA′を求め、その保磁
力平均値ＨCA′と、前記既知の結晶粒径ｄとそれにおけ
る前記保磁力平均値ＨCAとから、（ｄ・ＨCA）／Ｈ CA′
の演算により被測定鋼板の結晶粒径を求めることを特徴
とする。[Means for Solving the Problems]
For the purpose of measuring the grain size of the steel sheet according to the present invention,
An exciting coil for magnetizing a steel sheet and a detection coil for detecting the magnetized state
Steel to be measured using a coercive force detection head
Indirect measurement of the coercive force of the plate
In the method of determining the crystal grain size of the steel sheet, the crystal grain size is calculated in advance.
d is at least orthogonal in the plane of the steel plate for a known steel plate
For each coercive force in two directions, use the coercive force detection head
Measured and averaged them to obtain the coercive force average value HCA
Steel to be measured whose crystal grain size should be measured next
The plate should be placed in at least two orthogonal directions in the plane
Measuring each coercive force using the coercive force detection head,
Coercive force average value H by averaging themCA′, The coercive force
Force average value HCA'And the known grain size d and
Average coercive force HCAFrom, (d ・ HCA) / H CA′
The feature is that the crystal grain size of the steel sheet to be measured is calculated by
And
【００１６】[0016]
【作用】この発明による鋼板の結晶粒径測定方法におい
ては、鋼板面内における少なくとも直交する二方向にお
ける各保磁力を保磁力検出用ヘッドを用いて測定し、そ
れら測定値を平均したものである保磁力平均値を、結晶
粒径を求めるための情報として用いるようにしている。
これにより、鋼板における保磁力平均値と結晶粒径との
対応関係が一義的に定められて保磁力の方向依存性の影
響を除去でき、結晶粒径を正確に求めることができる。In the method for measuring the grain size of a steel sheet according to the present invention, each coercive force in at least two orthogonal directions in the plane of the steel sheet is measured using a coercive force detecting head, and the measured values are averaged. The coercive force average value is used as information for obtaining the crystal grain size.
Thereby, the correspondence between the average value of coercive force and the crystal grain size in the steel sheet is uniquely determined, the influence of the direction dependence of the coercive force can be removed, and the crystal grain size can be accurately obtained.
【００１７】[0017]
【実施例】以下、この発明をその実施例を示す図面に基
づき説明する。図１はこの発明による方法を実施するた
めの結晶粒径測定装置の構成の一例を示す図である。図
１に示すように、結晶粒径測定装置は、この実施例では
二つの鋼板保磁力測定装置E1，E1′と、これらに接続さ
れたパーソナルコンピュータの如きコンピュータ10とに
より構成されている。なおここで、被測定鋼板Ｓに対し
その上に非接触にて鋼板圧延方向に沿うように支持具
（図示省略）により位置される保磁力検出用ヘッド１、
及び保磁力測定装置本体２を有する一方の鋼板保磁力測
定装置E1、並びに、上記一方の保磁力検出用ヘッド１に
近接して配され、被測定鋼板Ｓに対しその上に非接触に
て鋼板圧延方向と直交する方向（板幅方向）に沿うよう
に支持具（図示省略）により位置される保磁力検出用ヘ
ッド１′、及び保磁力測定装置本体２′を有する他方の
鋼板保磁力測定装置E1′の構成は、先に説明した図３に
示すものと同一であるからその説明を省略する。コンピ
ュータ10は、鋼板保磁力測定装置E1，E1′から入力され
る被測定鋼板Ｓの二方向についての保磁力を用いて、後
述する手順に従って被測定鋼板Ｓの結晶粒径を演算によ
り求めるためのものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the drawings showing its embodiments. FIG. 1 is a diagram showing an example of the structure of a crystal grain size measuring apparatus for carrying out the method according to the present invention. As shown in FIG. 1, the crystal grain size measuring device is composed of two steel plate coercive force measuring devices E1 and E1 'in this embodiment, and a computer 10 such as a personal computer connected to these. In addition, here, a coercive force detection head 1, which is positioned by a support tool (not shown) so as to follow the steel plate to be measured S in a non-contact manner along the steel plate rolling direction,
And one steel plate coercive force measuring device E1 having the coercive force measuring device main body 2 and the one coercive force detecting head 1 arranged in proximity to the steel plate to be measured S without contacting the steel plate S to be measured. The other steel plate coercive force measuring device having a coercive force detecting head 1'positioned by a supporting member (not shown) along a direction (plate width direction) orthogonal to the rolling direction, and a coercive force measuring device main body 2 '. Since the configuration of E1 'is the same as that shown in FIG. 3 described above, the description thereof is omitted. The computer 10 uses the coercive force in two directions of the steel plate to be measured S input from the steel plate coercive force measuring devices E1 and E1 'to calculate the crystal grain size of the steel plate to be measured S according to the procedure described below. It is a thing.
【００１８】次に上記装置を用いて行うこの発明による
結晶粒径測定方法を説明する。まず、サンプル用鋼板を
用意し、その結晶粒径を顕微鏡写真による周知の切断法
により測定し、その結晶粒径の値ｄをデータとしてコン
ピュータ10に入力する。さらに、そのサンプル用鋼板に
ついて、上記一方の保磁力検出用ヘッド１を鋼板圧延方
向に沿わせて位置させた際の保磁力を測定し、その測定
値ＨC1をデータとしてコンピュータ10に入力するととも
に、他方の保磁力検出用ヘッド１′を板幅方向（圧延方
向と直交する方向）に沿わせて位置させた際の保磁力を
測定し、その測定値ＨC2をデータとしてコンピュータ10
に入力する。コンピュータ10は、ＨCA＝（ＨC1＋ＨC2）
／２の演算により上記二つの値ＨC1，ＨC2を算術平均し
たものを保磁力平均値ＨCAとして求め、上記既知の結晶
粒径ｄとそれにおける保磁力平均値ＨCAとをデータとし
て記憶しておく。Next, the crystal grain size measuring method according to the present invention, which is carried out by using the above apparatus, will be described. First, a sample steel plate is prepared, its crystal grain size is measured by a known cutting method using a micrograph, and the value d of the crystal grain size is input to the computer 10 as data. Further, with respect to the sample steel plate, the coercive force when the one coercive force detection head 1 is positioned along the steel plate rolling direction is measured, and the measured value H C1 is input to the computer 10 as data. The coercive force when the other coercive force detecting head 1'is positioned along the plate width direction (direction orthogonal to the rolling direction), and the measured value H C2 is used as data in the computer 10
To enter. The computer 10 has H CA = (H C1 + H C2 ).
The coercive force average value H CA is obtained by arithmetically averaging the above two values H C1 and H C2 by the calculation of / 2, and the known crystal grain size d and the coercive force average value H CA therein are stored as data. I'll do it.
【００１９】次いで、結晶粒径を測定すべき被測定鋼板
Ｓについて、上記一方の保磁力検出用ヘッド１を鋼板圧
延方向に沿わせて位置させた際の保磁力が保磁力測定装
置本体２により測定され、測定された保磁力の値ＨC1′
を示す出力がコンピュータ10に与えられるとともに、他
方の保磁力検出用ヘッド１′を板幅方向（圧延方向と直
交する方向）に沿わせて位置させた際の保磁力が保磁力
測定装置本体２′により測定され、測定された保磁力の
値ＨC2′を示す出力がコンピュータ10に与えられる。Next, for the steel sheet S to be measured whose crystal grain size is to be measured, the coercive force when the one coercive force detecting head 1 is positioned along the rolling direction of the steel sheet is measured by the coercive force measuring device main body 2. The measured and measured coercive force value H C1 ′
Is given to the computer 10, and the coercive force when the other coercive force detecting head 1'is positioned along the strip width direction (direction orthogonal to the rolling direction), the coercive force measuring device main body 2 An output indicative of the measured coercive force value H C2 ′ is provided to computer 10 as measured by
【００２０】そして、コンピュータ10により、ＨCA′＝
（ＨC1′＋ＨC2′）／２の演算により保磁力平均値
ＨCA′が求められ、この保磁力平均値ＨCA′と、上記予
め求めておいた既知の結晶粒径ｄとそれにおける保磁力
平均値ＨCAとから、鋼板の保磁力は鋼板の結晶粒径に反
比例する関係を利用して、ｄ′＝（ｄ・ＨCA）／ＨCA′
の演算により被測定鋼板Ｓの結晶粒径ｄ′が求められ
る。Then, the computer 10 causes H CA ′ =
The average value of coercive force H CA ′ is obtained by the calculation of (H C1 ′ + H C2 ′) / 2, and this average value of coercive force H CA ′ and the previously known known grain size d and the coercive force thereat are obtained. From the magnetic force average value H CA , the coercive force of the steel sheet is inversely proportional to the crystal grain size of the steel sheet, and d ′ = (d · H CA ) / H CA ′
The crystal grain size d ′ of the steel sheet S to be measured is obtained by the calculation of
【００２１】このように、この発明による方法による
と、コアに鋼板磁化用の励磁コイルと磁化状態検出用の
検出コイルとを施してなる保磁力検出用ヘッドを用いて
鋼板の保磁力を測定することによって間接的にその鋼板
の結晶粒径を求めるに際し、鋼板面内における少なくと
も直交する二方向における各保磁力を保磁力検出用ヘッ
ドを用いて測定し、それら測定値を平均したものである
保磁力平均値を、結晶粒径を求めるための情報として用
いるようにしたので、鋼板における保磁力平均値と結晶
粒径との対応関係が一義的に定められて保磁力の方向依
存性の影響を除去でき、結晶粒径を正確に求めることが
できる。As described above, according to the method of the present invention, the coercive force of the steel sheet is measured by using the coercive force detecting head having the core provided with the exciting coil for magnetizing the steel sheet and the detecting coil for detecting the magnetization state. When indirectly determining the crystal grain size of the steel sheet, the coercive force in at least two orthogonal directions in the plane of the steel sheet is measured using a coercive force detection head, and the measured values are averaged. Since the magnetic force average value is used as the information for obtaining the crystal grain size, the correspondence between the coercive force average value and the crystal grain size in the steel sheet is uniquely determined, and the influence of the direction dependency of the coercive force is determined. It can be removed and the crystal grain size can be accurately determined.
【００２２】なお、この発明による方法においては、保
磁力平均値としては、図１に示す実施例では、被測定鋼
板Ｓの鋼板圧延方向及び板幅方向（鋼板圧延方向と直交
する方向）における各保磁力を測定し、その平均値を用
いるようにしたが、図５から理解されるように、圧延方
向と板幅方向の既知、未知に無関係に、単に直交する二
方向における各保磁力を平均したものを用いるようにし
てもよい。In the method according to the present invention, as the average coercive force, in the embodiment shown in FIG. 1, each of the steel plate to be measured S in the steel plate rolling direction and the plate width direction (direction orthogonal to the steel plate rolling direction) is measured. The coercive force was measured and the average value was used. However, as can be understood from FIG. 5, the coercive force in the two orthogonal directions is averaged regardless of whether the rolling direction and the strip width direction are known or unknown. You may make it use what was done.
【００２３】また、図１に示す実施例では、二つの鋼板
保磁力測定装置E1，E1′を使用し、直交する二方向に保
磁力検出用ヘッド１，１′をひとつずつ位置させるよう
にしたが、例えば保磁力検出用ヘッドの励磁コイル端子
及び検出コイル端子の通電をスリップリング方式とし、
保磁力検出用ヘッドを回転可能な構成とすることによ
り、当然ながら、鋼板保磁力測定装置は一つですむこと
になる。図２は、保磁力平均値相当値と結晶粒径との関
係を示す図である。図２に示すデータは、鋼中の炭素値
と熱処理条件とを変えて、結晶粒径だけを変化させたサ
ンプル用鋼板を作製し、それらにおける保磁力平均値を
測定して得たものである。縦軸は、保磁力検出用ヘッド
を角度30゜ピッチにて１回転させ、その角度30゜ごとに
おける各保磁力を算術平均した保磁力平均値を示し、横
軸は、切断法により測定した結晶粒径の逆数を示してお
り、ほぼ線形な結果が得られている。In the embodiment shown in FIG. 1, two steel plate coercive force measuring devices E1 and E1 'are used, and the coercive force detecting heads 1 and 1'are respectively positioned in two orthogonal directions. However, for example, the excitation coil terminal and the detection coil terminal of the coercive force detection head are energized by a slip ring system,
By making the coercive force detection head rotatable, as a matter of course, only one steel plate coercive force measuring device is required. FIG. 2 is a view showing the relationship between the equivalent value of the coercive force average value and the crystal grain size. The data shown in FIG. 2 were obtained by changing the carbon value in the steel and the heat treatment conditions to prepare sample steel sheets in which only the crystal grain size was changed, and measuring the average coercive force in them. . The vertical axis represents the coercive force average value obtained by arithmetically averaging the coercive force at each angle of 30 ° by rotating the coercive force detecting head once at an angle of 30 °, and the horizontal axis represents the crystal measured by the cutting method. The reciprocal of the particle size is shown, and almost linear results are obtained.
【００２４】[0024]
【発明の効果】以上述べたように、この発明による鋼板
の結晶粒径測定方法によると、コアに鋼板磁化用の励磁
コイルと磁化状態検出用の検出コイルとを施してなる保
磁力検出用ヘッドを用いて鋼板の保磁力を測定すること
によって間接的にその鋼板の結晶粒径を求めるに際し、
鋼板面内における少なくとも直交する二方向における各
保磁力を保磁力検出用ヘッドを用いて測定し、それらを
平均したものである保磁力平均値を、結晶粒径を間接的
に測定するための情報として用いるようにしたものであ
るから、鋼板における保磁力平均値と結晶粒径との対応
関係が一義的に定められて保磁力の方向依存性の影響を
除去でき、結晶粒径を正確に求めることができる。これ
により、冷延鋼板生産ラインにおいて連続的に走行して
いる鋼板の結晶粒径をその鋼板全長にわたってオンライ
ンにて正確に測定することが可能となる。As described above, according to the method for measuring the grain size of a steel sheet according to the present invention, a coercive force detecting head having a core provided with an exciting coil for magnetizing the steel sheet and a detecting coil for detecting a magnetization state. When indirectly determining the crystal grain size of a steel sheet by measuring the coercive force of the steel sheet using
Information for indirectly measuring the crystal grain size is obtained by measuring the coercive force in at least two orthogonal directions in the plane of the steel sheet using a coercive force detecting head and averaging them. Therefore, the correspondence between the average value of coercive force and the crystal grain size in the steel sheet is uniquely determined, the influence of the direction dependence of the coercive force can be removed, and the crystal grain size can be accurately determined. be able to. As a result, it becomes possible to accurately measure the crystal grain size of the steel sheet continuously running in the cold-rolled steel sheet production line online over the entire length of the steel sheet.
【図１】この発明による方法を実施するための結晶粒径
測定装置の構成の一例を示す図である。FIG. 1 is a diagram showing an example of the configuration of a crystal grain size measuring apparatus for carrying out the method according to the present invention.
【図２】この発明に係る保磁力平均値相当値と結晶粒径
との関係を示す図である。FIG. 2 is a diagram showing a relationship between a coercive force average value equivalent value and a crystal grain size according to the present invention.
【図３】先に提案しこの発明に係る鋼板保磁力測定装置
の構成を示す図である。FIG. 3 is a diagram showing a configuration of a steel plate coercive force measuring device according to the present invention that has been previously proposed.
【図４】図３に示す鋼板保磁力測定装置の動作を説明す
るためのタイミングチャート図である。4 is a timing chart diagram for explaining the operation of the steel plate coercive force measuring device shown in FIG. 3. FIG.
【図５】鋼板の保磁力の方向依存性を示す図である。FIG. 5 is a diagram showing the direction dependence of the coercive force of a steel sheet.
【図６】Ｂ−Ｈ曲線（ヒステリシス曲線）を示す図であ
る。FIG. 6 is a diagram showing a BH curve (hysteresis curve).
１，１′…保磁力検出用ヘッド 11…コア 12…検出コ
イル 13ａ，13ｂ…励磁コイル ２，２′…保磁力測定
装置本体 ３…交流励磁用電源 ４…励磁電流検出器
５…信号処理装置 51…ゲート回路 52…微分器 53…
ゼロ点検出器 54ａ…第１サンプルホールド回路 54ｂ…第２サンプル
ホールド回路 55…演算回路 10…コンピュータ E1，
E1′…鋼板保磁力測定装置 Ｓ…被測定鋼板1, 1 '... Coercive force detection head 11 ... Core 12 ... Detection coil 13a, 13b ... Excitation coil 2, 2' ... Coercive force measuring device main body 3 ... AC excitation power supply 4 ... Excitation current detector
5 ... Signal processing device 51 ... Gate circuit 52 ... Differentiator 53 ...
Zero point detector 54a ... First sample and hold circuit 54b ... Second sample and hold circuit 55 ... Arithmetic circuit 10 ... Computer E1,
E1 '... Steel plate coercive force measuring device S ... Steel plate to be measured
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小川 岳夫 兵庫県神戸市西区高塚台１丁目５番５号 株式会社神戸製鋼所神戸総合技術研究所内 (72)発明者 赤松 勝 兵庫県神戸市西区高塚台１丁目５番５号 株式会社神戸製鋼所神戸総合技術研究所内 (72)発明者 森本 勉 兵庫県神戸市西区高塚台１丁目５番５号 株式会社神戸製鋼所神戸総合技術研究所内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Takeo Ogawa Inventor Takeo Ogawa 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Inside Kobe Research Institute of Kobe Steel, Ltd. (72) Masaru Akamatsu Takatsuka, Nishi-ku, Kobe-shi, Hyogo 1-5-5 Taiwan Kobe Works, Kobe Steel Co., Ltd. (72) Inventor Tsutomu Morimoto 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Works, Kobe Steel Co., Ltd.
Claims (1)
態検出用の検出コイルとを施してなる保磁力検出用ヘッ
ドを用いて被測定鋼板の保磁力を測定することによって
間接的にその被測定鋼板の結晶粒径を求める方法におい
て、予め、結晶粒径ｄが既知の鋼板について鋼板面内の
少なくとも直交する二方向における各保磁力を前記保磁
力検出用ヘッドを用いて測定し、それらを平均したもの
を保磁力平均値ＨCAとして求めておき、次に結晶粒径を
測定すべき被測定鋼板について鋼板面内の少なくとも直
交する二方向における各保磁力を前記保磁力検出用ヘッ
ドを用いて測定し、それらを平均して保磁力平均値
ＨCA′を求め、その保磁力平均値ＨCA′と、前記既知の
結晶粒径ｄとそれにおける前記保磁力平均値ＨCAとか
ら、（ｄ・ＨCA）／ＨCA′の演算により被測定鋼板の結
晶粒径を求めることを特徴とする鋼板の結晶粒径測定方
法。1. A coercive force of a steel sheet to be measured is indirectly measured by measuring a coercive force of a steel sheet to be measured by using a coercive force detecting head having a core provided with an exciting coil for magnetizing a steel sheet and a detecting coil for detecting a magnetization state. In the method for determining the crystal grain size of a measurement steel plate, each coercive force in a steel plate having a known crystal grain size d in at least two orthogonal directions in the plane of the steel plate is measured in advance by using the coercive force detecting head, and these are measured. An average value is obtained as a coercive force average value H CA , and then the coercive force in at least two orthogonal directions in the steel plate surface of the steel plate to be measured whose crystal grain size is to be measured using the coercive force detection head. And average them to obtain a coercive force average value H CA ′, and from the coercive force average value H CA ′, the known crystal grain size d and the coercive force average value H CA therein, ( d ・ H CA ) / H CA A method for measuring the grain size of a steel sheet, characterized in that the grain size of the steel sheet to be measured is obtained by the calculation of '.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP595693A JPH06213872A (en) | 1993-01-18 | 1993-01-18 | Method for measuring crystal grain diameter of steel plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP595693A JPH06213872A (en) | 1993-01-18 | 1993-01-18 | Method for measuring crystal grain diameter of steel plate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06213872A true JPH06213872A (en) | 1994-08-05 |
Family
ID=11625350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP595693A Withdrawn JPH06213872A (en) | 1993-01-18 | 1993-01-18 | Method for measuring crystal grain diameter of steel plate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06213872A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007146244A (en) * | 2005-11-29 | 2007-06-14 | Jfe Steel Kk | Primary recrystallization-annealing facility for grain-oriented magnetic steel sheet |
| JP2009074813A (en) * | 2007-09-19 | 2009-04-09 | Jfe Steel Kk | Method and device for detecting magnetic characteristic fluctuation portion of magnetic material |
| JP2009236896A (en) * | 2008-03-03 | 2009-10-15 | Nippon Steel Corp | Magnetic characteristic measuring device and magnetic characteristic measuring method |
| JP2010117158A (en) * | 2008-11-11 | 2010-05-27 | Daido Steel Co Ltd | Inspection device and inspection method |
| JP2017198572A (en) * | 2016-04-28 | 2017-11-02 | 株式会社東芝 | Magnetic characteristic measurement probe, magnetic characteristic measurement system, magnetic characteristic measurement method and degradation evaluation method |
| US20220205950A1 (en) * | 2019-04-22 | 2022-06-30 | Jfe Steel Corporation | Metal structure evaluator for rolled steel sheets, method for evaluating metal structure of rolled steel sheet, production facility of steel product, method for manufacturing steel product, and method of quality management of steel product |
-
1993
- 1993-01-18 JP JP595693A patent/JPH06213872A/en not_active Withdrawn
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007146244A (en) * | 2005-11-29 | 2007-06-14 | Jfe Steel Kk | Primary recrystallization-annealing facility for grain-oriented magnetic steel sheet |
| JP2009074813A (en) * | 2007-09-19 | 2009-04-09 | Jfe Steel Kk | Method and device for detecting magnetic characteristic fluctuation portion of magnetic material |
| JP2009236896A (en) * | 2008-03-03 | 2009-10-15 | Nippon Steel Corp | Magnetic characteristic measuring device and magnetic characteristic measuring method |
| JP2010117158A (en) * | 2008-11-11 | 2010-05-27 | Daido Steel Co Ltd | Inspection device and inspection method |
| JP2017198572A (en) * | 2016-04-28 | 2017-11-02 | 株式会社東芝 | Magnetic characteristic measurement probe, magnetic characteristic measurement system, magnetic characteristic measurement method and degradation evaluation method |
| US20220205950A1 (en) * | 2019-04-22 | 2022-06-30 | Jfe Steel Corporation | Metal structure evaluator for rolled steel sheets, method for evaluating metal structure of rolled steel sheet, production facility of steel product, method for manufacturing steel product, and method of quality management of steel product |
| US11933762B2 (en) * | 2019-04-22 | 2024-03-19 | Jfe Steel Corporation | Metal structure evaluator for rolled steel sheets, method for evaluating metal structure of rolled steel sheet, production facility of steel product, method for manufacturing steel product, and method of quality management of steel product |
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