JPH0523386B2 - - Google Patents
Info
- Publication number
- JPH0523386B2 JPH0523386B2 JP60093352A JP9335285A JPH0523386B2 JP H0523386 B2 JPH0523386 B2 JP H0523386B2 JP 60093352 A JP60093352 A JP 60093352A JP 9335285 A JP9335285 A JP 9335285A JP H0523386 B2 JPH0523386 B2 JP H0523386B2
- Authority
- JP
- Japan
- Prior art keywords
- potential
- specimen
- electrode
- passivation
- stainless steel
- 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
Links
- 238000002161 passivation Methods 0.000 claims description 18
- 239000000463 material Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 229910001220 stainless steel Inorganic materials 0.000 claims description 9
- 239000010935 stainless steel Substances 0.000 claims description 9
- 230000000694 effects Effects 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 6
- 239000003792 electrolyte Substances 0.000 claims description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 20
- 239000000243 solution Substances 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 2
- 229910001651 emery Inorganic materials 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- 230000002269 spontaneous effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000010963 304 stainless steel Substances 0.000 description 1
- 208000010412 Glaucoma Diseases 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910000589 SAE 304 stainless steel Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000011005 laboratory method Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000002688 persistence Effects 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Sampling And Sample Adjustment (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Description
【発明の詳細な説明】
本発明は、金属表面の不働態化の有無、ならび
にその程度を簡易に測定する方法に係り、ステン
レス鋼に適用して特に効果的なものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for simply measuring the presence or absence of passivation on a metal surface and its degree, and is particularly effective when applied to stainless steel.
従来、一部の金属材料就中ステンレス鋼は表面
の耐食性を向上させるために製造工程に於て不働
態化を考慮した表面処理が施されているが、その
二次加工に際しては切削、研摩などの機械的研削
や、酸洗、脱脂、洗篠などの化学的処理を施すこ
とにより該不働態化処理表面は活性化してしまい
腐食や発錆をおこし易くなることは公知の事実で
ある。 Conventionally, some metal materials, particularly stainless steel, have been subjected to surface treatments that consider passivation during the manufacturing process in order to improve their surface corrosion resistance, but their secondary processing requires cutting, polishing, etc. It is a well-known fact that by mechanical grinding or chemical treatment such as pickling, degreasing, and washing, the passivated surface becomes activated and becomes susceptible to corrosion and rust.
しかし反面、ステンレス鋼にはそれ自身を清浄
な大気中にしかも長期間放置するだけでも自然に
或る程度までは不働態化する性質があるがその程
度は充分でなく、しかも長期間を必要とするた
め、ステンレス鋼製品を加工工場から使用現場へ
移動させたり、或は工場へ据付けてから運転する
までの間を安全に保守するためには、その目的や
期間に応じた適切な不動態化処理が必要とされて
きた。 However, on the other hand, stainless steel has the property of naturally becoming passivated to a certain extent if it is left in clean air for a long period of time, but this degree is not sufficient and it requires a long period of time. Therefore, in order to safely maintain stainless steel products during transport from the processing factory to the site of use, or between installation at the factory and operation, appropriate passivation is required depending on the purpose and period. processing was required.
これがために不動態化処理方法としては、硝酸
又は硝酸に重クロム酸塩、苛性ソーダに重クロム
酸塩、苛性ソーダに過マンガン酸塩を添加した各
水溶液中に、常温乃至は80℃程度まで加温した状
態で30分乃至２時間程度浸漬する方法が一般に推
奨されている。 For this reason, the passivation treatment method is to add dichromate to nitric acid, dichromate to caustic soda, or permanganate to caustic soda and heat it to room temperature or about 80℃. Generally recommended is a method of soaking for 30 minutes to 2 hours.
しかして叙上の如き活性化乃至は不働態化の程
度を判定する手段としては、従来から１規定濃度
の硫酸溶液中に於て、甘汞を一極とし、測定すべ
き被検体を一極として夫々を一つの容器に於て浸
漬した状態で該両極間に電位差計を配して自然発
生電位を測定することにより判定する方法が提案
され、試験室的な唯一の方法として採用されてい
るが、通常はビーカーを容器とし被検体もこれに
相応した大きさの試験片に制約されるため、被検
体が製品である場合やとりわけ叙上の如き不働態
化処理溶液中に浸漬出来ない製造物などについて
その不働態化効果、つまり被検体表面に生成され
た不働態化被膜のできばえ、仕上がり状態を直接
測定することは不可能であり、また実施に際して
はビーカーや多量の硫酸溶液、さらには破損し易
くて取扱いの不便な甘汞電極など特定の設備と特
殊な技術とを必要とするため現場的に実用的でな
いなどの欠点があつた。 However, as a means of determining the degree of activation or passivation as described above, conventionally, in a sulfuric acid solution of 1 normal concentration, the sample to be measured is placed at one pole, and the sample to be measured is placed at one pole. A method was proposed to determine the spontaneous potential by placing a potentiometer between the two electrodes while immersing them in a single container, and this method has been adopted as the only laboratory method. However, since the test piece is usually limited to a beaker and a test piece of a corresponding size, this is especially true when the test piece is a product, or in particular when the test piece cannot be immersed in the passivation treatment solution as mentioned above. It is impossible to directly measure the passivation effect of an object, that is, the quality and finish of the passivation film formed on the surface of the object. In addition, it requires specific equipment and special techniques, such as a glaucoma electrode that is easily damaged and inconvenient to handle, making it impractical in the field.
本発明は、前述の如き公知方法に於ける欠点を
改良するために創案されたもので、ステンレス鋼
よりなる被検体を直接一極とし、該被検体と同一
材質よりなる他の一極を活性化状態としたうえで
被検体を溶解することができる電解液を含浸させ
た紙の如き帯水性の紙葉状物質を介して該被検
体表面に接触せしめると共に、両極間に電位差計
を配してその間の自然発生電位を測定することに
より、予め求めておいた不働態化の程度と自然発
生電位との関係から金属の不働態化効果を測定す
る如くしたことを特徴とするもので、本法によれ
ば極めて簡単な装置及び操作をもつて、如何なる
形状の被検体についても非破壊的に、しかも現場
的に極めて簡易に測定することを可能としたもの
である。 The present invention was devised in order to improve the drawbacks of the known methods as described above, and involves directly using a specimen made of stainless steel as one pole, and activating another pole made of the same material as the specimen. The sample is brought into contact with the surface of the sample through a water-absorbing sheet-like material such as paper impregnated with an electrolyte capable of dissolving the sample, and a potentiometer is placed between the two electrodes. The method is characterized in that the passivation effect of the metal is measured from the relationship between the spontaneously generated potential and the degree of passivation determined in advance by measuring the spontaneously generated potential during that time. According to this method, it is possible to non-destructively measure a specimen of any shape using an extremely simple device and operation, and moreover, it is extremely easy to measure on-site.
今本発明の好ましい一実施例を図面に基づいて
説明すれば、１は完全な不働態化処理が施された
SUS 304ステンレス鋼製被検体、２は該被検体
と同一材質として選ばれたSUS304製の電極、３
は一規定濃度の硫酸溶液を含浸させた帯水性紙葉
状物質としての紙、４は電位差計、５はその一
端を電極２に、他端を電位差計４を接続した導
線、６はその一端を被検体１の任意の個所に接続
せしめ且つその他端を電位差計４に接続した導線
である。 Now, to explain one preferred embodiment of the present invention based on the drawings, 1 is completely passivated.
Object made of SUS 304 stainless steel, 2 is an electrode made of SUS 304 selected as the same material as the object, 3
is a sheet of paper impregnated with a sulfuric acid solution of a certain concentration; 4 is a potentiometer; 5 is a conductor wire with one end connected to electrode 2 and the other end connected to potentiometer 4; This is a conductive wire that is connected to an arbitrary location on the subject 1 and whose other end is connected to the potentiometer 4.
さて、このような装置において、SUS304ステ
ンレス鋼製被検体１の比較的平坦な表面を選定
し、その上に１規定濃度の硫酸溶液を電解液とし
て含浸させた紙３をあてがい、更にその上に
SUS304製電極２をエメリーペーパーを用いてそ
の表面を研磨して充分活性化したうえで重ねて電
化回路を形成させる。直ちに電位差計４の指示値
を経時的に計測し、予め材質並びにその表面の活
性化、不働態化の程度を種々変えて準備した標準
被検体を同一条件で処理したものと対比して、そ
の初期電位の数値並びに電位の持続時間を比較す
ることにより不働態化効果の判定を行なえばよ
い。 Now, in such an apparatus, a relatively flat surface of the SUS304 stainless steel specimen 1 is selected, a paper 3 impregnated with a sulfuric acid solution of 1 normal concentration as an electrolyte is placed on top of it, and then
The surface of the SUS304 electrode 2 is polished using emery paper to sufficiently activate it, and then stacked to form an electrical circuit. Immediately, the indicated value of the potentiometer 4 was measured over time, and compared with standard specimens prepared in advance with various materials and the degree of activation and passivation of the surface treated under the same conditions. The passivation effect may be determined by comparing the value of the initial potential and the duration of the potential.
而してこの場合の反応は、所定濃度の硫酸を含
浸させた紙を介してその表、裏の両面に於て
は、被検体並びに電極が硫酸溶液を電解液として
所謂る一次電池を形成することゝなるが、不働態
化被膜が強いほど耐食性があり、若しも一方の電
極も完全に不働態化しておけば同様に耐食性を示
すため、被検体の耐食被膜と同一材質よりなる電
極の耐食被膜同志とでは起電力を生じない。とこ
ろが前述の如く電極表面は予め完全に活性化され
ており、一方の被検体は完全な不働態化処理が施
されているため、該両極間の初期電位は600ｍＶ
以上の高い値を示し、経時的には該被検体１の不
働態被膜が該硫酸に浸食されて溶解するため、や
がて完全に溶解、消失するに伴なつて電位も下
り、約３分後に於てはついに零近くにまで低下し
た。 In this case, the reaction occurs through paper impregnated with sulfuric acid at a predetermined concentration, and on both the front and back sides of the paper, the specimen and the electrode form a so-called primary battery using the sulfuric acid solution as the electrolyte. Of course, the stronger the passivation film is, the more corrosion resistant it is, and if one electrode is also completely passivated, it will show corrosion resistance as well. No electromotive force is generated between corrosion-resistant coatings. However, as mentioned above, the electrode surface has been completely activated in advance, and one of the test objects has been completely passivated, so the initial potential between the two electrodes is 600 mV.
As time passes, the passive film of the specimen 1 is eroded and dissolved by the sulfuric acid, so as it completely dissolves and disappears, the potential also decreases, and after about 3 minutes, the Eventually, it dropped to near zero.
このように本願は、他の一極に被検体と同一材
質を選び、かつ活性化した状態としたことにより
測定を可能にしたもので、初期電位が高いという
ことは緻密で比較的厚い不働態化被膜が生成して
いることを示し、電位に持続性があるということ
は生成した被膜の強度、耐腐食性の大きいことを
示すものである。 In this way, the present application makes measurement possible by selecting the same material as the test object for the other electrode and setting it in an activated state.The high initial potential means that the material is dense and relatively thick. This indicates that a chemical film has been formed, and the persistence of the potential indicates that the formed film has high strength and corrosion resistance.
一般にステンレス鋼の不働態領域は甘汞電極対
象自然電極電位で＋200ｍＶ乃至＋1000ｍＶ程度
と考えられているが、本発明の実施例に於ける測
定値はこれとよく一致することが確認された。 In general, the passive region of stainless steel is considered to be about +200 mV to +1000 mV in terms of the natural electrode potential of the Gampa electrode, and it was confirmed that the measured values in the examples of the present invention were in good agreement with this.
ところで上記実施例に於いては電気液になる１
規定の硫酸溶液を用いたが、必ずしもこれに限定
する必要はなく、これより濃い場合は不働態被膜
の溶解時間が早いため初期電位の持続時間が短か
く、又逆にこれより薄い場合には持続時間が長く
なるため適当に所定濃度に規定したうえで標準被
検体と比較すればよく、また電解液の種類につい
ても被検体金属の種類に応じて硫酸以外に塩酸な
どの如き腐食性で還元性の酸であれば使用するこ
とが出来る。 By the way, in the above embodiment, the electrolytic liquid 1
Although a specified sulfuric acid solution was used, it is not necessarily limited to this; if the concentration is higher than this, the initial potential will be shortened due to the rapid dissolution time of the passive film; Since the duration is long, it is only necessary to set the concentration to an appropriate predetermined value and then compare it with the standard specimen.Also, depending on the type of electrolyte, it is possible to use a corrosive reducing agent such as hydrochloric acid in addition to sulfuric acid, depending on the type of metal being tested. Any suitable acid can be used.
一方、電極の材質については被検体と異種の材
質の場合には不働態化とは無関係に各組合せ材種
毎に所謂る一次電池を形成することゝなるため各
組合せ毎に電位の発生がみられる。 On the other hand, if the material of the electrode is different from that of the specimen, a so-called primary battery will be formed for each material combination regardless of passivation, so a potential will be generated for each combination. It will be done.
しかし本願に於ては、常に被検体と同一材種の
電極を用いるため、この種の異種材間に発生する
一次電池形成による電位は示さず、また測定に際
しては常に活性化した状態で測定することを必須
条件とするため前述の如く被検体が不働態化され
ておれば材種に応じて500乃至600ｍＶ程度の自然
発生電位が得られるが、万一被検体表面も活性化
された状態にあるときは電位の発生は全く見られ
ない。 However, in this application, since we always use an electrode made of the same material as the test object, we do not show the potential caused by the formation of a primary battery that occurs between different materials, and measurements are always made in an activated state. Since this is an essential condition, if the specimen is passivated as mentioned above, a spontaneous potential of about 500 to 600 mV can be obtained depending on the material, but in the unlikely event that the specimen surface is also activated. At some times, no potential is generated at all.
つまり被検体が活性化状態にあるときは自然発
生電位はみられず、逆に不働態化しているときは
その程度に応じて電位が大きく、またその不働態
化膜の厚みに応じて経時的に電位が減衰しついに
は零に近づくため容易にその程度を測定すること
が出来る点に特徴がある。 In other words, when the subject is in an activated state, no spontaneously generated potential is observed; on the other hand, when the subject is in a passivated state, the potential is large depending on the degree, and the potential changes over time depending on the thickness of the passivated film. It is characterized by the fact that the potential attenuates and eventually approaches zero, making it easy to measure the extent of this.
また測定に際して行なう電極の活性化の手段と
しては、前述の実施例に於ける如くエメリーペー
パーなども用いて研磨する方法のほか、稀硫酸や
塩酸などの如き還元性の酸液中に短時間浸漬する
ことによつても同様の効果が得られるものであ
る。 In addition, as a means of activating the electrode during measurement, in addition to polishing with emery paper as in the above-mentioned example, short-term immersion in a reducing acid solution such as dilute sulfuric acid or hydrochloric acid can be used. Similar effects can also be obtained by doing so.
而して本発明測定法を実施するに当つては、専
門的な知識や熟練は何ら必要とせずして容易に実
施し得るのみならず、既に取り付けを終了した部
材の測定、或は多数の被検体の測定等種々の現場
的要求に即応し、製品、素材等を何ら損傷するこ
とがなく、極めて迅速簡易に実施することが出来
るなど公知の方法に比べて多くの利点があげられ
る。 Therefore, in carrying out the measurement method of the present invention, it is not only easy to carry out without requiring any specialized knowledge or skill, but also to measure parts that have already been installed, or to measure a large number of parts. This method has many advantages over known methods, such as being able to quickly respond to various on-site requirements such as measurement of objects, causing no damage to products, materials, etc., and being extremely quick and easy to implement.
要するに、本発明によればステンレス鋼の金属
被検体を直接一極とし、該被検体と同一材質より
なり活性化状態とした他の一極を規定濃度の硫酸
などの電解液を含浸せしめた紙などの滞水性紙
葉状物質を介して該被検体表面に接触せしめると
共に、両極間に電位差計を配して自然発生電位を
測定して標準被検体と比較するか、或は予め標準
被検体について求めておいた不働態化の程度と自
然発生初期電位並びに該電位の経時的減衰状態と
の関係を比較することにより、金属被検体表面の
不働態化効果を現場的にしかも極めて簡易なる装
置及び操作をもつて迅速、確実且つ如何なる形状
の被検体についても現場的に容易に測定し得るも
ので産業上極めて有益である。 In short, according to the present invention, one electrode is directly made of a stainless steel metal object, and the other electrode made of the same material as the object and in an activated state is a paper impregnated with an electrolytic solution such as sulfuric acid at a specified concentration. Contact the surface of the specimen through a water-retentive paper sheet such as, and measure the naturally occurring potential by placing a potentiometer between the two electrodes and compare it with a standard specimen, or By comparing the relationship between the determined degree of passivation, the naturally occurring initial potential, and the state of decay of this potential over time, it is possible to evaluate the passivation effect on the surface of a metal object on-site and with an extremely simple device. It is extremely useful industrially because it can be operated quickly, reliably, and easily on-site to measure objects of any shape.
図面は本発明方法の原理を示す概略図である。
１……被検体、２……電極、３……紙、５…
…電位差計。
The drawing is a schematic diagram illustrating the principle of the method of the invention. 1... Subject, 2... Electrode, 3... Paper, 5...
...Potentiometer.
Claims (1)
とし、該被検体と同一材質よりなり活性化状態と
した他の−極は被検体を溶解することができる電
解液を含浸せしめた帯水性紙葉物質を介して上記
被検体表面に接触せしめると共に、該両極間の自
然発生電位を測定し、該発生電位の変化から被検
体の不働態化の程度を判定する如くしたことを特
徴とする金属の不働態化効果の簡易測定方法。1. The stainless steel specimen to be measured is used as the direct electrode, and the other electrode, which is made of the same material as the specimen and is in an activated state, is a water-retaining paper impregnated with an electrolyte capable of dissolving the specimen. A metal that is brought into contact with the surface of the subject through leaf matter, measures a spontaneously generated potential between the two electrodes, and determines the degree of passivation of the subject from changes in the generated potential. A simple method for measuring the passivation effect of
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60093352A JPS61251762A (en) | 1985-04-30 | 1985-04-30 | Simple measuring method for passivation effect of metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60093352A JPS61251762A (en) | 1985-04-30 | 1985-04-30 | Simple measuring method for passivation effect of metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61251762A JPS61251762A (en) | 1986-11-08 |
| JPH0523386B2 true JPH0523386B2 (en) | 1993-04-02 |
Family
ID=14079879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60093352A Granted JPS61251762A (en) | 1985-04-30 | 1985-04-30 | Simple measuring method for passivation effect of metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61251762A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021015039A (en) * | 2019-07-12 | 2021-02-12 | 株式会社日立プラントサービス | Processing device, processing system, and production system |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO20160373A1 (en) | 2016-03-03 | 2017-09-04 | Vetco Gray Scandinavia As | Rapid non-destructive evaluation of the degree of sensitization in stainless steels and nickel based alloys |
| JP7089751B2 (en) * | 2018-07-24 | 2022-06-23 | 株式会社ケミカル山本 | Simple measurement method and evaluation electrolyte for metal surface condition |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5012317A (en) * | 1973-06-08 | 1975-02-07 | ||
| JPS5181688A (en) * | 1975-01-14 | 1976-07-17 | Mitsubishi Heavy Ind Ltd | KINZOKUZAIRYONOBUNSEKIHOHO |
| JPS5332090A (en) * | 1976-09-06 | 1978-03-25 | Hitachi Ltd | Grain boundary corrosion detecting method |
-
1985
- 1985-04-30 JP JP60093352A patent/JPS61251762A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5012317A (en) * | 1973-06-08 | 1975-02-07 | ||
| JPS5181688A (en) * | 1975-01-14 | 1976-07-17 | Mitsubishi Heavy Ind Ltd | KINZOKUZAIRYONOBUNSEKIHOHO |
| JPS5332090A (en) * | 1976-09-06 | 1978-03-25 | Hitachi Ltd | Grain boundary corrosion detecting method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2021015039A (en) * | 2019-07-12 | 2021-02-12 | 株式会社日立プラントサービス | Processing device, processing system, and production system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61251762A (en) | 1986-11-08 |
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|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |