JPH071268B2 - Quantitative nondestructive identification method for carbon content in stainless steel - Google Patents
Quantitative nondestructive identification method for carbon content in stainless steelInfo
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- JPH071268B2 JPH071268B2 JP61161279A JP16127986A JPH071268B2 JP H071268 B2 JPH071268 B2 JP H071268B2 JP 61161279 A JP61161279 A JP 61161279A JP 16127986 A JP16127986 A JP 16127986A JP H071268 B2 JPH071268 B2 JP H071268B2
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- carbon content
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- stainless steel
- carbide
- carbon
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Description
【発明の詳細な説明】 〈産業上の利用分野〉 本発明は，ステンレス鋼中の炭素含有量を定量的かつ非
破壊的に鑑別する方法に関する。TECHNICAL FIELD The present invention relates to a method for quantitatively and nondestructively discriminating a carbon content in stainless steel.
〈従来の技術〉 従来鉄鋼中の含有炭素を定量する方法として最も信頼し
得るものは重量法，容量法及び比色法等の化学的分析法
とされている。しかしながらその実施に当っては専門的
な知識と特殊な装置を用いて而も極めて分析に長時間を
必要とするのみならず，被検体を非破壊的に分析し得な
いという重大な欠点がある。またこの外に迅速簡易法と
して応用価値大なりと思推されるものに磁気法，電気抵
抗法，接触起電力法あるいは火花検査法等があるが，こ
れらは何れも物理的現象を測定して判定するものである
から誤差の原因が多く，従ってこれらの方法単独で正確
な定量を行うことは極めて困難であった。<Prior art> Conventionally, the most reliable method for quantifying carbon content in iron and steel is chemical analysis such as gravimetric method, volumetric method and colorimetric method. However, in its implementation, not only does it require a very long time for analysis using specialized knowledge and a special device, but there is a serious drawback in that the subject cannot be analyzed nondestructively. . In addition to these, there are magnetic methods, electric resistance methods, contact electromotive force methods, spark inspection methods, etc. that are thought to have great application value as quick and simple methods, but these all measure physical phenomena. Since it is a judgment, there are many causes of error, and it is extremely difficult to perform accurate quantification by these methods alone.
〈発明が解決しようとする問題点〉 本発明者は叙上従来法の欠点に鑑みて，さきに特許第41
8846号「鉄鋼中炭素簡易定量法」を発明し，非破壊的に
鉄鋼中の含有炭素量を簡易に定量分析し得る方法を提案
している。この方法は，鉄鋼材料被検体の表面を直接陽
極とし，これと電導性物質よりなる陰極との間に硝酸又
は硝酸塩等の溶液を湿潤させた滞水性物質を介して電界
反応を行わせ，陽極より溶出する黄色乃至黒褐色のニト
ロ化合物，例えばC17H22(NO2)2O25を該滞水性物質の陽
極側表面に化生せしめ，その色調を既知の標準色又は標
準試料等と比色することにより，鉄鋼材料被検体中に含
有する炭素量を極めて簡易なる装置及び操作をもって迅
速，確実且つ被検体を何ら傷つけることなく容易に定量
し得ることを特徴とする。<Problems to be Solved by the Invention> In view of the drawbacks of the conventional method, the present inventor has previously described Patent No. 41.
Invented No. 8846 "Simplified quantitative determination of carbon in iron and steel" and proposed a method that enables nondestructive and simple quantitative analysis of carbon content in steel. In this method, the surface of a steel material specimen is directly used as an anode, and an electric field reaction is performed between the cathode and the cathode made of a conductive substance through a water-holding substance moistened with a solution of nitric acid or a nitrate. A more eluting yellow or black-brown nitro compound, such as C 17 H 22 (NO 2 ) 2 O 25, is metamorphosed on the surface of the water-holding substance on the anode side, and its color tone is compared with a known standard color or standard sample. By doing so, the amount of carbon contained in the steel material test object can be quantified quickly, reliably and easily without damaging the test object with an extremely simple device and operation.
この方法による判定精度は,0.1％以上の炭素量を±0.05
％の僅少な誤差で肉眼的に鑑定し得，更に光学手法を併
用すれば更に高精度な判定を期待し得るものであるが，
ステンレス鋼の如く,0.1％以下の含有炭素量の鋼種では
含有炭素による発色濃度が低くなるため，含有Crによる
発色濃度に打消されて鑑別の精度が低下する惧れがあっ
た。更に又これを精度よくなし得る非破壊的簡易な定量
分析技法は未だ開発されておらず，業界においてその出
現が希求されている現状である。The judgment accuracy by this method is ± 0.05% for carbon contents of 0.1% or more.
It is possible to make a visual inspection with a small error of%, and if an optical method is used in combination, more accurate judgment can be expected.
In the case of steel grades with a carbon content of 0.1% or less, such as stainless steel, the color density due to the carbon content is low, so there is a risk that the color density due to the Cr content will be canceled out and the accuracy of discrimination will be reduced. Furthermore, a nondestructive and simple quantitative analysis technique that can do this with high accuracy has not yet been developed, and its appearance is demanded in the industry.
本発明は前述の従来分析法の欠点を解決することを目的
として提案するもので，炭素含有量が0.1％以下で，か
つその含有量が微妙に相違する近似化学成分のステンレ
ス鋼材種をも簡易にして非破壊的に鑑別し得る分析方法
を提供せんとするものである。The present invention is proposed for the purpose of solving the above-mentioned drawbacks of the conventional analysis method, and is simple even for stainless steel grades having an approximate chemical composition in which the carbon content is 0.1% or less and the content is subtly different. It is intended to provide an analytical method that can be nondestructively distinguished.
〈問題点を解決するための手段） ステンレス鋼の炭素含有量を非破壊かつ定量的に鑑別す
るにあたり，予め被検体を適宜の加熱手段，例えばバー
ナや溶接，溶断用トーチによる加熱手段，あるいは電磁
誘導による加熱手段等により該被検体を500〜800℃に所
定時間加熱して，その結晶粒界にM23C6（但し,MはCr,Ni
等を示す）よりなるクローム炭化物を析出させたのち，
上記被検体の該炭化物を化成した部位における残存Cr,N
i等の含有量をＸ線回折装置や電解式定量分析法等任意
の非破壊的分析法により求め，これらの数値と仝分析法
により求めた上記ステンレス鋼の合金成分としてのCrま
たはNi等の含有量との差から上記クローム炭化物の化成
に消費されたCrまたはNiの量を求め，かつ，上記分子式
M23C6に基づき当該炭化物を化成するに関与した炭素の
含有量を算出し，もって上記被検体の含有炭素量とする
ことを特徴とするステンレス鋼中の炭素含有量の定量的
非破壊鑑別法を要旨とし，当該法をもって前記問題点を
解決するための手段とした。<Means for solving the problem> In order to nondestructively and quantitatively distinguish the carbon content of stainless steel, the specimen is previously heated by an appropriate heating means such as a burner, welding, a heating torch for fusing, or an electromagnetic wave. The specimen is heated to 500 to 800 ° C. for a predetermined time by a heating means such as induction, and M 23 C 6 (where M is Cr, Ni
And the like) are deposited, and
Residual Cr, N at the site where the carbide of the subject was formed
The content of i, etc. was obtained by an arbitrary nondestructive analysis method such as an X-ray diffractometer or electrolytic quantitative analysis method, and these values and Cr or Ni, etc. Calculate the amount of Cr or Ni consumed in the formation of the above chromium carbide from the difference with the content, and
Quantitative nondestructive discrimination of carbon content in stainless steel, characterized in that the content of carbon involved in the formation of the carbide is calculated based on M 23 C 6 and is used as the content of carbon in the above-mentioned specimen. The law is the gist, and the law is the means for solving the above problems.
ここで，上記電解式定量分析法とは，本発明者がさきに
特開昭61−251765号をもって提案した「電解式非破壊的
金属材料簡易定量分析法」に係り，その要旨とするとこ
ろは，電池若しくは直流電源の陽極子を直接に，使用電
解液に腐食され難い物質よりなる陰極子を被検金属体を
溶解するが如き電解液を含浸せる滞水性物質を介してそ
れぞれ被検金属体表面に接触せしめて電気回路を形成せ
しめると共に，該回路に電圧調整器と電圧計とを介装
し，電圧及び通電時間を規定して電解反応を行わせ，そ
の際陽極より溶出する含有金属の発生機酸素による酸化
イオンの帯水性物質陽極側表面に於ける呈色の有無の限
界電圧を求め，一方予め各金属材種について通電時間を
一定として求めた発色し得る限界電圧と該金属材種中の
含有金属の含有量との関係とを比較することにより非破
壊的にしかも簡易に定量分析する方法であって，呈色す
るかしないかという明瞭な判定のもとに求めたその限界
電圧は，金属含有量と極めて定量的な関係にあることを
見出し，簡易にしてしかも高精度な分析を可能としたも
ので，合金鋼中Cr,Ni等の含有量を定量することができ
る。Here, the electrolytic quantitative analysis method relates to the “electrolytic nondestructive metallic material simple quantitative analysis method” proposed by the present inventor in Japanese Patent Laid-Open No. 61-251765, and its gist is , The anode of a battery or a DC power source directly, the cathode of a substance that is not easily corroded by the electrolyte used, dissolves the metal to be inspected An electric circuit is formed by contacting the surface, and a voltage regulator and a voltmeter are provided in the circuit to regulate the voltage and the energization time to carry out an electrolytic reaction. The threshold voltage for the presence or absence of coloration on the surface of the anode side of the hydration material of the oxidative ion due to the generator oxygen was determined, while the limit voltage and the metal material type that could be developed were obtained for each metal material type with a constant energization time. With the content of contained metal in It is a non-destructive and simple method for quantitative analysis by comparing with a metallizer, and the limiting voltage obtained based on a clear judgment as to whether or not a color develops is extremely quantitative with the metal content. It is possible to quantify the content of Cr, Ni, etc. in the alloy steel by discovering that there is a relationship, and enabling simple and highly accurate analysis.
さて，一般に，ステンレス鋼を500〜800℃に加熱，徐冷
すると結晶粒界にクローム炭化物が析出し，粒界腐食が
生じる。この現象を生じさせることを鋭敏化熱処理とい
うが，被検体の炭素含有量が0.05％程度以上の場合は，
約700℃附近に約１分位加熱するだけで結晶粒界にクロ
ーム炭化物を析出することが認められており，同様に，
炭素含有量が0.027％程度以下では約５分位の加熱時間
で炭化物の析出が認められる。また加熱温度の低下に応
じて該炭化物の析出には長時間の加熱を要する傾向が認
められるが,500℃を下廻る温度，及び800℃を超える温
度では炭化物の析出は殆んど生じない。而して，このク
ローム炭化物はM23C6で表示されるもので,MはCrのほか
にNi,さらに若干のFeも含まれる。Generally, when stainless steel is heated to 500 to 800 ° C and gradually cooled, chrome carbide precipitates at the grain boundaries and intergranular corrosion occurs. This phenomenon is called sensitization heat treatment, but when the carbon content of the specimen is about 0.05% or more,
It has been confirmed that chrome carbide is precipitated at the grain boundaries only by heating for about 1 minute at about 700 ° C.
When the carbon content is about 0.027% or less, the precipitation of carbides is recognized in the heating time of about 5 minutes. Although it tends to be necessary to heat the carbide for a long time depending on the decrease of the heating temperature, the precipitation of the carbide hardly occurs at a temperature lower than 500 ° C and a temperature higher than 800 ° C. And Thus, the chrome carbide intended to be displayed by the M 23 C 6, M is Ni in addition to Cr, also it includes some more Fe.
このような炭化物の炭素成分量は被検体の炭素含有量と
比例的な関係があり，従ってＭの成分量が測定できれ
ば，M23C6式から炭素量が算出可能であり，この炭素量
から被検体の含有炭素量を推定することが可能となる。
而して，炭化物を構成するＭの成分量の測定は，被検体
の鋭敏化熱処理によって結晶粒界に析出した炭化物が被
検体のＭ即ちCr,Ni等を消費して化成したものであるか
ら，該炭化物を析出した部位の被検体残存Cr,Ni等と，
当該鋭敏化熱処理を施していない被検体の合金成分とし
ての含有Cr,Ni量とを夫々測定し，両者の差を算出すれ
ば，該炭化物のＭ値（Cr,Ni等の含有量）を知ることが
できる。この被検体のCr,Ni等の含有量の測定は，前記
した電解式定量分析法やＸ線回折装置等任意の非破壊的
分析法が採用できる。The carbon content of such a carbide has a proportional relationship with the carbon content of the test object. Therefore, if the content of M can be measured, the carbon content can be calculated from the M 23 C 6 formula. It is possible to estimate the carbon content of the subject.
Thus, the amount of the M component that constitutes the carbide is measured because the carbide precipitated on the grain boundaries by the sensitization heat treatment of the subject consumes M of the subject, that is, Cr, Ni, etc. , The residual Cr, Ni, etc. of the specimen at the site where the carbide is deposited,
The M value (contents of Cr, Ni, etc.) of the carbide can be known by measuring the amounts of Cr and Ni contained as alloy components of the specimen not subjected to the sensitization heat treatment and calculating the difference between them. be able to. The content of Cr, Ni, etc. in the sample can be measured by any nondestructive analysis method such as the electrolytic quantitative analysis method and the X-ray diffraction apparatus described above.
尚，化学成分中炭素の含有量が僅かに相違し，他の成分
が同一かもしくは殆んど同一の極類似成分のステンレス
鋼種，例えば,SUS 304とSUS 304LあるいはSUS 316とSUS
316Lとの判別も，本発明方法によって夫々の被検体中
の含有炭素量を分析し，その炭素量の比較によって容易
に両者を判別することが可能である。The carbon content in the chemical composition is slightly different, and the other components are the same or almost the same as the very similar components of stainless steel such as SUS 304 and SUS 304L or SUS 316 and SUS.
In the determination of 316L, it is also possible to easily determine the two by analyzing the carbon content in each subject by the method of the present invention and comparing the carbon content.
尚又，本発明方法実施にあたり，被検体に溶接個処また
は溶断個処があれば，その熱影響部は，鋭敏化熱処理と
同等な熱処理を受けており，その結晶粒界に炭化物を析
出していることが明らかなため，本発明における被検体
の事前加熱処理と見做して，前記溶接，溶断個処の熱影
響部を利用することもできるので，本発明に謂う適宜の
加熱手段に含むものとする。Further, in carrying out the method of the present invention, if the specimen has a welding part or a fusing part, the heat-affected zone has undergone heat treatment equivalent to the sensitizing heat treatment, and carbides are precipitated at the grain boundaries. Since it is clear that the heat-affected zone of the welding or fusing point can be used as the pre-heat treatment of the specimen in the present invention, it can be used as an appropriate heating means in the present invention. Shall be included.
〈実施例〉 各種規格のステンレス鋼の被検体を夫々750℃に３分間
加熱保持後,1/10規定の硫酸を電解液とし前記電解式定
量分析法に準拠してシフェニールカルバジドを発色試薬
としてCrの含有量を定量分析し，被検体の加熱前後（又
は加熱した部分としない部分）のCr含有量を夫々求めた
のち，その差と被検体の炭素含有量との関係を求めた。〈Examples〉 Samples of various types of stainless steel were heated and held at 750 ° C for 3 minutes, and 1/10 normal sulfuric acid was used as an electrolytic solution to develop cyphenyl carbazide as a color reagent in accordance with the electrolytic quantitative analysis method. As a result, the Cr content was quantitatively analyzed, the Cr contents before and after heating (or the heated portion and the non-heated portion) of the specimen were respectively determined, and then the relationship between the difference and the carbon content of the specimen was determined.
その関係グラフを第１図に示す。The relationship graph is shown in FIG.
同グラフに見られるように，被検体加熱前後のCr分析値
の差（％）と被検体の炭素含有量とは比例関係にあり，
該Cr分析値の差を求めることにより，被検体の炭素含有
量を定量的に推定することができる。As can be seen in the graph, the difference (%) in the Cr analysis values before and after heating the sample is proportional to the carbon content of the sample,
By obtaining the difference between the Cr analysis values, the carbon content of the subject can be quantitatively estimated.
〈発明の効果〉 以上要するに本発明方法によれば，従来公知の分析法に
よってなし得なかった非破壊的かつ定量的ステンレス鋼
の含有炭素量の分析を極めて簡易に且つ高精度で実現し
得るのみならず，従来判別が極めて困難とされていたSU
S 304とSUS 304L,あるいはSUS 316とSUS 316Lの如き化
学成分の極類似ステンレス鋼種を容易に判別することが
可能となり，業界の要請を満足せしめ得て甚だ有益であ
る。<Effects of the Invention> In short, according to the method of the present invention, the nondestructive and quantitative analysis of the carbon content of stainless steel, which could not be achieved by the conventionally known analysis method, can be realized very simply and highly accurately. Therefore, the SU, which was previously extremely difficult to discriminate
This makes it possible to easily distinguish very similar stainless steel grades with chemical components such as S 304 and SUS 304L, or SUS 316 and SUS 316L, which is extremely beneficial because it can satisfy the demands of the industry.
第１図は，各種規格ステンレス鋼被検体の加熱前後にお
ける含有Cr分析値の差（％）と該被検体の炭素含有量と
の関係を示すグラフ。FIG. 1 is a graph showing the relationship between the difference (%) in the analysis value of contained Cr before and after heating of various standard stainless steel specimens and the carbon content of the specimens.
Claims (1)
量的に鑑別するにあたり，予め被検体を適宜の加熱手段
により該被検体の結晶粒界に炭化物を析出する温度（50
0〜800℃）に所定時間加熱してその結晶粒界にM23C
6（但し,MはCr,Ni等を示す）よりなるクローム炭化物を
析出させたのち，上記被検体の該炭化物を化成した部位
における残存CrまたはNi等の含有量を電解式定量分析法
等任意の非破壊的分析法により求め，これらの数値と仝
分析法により求めた上記ステンレス鋼の合金成分として
のCrまたはNi等の含有量との差から上記クローム炭化物
の化成に消費されたCrまたはNiの量を求め，かつ，上記
分子式M23C6に基づき当該炭化物を化成するに関与した
炭素の含有量を算出し，もって上記被検体の含有炭素量
を定量的に鑑別することを特徴とするステンレス鋼中の
炭素含有量の定量的非破壊鑑別法。1. When non-destructively and quantitatively distinguishing the carbon content of stainless steel, the temperature (50) at which carbide is precipitated in the grain boundaries of the specimen in advance by an appropriate heating means.
(0-800 ° C) for a specified time and M 23 C at the grain boundaries.
After depositing a chromium carbide consisting of 6 (M is Cr, Ni, etc.), the content of residual Cr, Ni, etc. at the site where the carbide was formed in the above-mentioned sample was determined by electrolytic quantitative analysis, etc. The non-destructive analysis method of Cr and Ni consumed in the formation of the above chromium carbide was calculated from the difference between these values and the content of Cr or Ni, etc. as an alloying component of the above stainless steel obtained by the above analysis method. Is obtained, and the content of carbon involved in the formation of the carbide is calculated based on the molecular formula M 23 C 6 to quantitatively discriminate the carbon content of the analyte. Quantitative nondestructive identification method of carbon content in stainless steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61161279A JPH071268B2 (en) | 1986-07-08 | 1986-07-08 | Quantitative nondestructive identification method for carbon content in stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61161279A JPH071268B2 (en) | 1986-07-08 | 1986-07-08 | Quantitative nondestructive identification method for carbon content in stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6316264A JPS6316264A (en) | 1988-01-23 |
| JPH071268B2 true JPH071268B2 (en) | 1995-01-11 |
Family
ID=15732086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61161279A Expired - Lifetime JPH071268B2 (en) | 1986-07-08 | 1986-07-08 | Quantitative nondestructive identification method for carbon content in stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH071268B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5740624B2 (en) * | 2012-08-16 | 2015-06-24 | 株式会社ケミカル山本 | Simple nondestructive discrimination method between stainless steel L and non-L materials |
| CN103207194B (en) * | 2013-01-29 | 2015-05-13 | 武汉大学 | Method for determining content of element W in matrix after long-term operation of T/P92 steel |
| JP6808198B2 (en) * | 2018-02-14 | 2021-01-06 | 三菱重工業株式会社 | Damage condition determination device, damage condition determination method, program |
-
1986
- 1986-07-08 JP JP61161279A patent/JPH071268B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6316264A (en) | 1988-01-23 |
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