JP3140244B2 - Grain size measurement method - Google Patents
Grain size measurement methodInfo
- Publication number
- JP3140244B2 JP3140244B2 JP05043127A JP4312793A JP3140244B2 JP 3140244 B2 JP3140244 B2 JP 3140244B2 JP 05043127 A JP05043127 A JP 05043127A JP 4312793 A JP4312793 A JP 4312793A JP 3140244 B2 JP3140244 B2 JP 3140244B2
- Authority
- JP
- Japan
- Prior art keywords
- grain size
- ultrasonic
- frequency
- crystal grain
- measured
- 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.)
- Expired - Fee Related
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- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、鋼板等の結晶粒度を非
破壊で測定する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for non-destructively measuring the grain size of a steel sheet or the like.
【０００２】[0002]
【従来の技術】鋼材などの結晶粒度は、その強度や靱性
などの機械的性質と密接な関係があるため、これを測定
することにより製品の品質保証および品質向上に役立て
ることが重要である。一般に鋼材などの結晶粒度の測定
は、製品の一部を抜き取り、これを研摩仕上げして腐食
させて試験片を作製し、腐食面に現れた結晶粒を顕微鏡
で観察して行われている。しかし、この方法では破壊測
定となるため、製品の全長にわたる測定ができないばか
りか、試験片の作製に多大な時間を要し、また顕微鏡観
察時に測定者の主観が入るため、信頼性に欠けるという
問題がある。2. Description of the Related Art The grain size of a steel material or the like is closely related to its mechanical properties such as strength and toughness. Therefore, it is important to measure the grain size to contribute to quality assurance and quality improvement of products. Generally, the measurement of the grain size of a steel material or the like is performed by extracting a part of the product, polishing and corroding the product to prepare a test piece, and observing a crystal grain appearing on the corroded surface with a microscope. However, since this method is a destructive measurement, not only is it not possible to measure over the entire length of the product, but it also takes a lot of time to prepare test specimens, and it lacks reliability because the subjectivity of the measurer enters during microscopic observation. There's a problem.
【０００３】このため、被測定体内に伝播する超音波の
減衰量が結晶粒度によって変化することを利用した結晶
粒度の非破壊測定方法が、たとえば特公昭58− 31867号
公報や特開昭60− 35253号公報などに提案されている。
ここで、超音波減衰量を利用した結晶粒度の測定法の原
理について説明する。周波数ｆの超音波を鋼材などの被
測定体内に伝播させたとき、超音波音圧はその進行とと
もに減衰する。このとき単位進行距離当たりの減衰量を
減衰定数という。超音波の減衰する形態は、超音波の波
長をλ（＝Ｖ／ｆ；ここで、Ｖは被測定体内の超音波音
速）、被測定体の結晶粒度をＤとしたとき、両者の比λ
／Ｄの大小により異なる。すなわち、減衰定数αは、レ
イリー散乱領域であるλ／Ｄ≫１のときｆ4 に、またス
トカスティック散乱領域であるλ／Ｄ≒１のときにｆ3
に、さらに拡散散乱領域であるλ／Ｄ＜１のときｆ
2 に、それぞれ比例する関係にある。このうち、レイリ
ー散乱領域では、減衰定数αと周波数ｆ、結晶粒度Ｄと
の間に、 α＝ａ・Ｄ3 ・ｆ4 ……………(1) なる関係が成立する。ここで、ａは被測定体に固有の定
数である。したがって、周波数ｆの超音波により減衰定
数αを測定すれば、 Ｄ＝3 √｛α／（ａ・ｆ4 ）｝ ……………(2) により結晶粒度が求められる。このとき、λ／Ｄ（＝Ｖ
／（ｆ・Ｄ））≫１なるレイリー散乱領域を充たす超音
波周波数ｆで測定する必要があるが、被測定体の結晶粒
度Ｄは予めわからないので、何らかの工夫が必要であ
る。For this reason, a nondestructive measuring method of the crystal grain size utilizing the fact that the attenuation of the ultrasonic wave propagating in the body to be measured varies depending on the crystal grain size is disclosed in, for example, Japanese Patent Publication No. 58-31867 and Japanese Patent Application Laid-Open No. It is proposed in, for example, Japanese Patent No. 35253.
Here, the principle of the method for measuring the crystal grain size using the ultrasonic attenuation will be described. When an ultrasonic wave having a frequency f is propagated into a measurement object such as a steel material, the ultrasonic sound pressure attenuates as the ultrasonic wave advances. At this time, the amount of attenuation per unit traveling distance is called an attenuation constant. When the ultrasonic wave is attenuated, the wavelength of the ultrasonic wave is λ (= V / f; where V is the ultrasonic sound velocity in the measured object) and the crystal grain size of the measured object is D, and the ratio λ between them is λ.
It depends on the magnitude of / D. That is, the attenuation constant α is f 4 when λ / D≫1 which is the Rayleigh scattering region, and f 3 when λ / D ≒ 1 which is the stochastic scattering region.
In addition, when λ / D <1, which is a diffuse scattering region, f
2 are in proportion to each other. Among them, in the Rayleigh scattering region, the following relationship is established between the attenuation constant α, the frequency f, and the crystal grain size D: α = a · D 3 · f 4 (1) Here, a is a constant unique to the measured object. Therefore, if the attenuation constant α is measured by an ultrasonic wave having a frequency f, the crystal grain size can be obtained from D = 3 {α / (a · f 4 )} (2) At this time, λ / D (= V
/ (F · D)) ≫1 needs to be measured at the ultrasonic frequency f that satisfies the Rayleigh scattering region. However, since the crystal grain size D of the measured object is not known in advance, some contrivance is required.
【０００４】ところで、前記した特公昭58− 31867号の
方法は、超音波の周波数ｆを変化させて各周波数におけ
る減衰定数αを測定し、このαが2.0 dB/cm 以上になっ
たときの値を用いて、 α＝0.6 ×Ｄ3 ・ｆ4 ……………(3) なる関係式から結晶粒度Ｄを求めるものである。According to the method of Japanese Patent Publication No. 58-31867, the attenuation constant α at each frequency is measured by changing the frequency f of the ultrasonic wave, and the value obtained when this α becomes 2.0 dB / cm or more is measured. Is used to determine the crystal grain size D from the relational expression: α = 0.6 × D 3 · f 4 (3)
【０００５】また、特開昭60− 35253号の方法は、レイ
リー散乱領域外でも結晶粒度Ｄを求めることができるよ
うに、周波数ｆの超音波により減衰定数αを測定した
後、ｆ／αの大きさによりＤを算出する式を選択する方
法をとっている。すなわち、Ｄを求める関係式を下記
(4) 式 α＝ａi ・Ｄn ・ｆn+1 ……………(4) とし、この冪指数ｎおよび係数ａi の値をｆ／αの大き
さにより採択して結晶粒度Ｄを算出するものである。In the method disclosed in Japanese Patent Application Laid-Open No. 60-35253, the attenuation constant α is measured by an ultrasonic wave having a frequency f so that the crystal grain size D can be obtained even outside the Rayleigh scattering region. A method of selecting an expression for calculating D according to the size is adopted. That is, the relational expression for obtaining D is
(4) Equation α = a i · D n · f n + 1 (4), and the value of the power exponent n and the coefficient a i are adopted according to the magnitude of f / α to obtain the crystal grain size D. Is calculated.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、前記特
公昭58− 31867号の方法は、超音波減衰定数αがα≧2.
0 (dB/cm) となる領域がレイリー散乱領域と一致するこ
とを前提としているが、本発明者らの実験によれば、α
の大きさは超音波測定機器などに依存することもあっ
て、上記範囲すなわちα≧2.0 (dB/cm) となる領域は必
ずしもレイリー散乱領域を充たさず、したがって結晶粒
度測定精度が悪いことがわかった。However, according to the method of Japanese Patent Publication No. 58-31867, the ultrasonic attenuation constant α is α ≧ 2.
It is assumed that the region where 0 (dB / cm) coincides with the Rayleigh scattering region.
The size depends on the ultrasonic measurement equipment, etc., and the above range, that is, the region where α ≧ 2.0 (dB / cm) does not necessarily satisfy the Rayleigh scattering region, and therefore, the accuracy of crystal grain size measurement is poor. Was.
【０００７】また、特開昭60− 35253号の方法では、被
測定体の結晶粒度により相異なる近似式を適用すること
になり、測定精度が大幅に劣化する場合があるという問
題があった。本発明は、上記のような従来技術の有する
課題を解決すべく、超音波を利用した非破壊での高精度
な結晶粒度測定方法を提供することを目的とする。In the method disclosed in Japanese Patent Application Laid-Open No. Sho 60-35253, different approximation formulas are applied depending on the crystal grain size of the object to be measured, and there is a problem that the measurement accuracy may be significantly deteriorated. An object of the present invention is to provide a non-destructive and highly accurate crystal grain size measuring method using ultrasonic waves in order to solve the above-mentioned problems of the conventional technology.
【０００８】[0008]
【課題を解決するための手段】本発明は、被測定体内に
広帯域超音波パルスを伝播させ、その反射パルスを周波
数解析して広範な周波数ｆに対する超音波減衰定数αを
求め、ｄ（log α) ／ｄ（log ｆ) の値が3.5 以上でか
つ4.5 以下になるときのαと、被測定体に固有の定数ａ
を用いて、下記式 α＝ａ・Ｄ3 ・ｆ4 から結晶粒度Ｄを算出することを特徴とする結晶粒度測
定方法である。According to the present invention, a broadband ultrasonic pulse is propagated in a body to be measured, and the reflected pulse is subjected to frequency analysis to obtain an ultrasonic attenuation constant α for a wide range of frequencies f, and d (log α A) when the value of / d (log f) is equal to or more than 3.5 and equal to or less than 4.5, and a constant a specific to the object to be measured.
Is used to calculate the crystal grain size D from the following equation α = a · D 3 · f 4 .
【０００９】[0009]
【作 用】本発明者らが、上記課題を解決するために鋭
意実験を重ねて調査したところ、超音波の減衰定数αは
超音波周波数ｆの整数乗に比例するとは限らず、被測定
体によりあるいは測定周波数範囲により、たとえばｆ
3.1 に比例したり、ｆ4.4 に比例したりすることを見出
した。[Operation] The inventors of the present invention have conducted intensive experiments to solve the above problems, and found that the attenuation constant α of the ultrasonic wave is not always proportional to the integral power of the ultrasonic frequency f. Or by the measured frequency range, for example f
It was found to be proportional to 3.1 and proportional to f 4.4 .
【００１０】さらに、本発明者らが鋭意検討したとこ
ろ、結晶粒度の測定精度はレイリー散乱領域を充たす
α、すなわち周波数ｆのほぼ４乗に比例するαだけを用
いて、前出(1) 式すなわちα＝ａ・Ｄ3 ・ｆ4 により求
めることにより、格段に向上することがわかった。ま
た、被測定体あるいは測定条件によっては、αがｆの４
乗に比例する領域がない場合も生じるが、この場合でも
αがｆの3.5 乗以上4.5 乗以下に比例するような値を用
いて(1) 式により計算するようにすれば、高精度で結晶
粒度Ｄが求められることを確認した。Further, the present inventors have made intensive studies and found that the measurement accuracy of the crystal grain size was determined by using only α which satisfies the Rayleigh scattering region, that is, α which is approximately proportional to the fourth power of the frequency f. That is, it was found that the value was significantly improved by obtaining α = a · D 3 · f 4 . Further, depending on the object to be measured or the measurement conditions, α is 4 of f.
Although there is a case where there is no area proportional to the power, even in this case, if α is proportional to f to the 3.5th power to 4.5th power, it is possible to obtain a crystal with high accuracy by calculating it using the equation (1). It was confirmed that the particle size D was required.
【００１１】本発明は、上記の知見に基づいてなされた
ものであり、まず広帯域超音波パルスを用いてその反射
エコーを周波数解析することにより、細かいピッチで広
範な周波数ｆにおける減衰定数αのデータを得る。つぎ
に、αがｆの何乗に比例するかを判断するために、冪指
数Ｎが Ｎ＝ｄ（log α) ／ｄ（log ｆ) ……………(5) なる値を各周波数ｆに対して計算する。ここで、Ｎの値
はα＝Ｋ・ｆN としたときに、 log α＝log Ｋ＋Ｎ・log ｆ ……………(6) となることからわかるように、αがｆの何乗に比例する
かを表している。The present invention has been made based on the above findings. First, by analyzing the frequency of the reflected echo using a broadband ultrasonic pulse, the data of the attenuation constant α in a wide range of frequencies f at a fine pitch is obtained. Get. Next, in order to determine which power of α is proportional to f, the exponent N is calculated as follows: N = d (log α) / d (log f) (5) Calculate against Here, assuming that the value of N is α = K · f N , log α = log K + N · log f (6) As can be seen from equation (6), α is proportional to the power of f. To do.
【００１２】１つあるいは狭い範囲の周波数ｆに対して
αを測定しただけでは、冪指数Ｎの取り得る範囲 3.5 ≦Ｎ≦4.5 ……………(7) を充たすαが存在しない可能性があるので、広帯域超音
波パルスを用いてその反射エコーを周波数解析し、広範
な周波数ｆにおける減衰定数αを求めるのが有効であ
る。If α is measured only for one or a narrow range of frequencies f, there is a possibility that there is no α satisfying the range of the exponent N, 3.5 ≦ N ≦ 4.5 (7). Therefore, it is effective to perform frequency analysis of the reflected echo using a broadband ultrasonic pulse to obtain an attenuation constant α over a wide range of frequencies f.
【００１３】[0013]
【実施例】以下に、本発明に係る方法を種々の結晶粒度
を有する鋼板に適用した実施例について、図面を参照し
て説明する。図１は、本発明に用いられる測定装置の一
例を示した模式図である。図において、１は測定される
鋼板、２は広帯域超音波探触子、３は広帯域超音波探触
子２に取付けた水柱ノズル、４は超音波送信器、５は超
音波受信器、６はＡ／Ｄ変換器、７はコンピュータなど
の演算装置である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments in which the method according to the present invention is applied to steel plates having various grain sizes will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a measuring device used in the present invention. In the figure, 1 is a steel plate to be measured, 2 is a broadband ultrasonic probe, 3 is a water column nozzle attached to the wideband ultrasonic probe 2, 4 is an ultrasonic transmitter, 5 is an ultrasonic receiver, 6 is The A / D converter 7 is an arithmetic device such as a computer.
【００１４】超音波送信器４で励起されたパルスを広帯
域超音波探触子２から水柱ノズル３の水柱３ａを介して
鋼板１内に入射し、鋼板１からの多重底面エコーを広帯
域超音波探触子２を介して超音波受信器５で受信・増幅
し、Ａ／Ｄ変換器６でデジタル値に変換した後、演算装
置７に入力する。この演算装置７において、入力された
多重底面エコーを、図２に示すような手順で演算処理を
行って、結晶粒度Ｄを求める。 鋼板１の多重底面エコーの周波数スペクトルを計算
する。 各底面エコーの周波数スペクトル差からα（ｆ）を
計算する。超音波周波数ｆと減衰定数αとの関係の一例
を図３に示した。 各周波数ｆにおいて、(5) 式を用いて冪指数Ｎを計
算する。 (7) 式を充たす周波数ｆの範囲（ｆ1 , ｆ2 ）を求
める。超音波周波数ｆと冪指数Ｎとの関係の一例を図４
に示した。 区間（ｆ1 , ｆ2 ）内のαを、ｆの４次式 α＝Ｋ・ｆ4 ……………(8) を用いて最小自乗近似する。ここで、Ｋは係数である。The pulse excited by the ultrasonic transmitter 4 is incident on the steel plate 1 from the broadband ultrasonic probe 2 through the water column 3a of the water column nozzle 3, and the multiple bottom echo from the steel plate 1 is detected by the broadband ultrasonic probe. The signal is received and amplified by the ultrasonic receiver 5 via the probe 2, converted into a digital value by the A / D converter 6, and then input to the arithmetic unit 7. In the arithmetic unit 7, the input multiple bottom echo is subjected to arithmetic processing according to the procedure shown in FIG. The frequency spectrum of the multiple bottom surface echo of the steel plate 1 is calculated. Α (f) is calculated from the frequency spectrum difference of each bottom echo. FIG. 3 shows an example of the relationship between the ultrasonic frequency f and the attenuation constant α. At each frequency f, the exponent N is calculated using the equation (5). The range (f 1 , f 2 ) of the frequency f that satisfies the expression (7) is obtained. FIG. 4 shows an example of the relationship between the ultrasonic frequency f and the exponent N.
It was shown to. Α in the section (f 1 , f 2 ) is least-squares-approximated using the quartic expression of f, α = K · f 4 (8). Here, K is a coefficient.
【００１５】なお、減衰定数αを求める際、必要に応じ
て超音波の拡散損失および透過反射損失の影響を補正す
るのが望ましい。 で求まったＫを用いて、前出(1) 式の関係から得
られた下記(9) 式によって結晶粒度Ｄを求める。 Ｄ＝3 √（Ｋ／ａ） ……………(9) なお、被測定体に固有の定数ａとして、ここでは1.61×
10-9〔（dB/cm)(MHz ) -4 (μm)-3〕なる値を用いた。When determining the damping constant α,
To correct the effects of ultrasonic diffusion loss and transmission reflection loss.
Is desirable. Using the K found in
The crystal grain size D is determined by the following equation (9). D =Three√ (K / a) (9) Here, a constant a unique to the measured object is 1.61 × here.
Ten-9[(DB / cm) (MHz) -Four (μm)-3] Was used.
【００１６】本発明法を用いて10枚の鋼板の結晶粒度を
測定した結果を表１に示した。なお、比較のために、破
壊検査によるものを破壊測定値とし、また(3) 式を利用
した従来法を従来例として、さらに本発明法と同様の方
法ではあるが、冪指数Ｎの範囲を3.0 〜5.0 とした領域
のデータを用いた場合を比較例としてそれぞれ表１に併
せて示した。Table 1 shows the results of measuring the grain size of ten steel sheets using the method of the present invention. For comparison, a value obtained by a destructive inspection is used as a measured value of destruction, and a conventional method using equation (3) is used as a conventional example. Table 1 also shows the case where the data in the range of 3.0 to 5.0 was used as a comparative example.
【００１７】[0017]
【表１】 [Table 1]
【００１８】この表から明らかなように、本発明例は、
破壊試験による破壊測定値の結果とよく一致しているこ
とがわかる。一方、従来例および比較例はいずれも誤差
が大きくなることが実証されている。なお、上記した実
施例における超音波探触子は鋼板に非接触とした非接触
方式について説明したが、本発明はこれに限るものでは
なく、超音波探触子を鋼板に接触させる方式、あるいは
超音波探触子と鋼板との間に水を充満させる方式であっ
ても差し支えない。また、超音波探触子の型式としては
送受信兼用したものでなくともよく、送信用と受信用と
を別個にしたものを用いてもよい。As is clear from this table, the present invention example
It can be seen that the results agree well with the results of the destruction measurement values by the destruction test. On the other hand, it has been proved that both the conventional example and the comparative example have a large error. Although the ultrasonic probe in the above-described embodiment has been described as a non-contact type in which the ultrasonic probe is not in contact with the steel plate, the present invention is not limited thereto, and a method in which the ultrasonic probe is brought into contact with the steel plate, or A method in which water is filled between the ultrasonic probe and the steel plate may be used. Also, the type of the ultrasonic probe need not be used for both transmission and reception, and may be one for transmission and reception separately.
【００１９】さらに、反射パルスの周波数解析処理を行
う手段は、コンピュータで計算する方法以外に周波数解
析器を用いるようにしてもよい。また、上記実施例は鋼
板の結晶粒度測定を対象にして説明したが、本発明はこ
れに限るものではなく、たとえばアルミやチタンなどの
他の金属、あるいはセラミックなどの非金属材料にも適
用し得ることはいうまでもない。Further, the means for performing the frequency analysis processing of the reflected pulse may use a frequency analyzer other than the method of calculating with a computer. Although the above embodiments have been described with reference to the measurement of the grain size of a steel sheet, the present invention is not limited to this, and may be applied to other metals such as aluminum and titanium, or non-metal materials such as ceramics. It goes without saying that you get it.
【００２０】[0020]
【発明の効果】以上説明したように、本発明によれば、
広帯域超音波パルスの反射波を周波数解析することによ
り、広範な周波数ｆに対する超音波減衰定数αを得るこ
とができ、周波数ｆの3.5 乗以上でかつ4.5 乗以下に比
例するαのみを対象にして、α＝ａ・Ｄ3 ・ｆ4 によ
り、結晶粒径Ｄを算出するようにしたので、自動的にレ
イリー散乱領域を充たす周波数領域で測定をしたことと
等価になり、これによって結晶粒度を非破壊の手段で高
精度に求めることが可能である。As described above, according to the present invention,
By frequency analysis of the reflected wave of the broadband ultrasonic pulse, it is possible to obtain an ultrasonic attenuation constant α for a wide range of frequencies f, and only for α that is proportional to the frequency f of 3.5 or more and 4.5 or less. , Α = a · D 3 · f 4 , the crystal grain size D is calculated, which is equivalent to automatically measuring in the frequency region that satisfies the Rayleigh scattering region. It can be obtained with high precision by means of destruction.
【図１】本発明に用いられる測定装置の一例を示した模
式図である。FIG. 1 is a schematic view showing an example of a measuring device used in the present invention.
【図２】本発明に演算装置における演算処理の手順を示
すフローチャートである。FIG. 2 is a flowchart illustrating a procedure of a calculation process in a calculation device according to the present invention.
【図３】超音波周波数ｆと減衰定数αとの関係を示す特
性図である。FIG. 3 is a characteristic diagram showing a relationship between an ultrasonic frequency f and an attenuation constant α.
【図４】超音波周波数ｆと指数Ｎとの関係を示す特性図
である。FIG. 4 is a characteristic diagram showing a relationship between an ultrasonic frequency f and an index N.
１ 鋼板 ２ 広帯域超音波探触子 ３ 水柱ノズル ４ 超音波送信器 ５ 超音波受信器 ６ Ａ／Ｄ変換器 ７ 演算装置 DESCRIPTION OF SYMBOLS 1 Steel plate 2 Broadband ultrasonic probe 3 Water column nozzle 4 Ultrasonic transmitter 5 Ultrasonic receiver 6 A / D converter 7 Arithmetic unit
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭53−126991（ＪＰ，Ａ) 特開 昭60−35253（ＪＰ，Ａ) 特開 昭58−160865（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 29/00 - 29/28 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-126991 (JP, A) JP-A-60-35253 (JP, A) JP-A-58-160865 (JP, A) (58) Field (Int. Cl. 7 , DB name) G01N 29/00-29/28
Claims (1)
播させ、その反射パルスを周波数解析して広範な周波数
ｆに対する超音波減衰定数αを求め、ｄ（log α) ／ｄ
（log ｆ) の値が3.5 以上でかつ4.5 以下になるときの
αと、被測定体に固有の定数ａを用いて、下記式 α＝ａ・Ｄ3 ・ｆ4 から結晶粒度Ｄを算出することを特徴とする結晶粒度測
定方法。1. A broadband ultrasonic pulse is propagated in a measured body, and the reflected pulse is subjected to frequency analysis to obtain an ultrasonic attenuation constant α for a wide range of frequencies f, and d (log α) / d
Using α when the value of (log f) is 3.5 or more and 4.5 or less and a constant a specific to the measured object, the crystal grain size D is calculated from the following equation α = a · D 3 · f 4 A method for measuring crystal grain size, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05043127A JP3140244B2 (en) | 1993-03-04 | 1993-03-04 | Grain size measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05043127A JP3140244B2 (en) | 1993-03-04 | 1993-03-04 | Grain size measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06258299A JPH06258299A (en) | 1994-09-16 |
| JP3140244B2 true JP3140244B2 (en) | 2001-03-05 |
Family
ID=12655184
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05043127A Expired - Fee Related JP3140244B2 (en) | 1993-03-04 | 1993-03-04 | Grain size measurement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3140244B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004271348A (en) * | 2003-03-10 | 2004-09-30 | Univ Nihon | Instrument for measuring concentration of fine particles |
| RU2650713C1 (en) * | 2017-02-06 | 2018-04-17 | Алексей Викторович Пигарев | Method of measuring small factors of optical absorption of nonlinear optic crystals |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100797281B1 (en) * | 1999-12-28 | 2008-01-23 | 주식회사 포스코 | A Nondestructive Measurement Method for Grain Size of Ferrite Crystal by Ultrasonic Method |
| JP2008545123A (en) * | 2005-07-06 | 2008-12-11 | ナショナル・リサーチ・カウンシル・オブ・カナダ | Method and system for determining material properties using ultrasonic attenuation |
| CN103645248B (en) * | 2013-12-18 | 2015-09-30 | 中南大学 | A kind of high-temperature alloy grain size evaluation method based on ultrasonic phase velocity |
| JP7072432B2 (en) * | 2018-04-11 | 2022-05-20 | 株式会社アーステクニカ | Non-destructive inspection method for high manganese cast steel |
-
1993
- 1993-03-04 JP JP05043127A patent/JP3140244B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004271348A (en) * | 2003-03-10 | 2004-09-30 | Univ Nihon | Instrument for measuring concentration of fine particles |
| RU2650713C1 (en) * | 2017-02-06 | 2018-04-17 | Алексей Викторович Пигарев | Method of measuring small factors of optical absorption of nonlinear optic crystals |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06258299A (en) | 1994-09-16 |
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