JPH0347706B2 - - Google Patents
Info
- Publication number
- JPH0347706B2 JPH0347706B2 JP14710284A JP14710284A JPH0347706B2 JP H0347706 B2 JPH0347706 B2 JP H0347706B2 JP 14710284 A JP14710284 A JP 14710284A JP 14710284 A JP14710284 A JP 14710284A JP H0347706 B2 JPH0347706 B2 JP H0347706B2
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen
- pressure vessel
- diffusion coefficient
- amount
- pressure
- 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
Links
- 229910052739 hydrogen Inorganic materials 0.000 claims description 122
- 239000001257 hydrogen Substances 0.000 claims description 122
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 97
- 238000000034 method Methods 0.000 claims description 39
- 238000009792 diffusion process Methods 0.000 claims description 34
- 150000002431 hydrogen Chemical class 0.000 claims description 33
- 239000000463 material Substances 0.000 claims description 17
- 230000006866 deterioration Effects 0.000 claims description 8
- 230000003628 erosive effect Effects 0.000 claims description 6
- 239000007789 gas Substances 0.000 description 14
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 10
- 238000000605 extraction Methods 0.000 description 9
- 238000005260 corrosion Methods 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 7
- 239000010959 steel 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
- 238000001514 detection method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- MNWBNISUBARLIT-UHFFFAOYSA-N sodium cyanide Chemical compound [Na+].N#[C-] MNWBNISUBARLIT-UHFFFAOYSA-N 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Environmental & Geological Engineering (AREA)
- Environmental Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Description
【発明の詳細な説明】
本発明は、高温高圧水素下で操業される圧力容
器の保守、更に詳しくは圧力容器における水素侵
食の事前検出方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to maintenance of pressure vessels operated under high temperature and high pressure hydrogen, and more particularly to a method for detecting hydrogen erosion in pressure vessels in advance.
石油精製工場における重油脱硫装置、石炭液
化、ガス化工業においては高温高圧水素下での操
業は不可避である。しかし、上記環境に長時間曝
された鉄鋼材料では水素侵食と呼ばれる材質の劣
化現象が生じ、安全操業上重要な問題となつてい
る。これは、ミクロには鋼中の炭化物と鋼中に侵
食してきた水素が反応して、粒界にメタンガスバ
ルブを生ずる現象であり、マクロには材料に特有
の潜状期の後に急激に機械的性質が劣化すること
が特徴である。 Operation under high temperature and high pressure hydrogen is unavoidable in heavy oil desulfurization equipment in oil refineries, coal liquefaction, and gasification industries. However, in steel materials exposed to the above environment for a long time, a phenomenon of deterioration of the material called hydrogen corrosion occurs, which is an important problem for safe operation. Microscopically, this is a phenomenon in which carbides in the steel react with hydrogen that has eroded into the steel, producing methane gas valves at the grain boundaries, and macroscopically, it is a phenomenon in which methane gas valves occur at grain boundaries, and mechanical gas valves suddenly appear after a latent period peculiar to the material. It is characterized by deterioration of properties.
圧力容器用材料の水素侵食の発生を事前に検知
することは、安全操業の面からもきわめて重要で
ある。しかし、今まで水素侵食の事前検知方法は
なく、機械的性質の劣化が生じた場合に、はじめ
て水素侵食が発生していたことを知るのが現状で
あつた。 Detecting the occurrence of hydrogen corrosion in pressure vessel materials in advance is extremely important from the standpoint of safe operation. However, until now there has been no method for detecting hydrogen attack in advance, and the current situation is that it is only known that hydrogen attack has occurred when mechanical properties deteriorate.
一方、経験的に水素侵食による事故例をもと
に、材料毎に水素侵食が起きるまでの時間（安全
操業が可能な期間）と水素圧、温度を関係づけた
ネルソン線図が作成されており、圧力容器の設
計、保守の面での目安となつている。しかし、ネ
ルソン線図が示している安全領域でも事故の発生
が報告される等、ネルソン線図は信頼性に乏し
く、同一鋼種であつても水素侵食の起きるまでの
時間は大きく異なることがわかつてきた。圧力容
器の正確な寿命予測を行うには、あくまでも、そ
の圧力容器材料そのもの（同一チヤージで、しか
も同様の熱処理を施したもの）で試験を行う必要
がある。 On the other hand, based on empirical examples of accidents caused by hydrogen corrosion, Nelson diagrams have been created that relate the time until hydrogen corrosion occurs (the period during which safe operation is possible), hydrogen pressure, and temperature for each material. , which serves as a guideline for pressure vessel design and maintenance. However, the Nelson diagram is unreliable, as accidents have been reported even in the safe area indicated by the Nelson diagram, and it has been found that the time it takes for hydrogen corrosion to occur varies greatly even for the same steel type. came. In order to accurately predict the lifespan of a pressure vessel, it is necessary to conduct tests on the pressure vessel material itself (with the same charge and heat treatment).
本発明は以上の状況にかんがみてなされたもの
で、水素侵食による機械的性質の劣化の前後の
種々の材質特性を調査した結果、機械的性質の劣
化に先だつて材料の水素拡散係数が著しく低下す
ることを見出し、なされたもので、高温高圧水素
下で操業される圧力容器における水素侵食を事前
に検出する方法を提供することを目的とする。 The present invention was developed in view of the above circumstances, and as a result of investigating various material properties before and after deterioration of mechanical properties due to hydrogen erosion, it was found that the hydrogen diffusion coefficient of the material significantly decreases prior to deterioration of mechanical properties. The purpose of this invention is to provide a method for detecting hydrogen corrosion in a pressure vessel operated under high temperature and high pressure hydrogen.
すなわち、本発明は、高温高圧水素下で操業さ
れる圧力容器において生ずる水素侵食に起因する
材質劣化時期の接近を、水素拡散係数の急変によ
り予知することを特徴とする圧力容器における水
素侵食の事前検出方法を提供するものである。 That is, the present invention provides a method for predicting the impending timing of material deterioration due to hydrogen erosion in a pressure vessel operated under high temperature and high pressure hydrogen, using a sudden change in the hydrogen diffusion coefficient. A detection method is provided.
以下、本発明を更に詳細に説明する。 The present invention will be explained in more detail below.
本発明の骨子は、材料の水素拡散係数の変化か
ら圧力容器の寿命（機械的性質の劣化の始まり）
を予想する点にある。 The gist of the present invention is to determine the lifespan of a pressure vessel (the beginning of deterioration of mechanical properties) from changes in the hydrogen diffusion coefficient of the material.
The point is to predict.
第１図および第２図は本発明の基礎となる実験
結果であり、それぞれ圧力容器用２本Cr−1Mo
鋼を、圧力300atm、温度600℃の高温高圧水素ガ
ス雰囲気で長時間暴露試験を行つた場合の室温で
の水素拡散係数、およびシヤルピー衝撃試験によ
る０℃での吸収エネルギーの変化を示す。比較の
ために1atm、600℃のアルゴン中で熱処理した材
料における結果も同一図中に示す。 Figures 1 and 2 show the experimental results that form the basis of the present invention.
This figure shows the hydrogen diffusion coefficient at room temperature when steel is subjected to a long-term exposure test in a high-temperature, high-pressure hydrogen gas atmosphere at a pressure of 300 atm and a temperature of 600°C, and changes in absorbed energy at 0°C in a Charpy impact test. For comparison, the results for materials heat-treated in argon at 1 atm and 600°C are also shown in the same figure.
これらの図により、高温高圧水素処理を行つた
材料においては、水素侵食による吸収エネルギー
の低下に先だつて水素拡散係数が著しく低下して
いること、この現象を利用すれば水素侵食による
材質劣化の事前検知が可能であることがわかる。 These figures show that in materials subjected to high-temperature, high-pressure hydrogen treatment, the hydrogen diffusion coefficient significantly decreases before the absorption energy decreases due to hydrogen attack, and this phenomenon can be used to prevent material deterioration due to hydrogen attack. It can be seen that detection is possible.
このような高温高圧水素処理材での水素拡散係
数の低下の原因は、鋼中の炭化物と水素の反応に
より生じた微細なメタンガスボイドが水素のトラ
ツプサイトとなり、水素の拡散を阻害することに
よると考えられる。メタンガスボイドが更に成長
合体して大きな亀裂となつたときに、はじめて機
械的性質の劣化が生じるものと思われる。 The reason for this decrease in the hydrogen diffusion coefficient in high-temperature, high-pressure hydrogen-treated materials is thought to be that the fine methane gas voids generated by the reaction between carbides in the steel and hydrogen become trap sites for hydrogen and inhibit hydrogen diffusion. It will be done. It is thought that the mechanical properties deteriorate only when the methane gas voids further grow and coalesce into large cracks.
さて、この現象を利用して実際の圧力容器の寿
命を予知するには次の２種類の方法が可能であ
る。 Now, the following two methods are possible to predict the actual lifespan of a pressure vessel using this phenomenon.
(1) 間接法：圧力容器と同一チヤージで溶製し、
同様の熱処理を施した小型試験片を、圧力容器
内のトレー上で実機暴露を行い、シヤツトダウ
ン時に１枚ずつ取り出し、水素拡散係数を測定
する方法。(1) Indirect method: Molten at the same charge as the pressure vessel,
A method in which small test pieces that have been subjected to similar heat treatment are exposed to actual equipment on a tray inside a pressure vessel, and then taken out one by one at shutdown to measure the hydrogen diffusion coefficient.
(2) 直接法：圧力容器に直接水素透過量測定装置
をとりつけ、圧力容器壁を透過してきた水素量
から水素拡散係数を算出する方法。(2) Direct method: A method in which a hydrogen permeation measurement device is attached directly to the pressure vessel and the hydrogen diffusion coefficient is calculated from the amount of hydrogen that has permeated through the pressure vessel wall.
(A) 間接法による場合の水素拡散係数Ｄの算出方
法
(1‐1) 透過法
第３図に示すように0.5〜３mm厚の板状サ
ンプルの片面に水素ガス又は水素ガスと不活
性ガスの混合ガスを流す。水素の一部は試料
中へ侵入透過し、ある時間後、水素引抜側に
湧出してくる。単位時間あたりの水素湧出量
の時間変化をガス分析装置、Ｕ字管による圧
力変化等から測定する。なお、第３図におい
て、１はサンプル、９は水素チヤージ側、１
０は水素引抜側である。(A) Calculation method of hydrogen diffusion coefficient D using indirect method (1-1) Permeation method As shown in Figure 3, hydrogen gas or a mixture of hydrogen gas and inert gas is applied to one side of a plate-shaped sample with a thickness of 0.5 to 3 mm. Flow the mixed gas. A part of the hydrogen penetrates into the sample and after a certain period of time comes out on the hydrogen extraction side. The time change in the amount of hydrogen gushing out per unit time is measured using a gas analyzer, pressure change using a U-shaped tube, etc. In addition, in Fig. 3, 1 is the sample, 9 is the hydrogen charge side, 1
0 is the hydrogen extraction side.
さて、水素ガスチヤージ開始後の引抜側で
の単位時間あたりの水素湧出量Jt（mol／cm2
sec）は、拡散方程式をもとにした計算によ
り下記のように表わされる。 Now, the amount of hydrogen gushing out per unit time J t (mol/cm 2
sec) is expressed as follows by calculation based on the diffusion equation.
Jt／J∞＝２／√πτｅ×ｐ（−１／4τ）小
１−2e×ｐ（−π2τ）τ大
τ＝Dt／L2 (1)
J∞（mol／cm2sec）：定常状態での水素湧出量
Ｄ（cm2／sec）：拡散係数
Ｌ（cm）：サンプル厚み
ｔ（sec）：水素チヤージ開始後の時間
(1)式により水素湧出量Jtは時間の対数を横
軸にとると第４図に示すような変化をする。 J t /J ∞ = 2/√πτe×p (-1/4τ) small 1-2e×p (-π 2 τ) τ large τ=Dt/L 2 (1) J ∞ (mol/cm 2 sec) : Amount of hydrogen seeping out in steady state D (cm 2 /sec): Diffusion coefficient L (cm): Sample thickness t (sec): Time after starting hydrogen charge According to equation (1), hydrogen seeping amount J t is the logarithm of time. When plotted on the horizontal axis, there is a change as shown in Figure 4.
次に水素湧出量の時間変化の実測値を時間
の対数を横軸にとりプロツトする。サンプル
の汚れ、水素の漏れ等の不具合がなければ、
実測値のプロツトは第４図と同じ形となる。
実測曲線と現論曲線を重ね合せ、一致した時
のτ（＝Dt／L2）と時間ｔの関係を求めれば、
拡散係数Ｄを算出できる。たとえばＪ／J∞＝
0.5となる時間t0.5を実測曲線からよみとる。
理論曲線によれば、Ｊ／J∞＝0.5となるτの
値τ0.5は0.1405であるからτ0.5＝Dt0.5／L22＝0.1405
の関係からＤが求まる。 Next, the measured value of the temporal change in the amount of hydrogen gushing is plotted with the logarithm of time on the horizontal axis. If there are no problems such as sample contamination or hydrogen leakage,
The plot of the measured values has the same shape as in Figure 4.
The diffusion coefficient D can be calculated by superimposing the measured curve and the theoretical curve and finding the relationship between τ (=Dt/L 2 ) and time t when they match. For example, J/J ∞ =
Read the time t 0.5 at which the value becomes 0.5 from the measured curve.
According to the theoretical curve, the value τ 0.5 for J/J ∞ = 0.5 is 0.1405, so D can be found from the relationship τ 0.5 = Dt 0.5 /L 22 = 0.1405.
(1‐2) 陰極チヤージ透過法
0.5〜３mm厚の板状試料の片面に、水素の
イオン化効率を上げるためにパラジウムまた
はニツケルを薄くメツキし、第５図に示すよ
うに試料をセツトし、ガルバノスタツト及び
ポテンシヨスタツトと接続する。なお、第５
図において、１はサンプル、２は電極、３は
標準電極、４はガルバノスタツト、５はポテ
ンシヨスタツト、６はレコーダー、７は水素
チヤージ液、８は水素引抜液である。試料の
チヤージ側にNaOH＋NaCN溶液あるいは
H2SO4＋AS2O3等の電解チヤージ液をみた
し、水素引抜側にNaOH溶液をみたす。次
にガルバノスタツトに一定電流を流すと、試
料表面で電解反応により水素が発生し、一部
は試料中を拡散透過し、水素引抜面（メツキ
面）に湧出してくる。水素引抜側で、あらか
じめ試料と標準電極の間にポテンシヨスタツ
トのより一定電位（鉄鋼材料の腐食電流の流
れない−100〜＋200mv程度の電位）をかけ
ておけば、水素引抜面へ湧出してきた水素は
イオン化して溶液中を流れ、電極にまで到達
する。したがつて、試料と電極間の電流変化
をレコーダーで記録すれば、水素透過量の時
間変化を知ることができる。水素チヤージ開
始後の水素透過量は第４図で示したような時
間変化を示し、水素湧出量を電流でよみかえ
ればよい。後の解析は(1)の透過法の場合と同
様である。 (1-2) Cathode charge transmission method One side of a plate-shaped sample with a thickness of 0.5 to 3 mm is plated with a thin layer of palladium or nickel to increase hydrogen ionization efficiency, and the sample is set as shown in Figure 5, and galvanized. Connect to a stat and a potentiometer. In addition, the fifth
In the figure, 1 is a sample, 2 is an electrode, 3 is a standard electrode, 4 is a galvanostat, 5 is a potentiostat, 6 is a recorder, 7 is a hydrogen charging liquid, and 8 is a hydrogen extraction liquid. Apply NaOH+NaCN solution or
Fill with electrolytic charge liquid such as H 2 SO 4 + AS 2 O 3 , and fill with NaOH solution on the hydrogen extraction side. Next, when a constant current is applied to the galvanostat, hydrogen is generated by an electrolytic reaction on the sample surface, and some of it diffuses through the sample and gushes out on the hydrogen extraction surface (plated surface). On the hydrogen extraction side, if you apply a more constant potential with a potentiostat between the sample and the standard electrode (about -100 to +200mv potential where corrosion current does not flow in steel materials), hydrogen will gush out to the extraction surface. Hydrogen is ionized and flows through the solution, reaching the electrodes. Therefore, by recording the current change between the sample and the electrode with a recorder, it is possible to know the time change in the amount of hydrogen permeation. The amount of hydrogen permeation after the start of hydrogen charging shows a time change as shown in FIG. 4, and the amount of hydrogen gushing can be read back using the current. The subsequent analysis is the same as that for the transmission method in (1).
(B) 直接法による場合の水素拡散係数Ｄの算出方
法。(B) Calculation method of hydrogen diffusion coefficient D using direct method.
圧力容器はほぼ一定の温度、水素分圧となつ
ており、圧力容器表面には水素分圧に応じた量
の水素C0が固溶しており、外表面は大気に接
しているため固溶量は０である。その間は外表
面からの距離に比例した水素固溶量となつてお
り、水素捕集治具内へ湧出してくる単位時間あ
たりの水素量Ｊは一定である。圧力容器内表面
の水素固溶量C0を知れば、水素湧出量の測定
値から拡散方程式を使い、次式により拡散係数
Ｄを求めることができる。 The pressure vessel has an almost constant temperature and hydrogen partial pressure, and an amount of hydrogen C 0 corresponding to the hydrogen partial pressure is dissolved in solid solution on the surface of the pressure vessel. The amount is 0. During this period, the amount of hydrogen solid solution is proportional to the distance from the outer surface, and the amount J of hydrogen gushing out into the hydrogen trapping jig per unit time is constant. If the solid solution amount C 0 of hydrogen on the inner surface of the pressure vessel is known, the diffusion coefficient D can be determined from the following equation using the diffusion equation from the measured value of the hydrogen gushing amount.
Ｄ＝JL／C0
Ｄ （５／sec）：拡散係数
Ｊ （mol／cm2sec：水素湧出量
C0 （mol／cm3）：内表面での水素固溶量
Ｌ （cm）：容器壁厚み
内表面の水素固溶量が知られない場合は、シ
ヤツトダウンン時（操業停止時）に水素を放出
した場合の外表面への水素湧出量の時間変化を
測定すればよい。この場合の水素放出後の単位
時間あたりの水素湧出量Jt（mol／cm2sec）は次
のように表すことができ、第６図に示すような
変化を示す。 D=JL/C 0 D (5/sec): Diffusion coefficient J (mol/cm 2 sec: Amount of hydrogen seeping out C 0 (mol/cm 3 ): Amount of hydrogen solid solution on the inner surface L (cm): Container wall Thickness If the amount of hydrogen solid solution on the inner surface is not known, it is sufficient to measure the time change in the amount of hydrogen gushing out to the outer surface when hydrogen is released during shutdown (operation stoppage).Hydrogen release in this case The subsequent hydrogen gushing amount J t (mol/cm 2 sec) per unit time can be expressed as follows, and shows changes as shown in FIG.
Jt／J∞＝１−２／√πτｅ×ｐ（−１／4τ）（τ小
）
2e×ｐ（−π2τ）
τ＝Dt／L2 (2)
J∞（mol／cm2sec）：定常状態（水素放出前）の
水素湧出量
Ｄ（cm2／sec）：拡散係数
ｔ（sec）：水素放出後の時間
Ｌ（cm）：容器壁厚み
水素放出後の水素湧出量を縦軸に、時間の対数
を横軸にプロツトし、理論曲線と比較することに
より拡散係数Ｄを求めることができる。 J t /J ∞ =1-2/√πτe×p(-1/4τ) (τ small) 2e×p(-π 2 τ) τ=Dt/L 2 (2) J ∞ (mol/cm 2 sec ): Amount of hydrogen gushing out in steady state (before hydrogen release) D (cm 2 /sec): Diffusion coefficient t (sec): Time after hydrogen release L (cm): Container wall thickness By plotting the logarithm of time on the axis and the logarithm of time on the horizontal axis and comparing it with a theoretical curve, the diffusion coefficient D can be determined.
以上、水素拡散係数算出のための手順の一例を
示した。水素拡散係数の測定法は、この他にも放
出法、吸収法等があり、それぞれの場合の最も適
切な方法を選択し測定すべきである。 An example of the procedure for calculating the hydrogen diffusion coefficient has been described above. There are other methods for measuring the hydrogen diffusion coefficient, such as a desorption method and an absorption method, and the most appropriate method for each case should be selected and measured.
上述した(1)の間接法は小型試験片を使用するこ
とから実験室内で測定でき、簡便である。また測
定法も透過法、陰極チヤージ透過法、放出法、吸
収法等のいずれかの方法でもよく、測定者の都合
のよい方法を選択すればよい。本発明では測定方
法は限定しない。 The above-mentioned indirect method (1) uses a small test piece, so it can be measured in a laboratory and is simple. Further, the measurement method may be any of the transmission method, cathode charge transmission method, emission method, absorption method, etc., and the measurer may select a method convenient for him. In the present invention, the measurement method is not limited.
上述した(2)の直接法による測定法を第７図に示
す。バルブ付ステンレス鋼製パイプ２本のついた
オーステナイトステンレス鋼製の水素捕集用治具
１１を圧力容器１２の外側にとりつける。とりつ
け法はとくに限定しないが、捕集した水素ガスを
大気中へ漏らさないことが肝要であり、溶接によ
るとりつけが望ましい。 FIG. 7 shows the measurement method using the direct method described in (2) above. A hydrogen trapping jig 11 made of austenitic stainless steel and having two stainless steel pipes with valves is attached to the outside of the pressure vessel 12. Although the attachment method is not particularly limited, it is important that the collected hydrogen gas does not leak into the atmosphere, and attachment by welding is preferable.
圧力容器１２の壁を圧力容器内部１３より透過
してきた水素は、水素捕集治具１１内に湧出して
くる。水素の単位時間あたりの湧出量は水素拡散
係数に比例するから、湧出量の測定から水素拡散
係数を算出できる。湧出してきた水素は、バルブ
１４を有するステンレスパイプ１５あるいはバル
ブ１６を有するステンレスバルブ１７を経て、ガ
ス分析装置へ導入される。 Hydrogen that has permeated the wall of the pressure vessel 12 from the inside 13 of the pressure vessel gushes out into the hydrogen collection jig 11. Since the amount of hydrogen gushing out per unit time is proportional to the hydrogen diffusion coefficient, the hydrogen diffusion coefficient can be calculated from the measurement of the gushing amount. The hydrogen that has come out is introduced into the gas analyzer through a stainless steel pipe 15 having a valve 14 or a stainless steel valve 17 having a valve 16.
水素ガス湧出法の測定には、ガス質量分析装置
を始めとする検出感度の高い装置を使う場合と、
圧力変化から湧出量を求めるＵ字管等検出感度の
それほど高くない機器を用いる場合がある。 For hydrogen gas gushing measurements, there are two methods: using a device with high detection sensitivity, such as a gas mass spectrometer, and
In some cases, equipment such as a U-shaped tube that determines the amount of gush from pressure changes is used that does not have high detection sensitivity.
ガス質量分析装置を使用した場合、Heをキヤ
リアーガスとして水素を分析装置内に導くとよ
い。すなわちパイプ１５を通してHeガスを水素
捕集治具１１内に導入し、圧力容器１２の壁を透
過湧出してきた水素ガスと混合させる。混合ガス
はパイプ１７を通して分析機器内に導かれ、分析
される。 When using a gas mass spectrometer, hydrogen may be introduced into the analyzer using He as a carrier gas. That is, He gas is introduced into the hydrogen collection jig 11 through the pipe 15 and mixed with the hydrogen gas that has permeated through the wall of the pressure vessel 12 and seeped out. The mixed gas is led into the analytical instrument through pipe 17 and analyzed.
ガス分析装置の検出感度があまり高くない場合
は、水素ガスを一定時間ため込んで測定するとよ
い。まずパイプ１５を真空ポンプにつなぎ、バル
ブ１４を開けて水素捕集治具１１内を真空に引
く。次いでバルブ１４，１６を閉じ、一定時間水
素を捕集する。十分な量の水素が捕集された後バ
ルブ１６を開け、水素ガスを分析装置内に導いて
水素湧出量を測定する。 If the detection sensitivity of the gas analyzer is not very high, it is recommended to store hydrogen gas for a certain period of time and then measure it. First, the pipe 15 is connected to a vacuum pump, the valve 14 is opened, and the inside of the hydrogen collection jig 11 is evacuated. Then, the valves 14 and 16 are closed to collect hydrogen for a certain period of time. After a sufficient amount of hydrogen has been collected, the valve 16 is opened and the hydrogen gas is introduced into the analyzer to measure the amount of hydrogen gushing out.
どちらのガス捕集方法を採用するかは、分析装
置の感度と水素湧出量（圧力容器内の温度、水素
圧、圧力容器の厚さ等に依存）を比較して決定す
べきである。 Which gas collection method to adopt should be determined by comparing the sensitivity of the analyzer and the amount of hydrogen gushing out (depending on the temperature in the pressure vessel, hydrogen pressure, thickness of the pressure vessel, etc.).
水素捕集治具の取り付けにあたつては、圧力容
器外壁のとりつけ位置の塗料、サビ、油脂等を除
去し、清浄な状態にしておくことが測定精度を上
げるために重要である。 When installing the hydrogen trapping jig, it is important to remove paint, rust, oil, etc. from the mounting position on the outer wall of the pressure vessel and keep it in a clean state in order to improve measurement accuracy.
水素捕集治具をオーステナイトステンレス鋼製
としたのは、オーステナイト鋼は水素拡散係数が
十分小さく、治具を透過して水素が逃散すること
がほとんどないからである。 The reason why the hydrogen trapping jig was made of austenitic stainless steel is that austenitic steel has a sufficiently small hydrogen diffusion coefficient, and hydrogen hardly escapes by passing through the jig.
次に、本発明を実施例につき具体的に説明す
る。 Next, the present invention will be specifically explained using examples.
温度450℃、水素分圧150atmで操業している圧
力容器における水素拡散係数の変化を第８図、第
９図に示す。第８図は圧力容器材と同一チヤージ
で得られた小型試験片を圧力容器内に装入して暴
露し、取り出して陰極チヤージ透過法で測定した
室温での水素拡散係数である（間接法）。第９図
は圧力容器外壁に捕集装置を取りつけ、室温まで
シヤツトダウンした場合の水素拡散係数を測定し
た結果である。これらの図から、７万時間の操業
で水素拡散係数の低下が認められた。７万時間暴
露後の小型試験片の組織を観察したところ、第１
０図の400倍顕微鏡写真に示すように、極く一部
の粒界に水素侵食によるメタンバブルと思われる
ボイドが認められた。 Figures 8 and 9 show changes in the hydrogen diffusion coefficient in a pressure vessel operated at a temperature of 450°C and a hydrogen partial pressure of 150 atm. Figure 8 shows the hydrogen diffusion coefficient at room temperature measured by the cathodic charge permeation method after placing a small test piece obtained at the same charge as the pressure vessel material into the pressure vessel, exposing it, and taking it out (indirect method). . FIG. 9 shows the results of measuring the hydrogen diffusion coefficient when a collection device was attached to the outer wall of the pressure vessel and the pressure vessel was shut down to room temperature. From these figures, it was observed that the hydrogen diffusion coefficient decreased after 70,000 hours of operation. When we observed the structure of the small test piece after 70,000 hours of exposure, we found that
As shown in the 400x micrograph in Figure 0, voids that were thought to be methane bubbles due to hydrogen erosion were observed at some grain boundaries.
このように実機においても本発明は水素侵食の
早期検出に有効である。 As described above, the present invention is effective for early detection of hydrogen corrosion even in actual equipment.
第１図および第２図は高温高圧水素処理による
水素拡散係数とおよび吸収エネルギーの変化を示
すグラフ。第３図は間接法による水素拡散係数の
測定装置の模式図、第４図および第６図はそれぞ
れ間接法および直接法における水素湧出量と時間
の関係を示すグラフ、第５図は陰極チヤージ透過
法による水素拡散係数の測定装置の模式図、第７
図は直接法による水素拡散係数の測定装置の模式
図、第８図および第９図はそれぞれ実機における
間接法、直接法による水素拡散係数の変化を示す
グラフ、第１０図は圧力容器の金属組織の顕微鏡
写真で、第１０図は第８図および第９図における
７万時間操業後の試験片の400倍顕微鏡写真であ
る。
符号の説明、１…サンプル、２…電極、３…標
準電極、４…ガルバノスタツト、５…ポテンシヨ
スタツト、６…レコーダー、７…水素チヤージ
液、８…水素引抜液、９…水素チヤージ側、１０
…水素引抜側、１１…水素捕集治具、１２…圧力
容器、１３…圧力容器内部、１４，１６…バル
ブ、１５，１７…ステンレスパイプ。
FIGS. 1 and 2 are graphs showing changes in hydrogen diffusion coefficient and absorbed energy due to high-temperature and high-pressure hydrogen treatment. Figure 3 is a schematic diagram of a device for measuring the hydrogen diffusion coefficient using the indirect method. Figures 4 and 6 are graphs showing the relationship between the amount of hydrogen gushing out and time in the indirect method and the direct method, respectively. Figure 5 is the cathode charge permeation. Schematic diagram of the device for measuring the hydrogen diffusion coefficient by the method, No. 7
The figure is a schematic diagram of a device for measuring the hydrogen diffusion coefficient using the direct method. Figures 8 and 9 are graphs showing changes in the hydrogen diffusion coefficient using the indirect method and the direct method in actual equipment, respectively. Figure 10 is the metal structure of the pressure vessel. Fig. 10 is a 400x photomicrograph of the test piece shown in Figs. 8 and 9 after 70,000 hours of operation. Explanation of symbols, 1...sample, 2...electrode, 3...standard electrode, 4...galvanostat, 5...potentiostat, 6...recorder, 7...hydrogen charge liquid, 8...hydrogen extraction liquid, 9...hydrogen charge side , 10
...Hydrogen extraction side, 11...Hydrogen collection jig, 12...Pressure vessel, 13...Inside of pressure vessel, 14, 16...Valve, 15, 17...Stainless steel pipe.
Claims (1)
て生ずる水素侵食に起因する材質劣化時期の接近
を、水素拡散係数の急変により予知することを特
徴とする圧力容器における水素侵食の事前検出方
法。1. A method for detecting hydrogen erosion in a pressure vessel in advance, which is characterized by predicting the approaching period of material deterioration due to hydrogen erosion occurring in a pressure vessel operated under high temperature and high pressure hydrogen, based on a sudden change in the hydrogen diffusion coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14710284A JPS6125047A (en) | 1984-07-16 | 1984-07-16 | Preliminary detecting method of hydrogen errosion in pressure container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14710284A JPS6125047A (en) | 1984-07-16 | 1984-07-16 | Preliminary detecting method of hydrogen errosion in pressure container |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6125047A JPS6125047A (en) | 1986-02-03 |
| JPH0347706B2 true JPH0347706B2 (en) | 1991-07-22 |
Family
ID=15422547
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14710284A Granted JPS6125047A (en) | 1984-07-16 | 1984-07-16 | Preliminary detecting method of hydrogen errosion in pressure container |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6125047A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10295453B2 (en) | 2015-03-19 | 2019-05-21 | Jfe Steel Corporation | Gas-phase hydrogen permeation test device and method of protecting gas-phase hydrogen permeation test device |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08226888A (en) * | 1995-02-22 | 1996-09-03 | Japan Atom Energy Res Inst | Structure inspection device |
| JP5081138B2 (en) * | 2008-11-27 | 2012-11-21 | 株式会社神戸製鋼所 | Method for evaluating spalling resistance of steel |
| FR2959014B1 (en) * | 2010-04-19 | 2013-01-04 | Total Raffinage Marketing | TRACKING THE CORROSION SPEED OF A METALLIC CONDUIT CONDUCTED BY A CORROSIVE FLUID |
| JP5363516B2 (en) * | 2011-02-03 | 2013-12-11 | 日本電信電話株式会社 | Hydrogen permeation measuring device |
| JP5700673B2 (en) * | 2011-08-26 | 2015-04-15 | Ｊｆｅスチール株式会社 | Method for measuring amount of hydrogen penetrating into metal and method for monitoring amount of hydrogen penetrating into metal part of moving body |
| JP5777098B2 (en) * | 2011-08-26 | 2015-09-09 | Ｊｆｅスチール株式会社 | Method for measuring amount of hydrogen penetrating into metal and method for monitoring amount of hydrogen penetrating into metal part of moving body |
| FR2997763B1 (en) | 2012-11-06 | 2015-01-16 | Commissariat Energie Atomique | DEVICE AND METHOD FOR ESTIMATING A GAS STREAM IN AN ENCLOSURE CONTINUED IN LOW GAS DEPRESSION |
-
1984
- 1984-07-16 JP JP14710284A patent/JPS6125047A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10295453B2 (en) | 2015-03-19 | 2019-05-21 | Jfe Steel Corporation | Gas-phase hydrogen permeation test device and method of protecting gas-phase hydrogen permeation test device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6125047A (en) | 1986-02-03 |
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