JPS62177492A - Pre-oxidation treatment method - Google Patents
Pre-oxidation treatment methodInfo
- Publication number
- JPS62177492A JPS62177492A JP61017956A JP1795686A JPS62177492A JP S62177492 A JPS62177492 A JP S62177492A JP 61017956 A JP61017956 A JP 61017956A JP 1795686 A JP1795686 A JP 1795686A JP S62177492 A JPS62177492 A JP S62177492A
- Authority
- JP
- Japan
- Prior art keywords
- stainless steel
- oxide film
- temperature
- formation
- water
- 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.)
- Pending
Links
- 238000007254 oxidation reaction Methods 0.000 title claims description 9
- 238000000034 method Methods 0.000 title description 12
- 229910001220 stainless steel Inorganic materials 0.000 claims description 27
- 239000010935 stainless steel Substances 0.000 claims description 27
- 230000015572 biosynthetic process Effects 0.000 claims description 16
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 230000007797 corrosion Effects 0.000 claims description 13
- 238000005260 corrosion Methods 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 13
- 238000010494 dissociation reaction Methods 0.000 claims description 4
- 238000001179 sorption measurement Methods 0.000 claims description 4
- 208000018459 dissociative disease Diseases 0.000 claims description 2
- 230000002401 inhibitory effect Effects 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 238000003672 processing method Methods 0.000 claims 1
- 239000010408 film Substances 0.000 description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 19
- 239000000463 material Substances 0.000 description 14
- 150000002500 ions Chemical class 0.000 description 9
- 238000012986 modification Methods 0.000 description 9
- 230000004048 modification Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 7
- 239000010410 layer Substances 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000000498 cooling water Substances 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 5
- 238000002161 passivation Methods 0.000 description 5
- 230000002285 radioactive effect Effects 0.000 description 5
- 239000010409 thin film Substances 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000011651 chromium Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000010287 polarization Effects 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000010348 incorporation Methods 0.000 description 3
- 229910021645 metal ion Inorganic materials 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- YPNVIBVEFVRZPJ-UHFFFAOYSA-L silver sulfate Chemical compound [Ag+].[Ag+].[O-]S([O-])(=O)=O YPNVIBVEFVRZPJ-UHFFFAOYSA-L 0.000 description 3
- 229910000367 silver sulfate Inorganic materials 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000005593 dissociations Effects 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910001347 Stellite Inorganic materials 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 238000007743 anodising Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- AHICWQREWHDHHF-UHFFFAOYSA-N chromium;cobalt;iron;manganese;methane;molybdenum;nickel;silicon;tungsten Chemical compound C.[Si].[Cr].[Mn].[Fe].[Co].[Ni].[Mo].[W] AHICWQREWHDHHF-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- -1 nickel Chemical compound 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005211 surface analysis Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
- Catalysts (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、ステンレス鋼表面からの金属イオンの溶出及
び、放射性イオンの付着を防止するための酸化皮膜形成
方法に係り、特に、沸騰水型原子カプラントの一次冷却
系配管の前酸化処理に好適な酸化皮膜加速形成法に関す
る。Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a method for forming an oxide film to prevent the elution of metal ions from the surface of stainless steel and the adhesion of radioactive ions, and in particular, to The present invention relates to a method for accelerating the formation of an oxide film suitable for pre-oxidation treatment of primary cooling system piping of a couplant.
原子カプラントの一次冷却水系に使用されている配管、
ポンプ、弁等の構造材はステンレス鋼及びステライト鋼
等から構成されている。これらの構造材を構成する金属
は長期間使用されると腐食損傷をうけ、構成金属元素が
一次冷却水中に溶出し、原子炉内に持ち込まれる。溶出
金属元素は大半が酸化物となって燃料棒に付着し、中性
子照射をうける。その結果、”Ｃｏ、’δＣｏ、”Ｃｒ
。Piping used in the primary cooling water system of the nuclear couplant,
Structural materials such as pumps and valves are made of stainless steel, stellite steel, etc. The metals that make up these structural materials are subject to corrosion damage when used for long periods of time, and the constituent metal elements are leached into the primary cooling water and carried into the reactor. Most of the eluted metal elements become oxides and adhere to the fuel rods, where they are exposed to neutron irradiation. As a result, “Co, 'δCo,” Cr
.
”Ｍｎ等の比較的長半減期の放射性核種が生成する。こ
れらの放射性核種は一次冷却水中に再溶出してイオンあ
るいはこのイオンが主として原子炉内で酸化されて生成
する不溶性固体成分（以下、クラッドと称する）として
浮遊する。浮遊する一部は炉水浄化用の脱塩器等で除去
されるが、残りは一次冷却水系を循環しているうちに主
にステンレス鋼からなる構造材表面に付着する。このた
め、構造材表面における線量率が高くなり、保守、点検
を実施する際の作業員の放射線被曝が問題となっている
。線量率低減をはかるため、構造材上の酸化皮膜形成の
初期における放射性イオンの酸化皮膜へのとりこみを抑
制するため、あらかじめ構造材内面への予備酸化が考え
られている。（特開昭５９−１２３９０号・特開昭５９
−３７４９８号）これは、”Ｇｏなどの放射性イオンの
構造材中への取り込み速度が構造材内面への酸化皮膜形
成速度に比例すること、および酸化皮膜の形成速度が高
温水浸漬初期に著しく大きくなることに着目してなされ
ているものである。この場合、予備酸化のためには、構
造材内面を約２５０℃以上の高温水中に浸漬する必要が
あり、しかもステンレス鋼のように腐食速度が小さく、
従って酸化皮膜形成速度が比較的小さい材料に対しては
予備酸化時間を少なくとも数百時間かけなければ放射性
イオンの酸化皮膜へのとり込みを抑制するという効果が
得られないなど、長時間にわたってプラントの運転を中
断することができない実際の原子カプラントに適用する
には問題がある。``Radionuclides with relatively long half-lives such as Mn are generated.These radionuclides are re-eluted into the primary cooling water and become ions or insoluble solid components (hereinafter referred to as Some of the floating part is removed by demineralizers used to purify reactor water, but the rest is deposited on the surface of structural materials, mainly made of stainless steel, while circulating in the primary cooling water system. As a result, the dose rate on the surface of the structural material increases, causing a problem of radiation exposure for workers during maintenance and inspection.In order to reduce the dose rate, oxide films are formed on the structural material. In order to suppress the incorporation of radioactive ions into the oxide film in the early stage of the process, preliminary oxidation of the inner surface of the structural material has been considered.
-37498) This is because "the rate of incorporation of radioactive ions such as Go into the structural material is proportional to the rate of oxide film formation on the inner surface of the structural material, and the rate of oxide film formation is significantly large at the initial stage of immersion in high-temperature water. In this case, for preliminary oxidation, it is necessary to immerse the inner surface of the structural material in high-temperature water of approximately 250°C or higher, and the corrosion rate of the structural material is low, unlike stainless steel. small,
Therefore, for materials with a relatively slow oxide film formation rate, the effect of suppressing the incorporation of radioactive ions into the oxide film cannot be obtained unless the preliminary oxidation time is at least several hundred hours. It is problematic to apply to practical atomic couplets where operation cannot be interrupted.
これに対処して、酸化皮膜を加速形成する方法として、
ステンレス鋼を高温・高圧水中で陽極酸化することが考
えられている。（特開昭５９−６５２９７号）しかし、
高温・高圧水中で複雑な形状の原子カプラント配管を陽
極酸化することは実際上困難で、実用性に欠けるという
問題点がある。To deal with this, as a method to accelerate the formation of an oxide film,
Anodizing stainless steel in high-temperature, high-pressure water is being considered. (Unexamined Japanese Patent Publication No. 59-65297) However,
It is actually difficult to anodize complex-shaped atomic couplant piping in high-temperature, high-pressure water, and there is a problem in that it lacks practicality.
本発明の目的は、原子炉運転条件下における一次冷却系
配管からの金属イオンの溶出抑制及び、冷却水中の放射
性金属イオンの付着抑制に有効な酸化皮膜を加速形成さ
せる処理方法を提供するにある。An object of the present invention is to provide a treatment method for accelerating the formation of an oxide film that is effective in suppressing the elution of metal ions from the primary cooling system piping under reactor operating conditions and in suppressing the adhesion of radioactive metal ions in cooling water. .
［発明の概要〕
高温水中におけるステンレス鋼の腐食挙動を詳細に調べ
た結果、（１）ステンレス鋼の腐食速度が、２６０℃ま
では温度上昇と共に増加するが、２６０℃以上では逆に
温度上昇と共に減少すること、（２）２６０℃を境にし
てステンレス鋼表面に形成される酸化皮膜構造に質的変
化が起り、２６０℃以下ではステンレス鋼表面から溶出
したＦｓ、Ｃｒ、Ｎｉ、イオンが水酸基と反応して（Ｆ
ｅ、Ｃｔ、Ｎ１）（○Ｈ）ｚとなり表面に沈積し、その
後脱水反応により酸化物層に変化するという湿食反応プ
ロセスで酸化皮膜が形成されるのに対し、２６０℃以上
ではステンレス鋼表面に吸着・解離した水中の溶存酸素
が、直接、ステレス鋼内部に拡散することにより、酸化
物層を形成する過程が主になってくることを見い出し、
本発明をなすに至った。[Summary of the invention] As a result of a detailed investigation of the corrosion behavior of stainless steel in high-temperature water, we found that (1) the corrosion rate of stainless steel increases as the temperature rises up to 260°C, but conversely increases as the temperature rises above 260°C; (2) At 260°C, a qualitative change occurs in the oxide film structure formed on the stainless steel surface, and below 260°C, Fs, Cr, Ni, and ions eluted from the stainless steel surface become hydroxyl groups. React (F
e, Ct, N1) (○H) z, deposits on the surface, and then changes to an oxide layer due to dehydration reaction.An oxide film is formed by the wet corrosion reaction process, but at temperatures above 260°C, the stainless steel surface We discovered that the process of forming an oxide layer is mainly due to the dissolved oxygen in the water adsorbed and dissociated by the stainless steel directly diffusing into the interior of the stainless steel.
The present invention has been accomplished.
本発明の特徴は、ステンレス鋼表面を酸素の吸着・解離
反応に対してより活性な表面に改質した後、高温・酸化
性雰囲気中で腐食抑制に有効な酸化皮膜を加速形成させ
ることにある。The feature of the present invention is that after modifying the stainless steel surface to make it more active against oxygen adsorption and dissociation reactions, it accelerates the formation of an oxide film that is effective in inhibiting corrosion in high-temperature, oxidizing atmospheres. .
以下１本発明の基本的な実施例１を第１図により説明す
る。Below, a basic embodiment 1 of the present invention will be explained with reference to FIG.
実施例１
第１図では、原子炉組み立て前のステレス鋼配管部品を
例にとり、この配管の内面に、工場での加工処理過程で
、腐食抑制に有効な酸化皮膜を加速形成するための一実
施例を示した。第１図（ａ）は配管内面の改質過程、（
ｂ）は酸化皮膜の加速形成過程である。Example 1 Figure 1 shows an example of stainless steel piping parts before assembly of a nuclear reactor, and an example of how to accelerate the formation of an oxide film, which is effective in suppressing corrosion, on the inner surface of the piping during processing at a factory. An example was given. Figure 1(a) shows the reforming process on the inner surface of the pipe (
b) is an accelerated formation process of an oxide film.
第１図（ａ）において、１はステンレス鋼配管、２はＩ
Ｎの硫酸銀溶液、３は白金線、４は定電位電解装置、５
は電気絶縁性シールぶた、６は電気絶縁性スペーサーで
ある。今、室温下において、ステンレス鋼配管１と白金
３３の１１１に、定電位電解装置により、電位を加え、
ステンレス鋼配管内面をアノード分極させると、約０．
２ｖ（水素電極基準）以上で不動態化が起り、ステンレ
ス鋼配管内面にＡｇイオンを含む薄い酸化皮膜が形成さ
れる。形成される酸化皮膜厚さは、分極電位の増加と共
に厚くなり、約１，８ｖで最大となるａｌ、８Ｖで１時
間保持することによってステンレス鋼配管内面に形成さ
れるＡｇイオンを含む薄い酸化皮膜の安定化をはかった
。その後、第１図（ｂ）の方法で配管内面に酸化皮膜を
加速形成させた６第１図（ｂ）において、７は、耐熱耐
圧のステンレス製シール、８は溶存酸素を含む高温中性
純水、９は高温水循環ライン、１０は熱交換器、１１は
保圧弁、１２は溶存酸素濃度調整装置、１３は昇圧ポン
プ、１４は水温制御装置である。In Fig. 1(a), 1 is stainless steel piping, 2 is I
N silver sulfate solution, 3 platinum wire, 4 constant potential electrolyzer, 5
6 is an electrically insulating seal lid, and 6 is an electrically insulating spacer. Now, at room temperature, a potential is applied to stainless steel pipe 1 and platinum 33 111 using a constant potential electrolyzer,
When the inner surface of stainless steel piping is anodically polarized, approximately 0.
Passivation occurs at 2V (reference to hydrogen electrode) or higher, and a thin oxide film containing Ag ions is formed on the inner surface of the stainless steel pipe. The thickness of the oxide film that is formed increases as the polarization potential increases, reaching a maximum at about 1.8V.A thin oxide film containing Ag ions is formed on the inner surface of stainless steel piping by holding the voltage at 8V for 1 hour. aimed at stabilizing the After that, an oxide film was acceleratedly formed on the inner surface of the pipe by the method shown in Fig. 1 (b). 6 In Fig. 1 (b), 7 is a heat-resistant and pressure-resistant stainless steel seal, and 8 is a high-temperature neutral pure water containing dissolved oxygen. 9 is a high-temperature water circulation line, 10 is a heat exchanger, 11 is a pressure holding valve, 12 is a dissolved oxygen concentration adjustment device, 13 is a pressure pump, and 14 is a water temperature control device.
今、第１図（ａ）で表面改質を行った配管１の内部に、
第１図（ｂ）の装置を用いて、水温２００〜２９０℃、
溶存酸素２０〜１０００ｐ ｐ ｂの範囲で水質を変化
させ、それぞれ２４時間の高温水中酸化処理を行った。Now, inside the pipe 1 whose surface has been modified as shown in Fig. 1(a),
Using the apparatus shown in Fig. 1(b), water temperature is 200 to 290°C,
The water quality was varied in the range of 20 to 1000 ppb of dissolved oxygen, and high-temperature underwater oxidation treatment was performed for 24 hours.
得られた配管の腐食速度を各酸化処理条件下で測定し、
第１図（ａ）での表面改質を実施しない場合と比較して
第２図に示した。The corrosion rate of the resulting piping was measured under each oxidation treatment condition,
A comparison is shown in FIG. 2 with the case in which no surface modification was performed in FIG. 1(a).
第２図から明らかなように、腐食速度の温度依存性に変
曲点が表われる温度は１表面改質をすることにより、約
３０℃低温側にシフトし、２３０℃付近の低温側におい
ても、溶存酸素の吸着・解離が促進され、母材中への酸
素拡散による酸化皮膜形成が起るようになる。また、２
３０℃以上の高温下では、溶存酸素濃度の増加と共に腐
食速度の低減効果を顕著になる。ＨＭＡによる表面分析
の結果、酸化皮膜厚さが溶存酸素濃度の増加と共に母材
の内面方向に厚くなり、１０００ｐ ｐ ｂでは、２０
ｐｐｂに比べて約１．５倍、また、表面改質を行わない
場合に比べて約２．５倍になっていることが確認された
。さらに１０００ｐ Ｐ ｂ、２４時間の皮膜厚さは、
表面改質を行わない、２００ｐｐｂｙ１０００時間の皮
膜厚さに相当し、皮膜形成速度が約１１５０に加速され
ることがわかった。As is clear from Figure 2, the temperature at which the inflection point appears in the temperature dependence of the corrosion rate shifts to the lower side by about 30°C by performing one surface modification, and even at the low temperature side of around 230°C. , adsorption and dissociation of dissolved oxygen is promoted, and oxide film formation occurs due to oxygen diffusion into the base material. Also, 2
At high temperatures of 30° C. or higher, the effect of reducing the corrosion rate becomes significant as the dissolved oxygen concentration increases. As a result of surface analysis using HMA, the thickness of the oxide film increases toward the inner surface of the base material as the dissolved oxygen concentration increases, and at 1000 p p b, the thickness of the oxide film increases by 20
It was confirmed that the amount was about 1.5 times that of ppb, and about 2.5 times that of the case where no surface modification was performed. Furthermore, the film thickness at 1000 p P b for 24 hours is
It was found that without surface modification, the film formation rate was accelerated to about 1150, corresponding to a film thickness of 200 pp by 1000 hours.
実施例２
上記実施例では１表面改質の際の電解液として硫酸銀溶
液を用いたが、銀の硝酸塩、銀以外の硫酸、硝酸塩を用
いることも可能である。銀以外の金属としては、鉄より
も酸素に対する親和性が小さく、かつ酸素を固溶しやす
いものであればよく、例えば、銅、ニッケル等の硫酸、
硝酸塩を用いても同様の効果が発揮される。Example 2 In the above example, a silver sulfate solution was used as the electrolytic solution in surface modification 1, but it is also possible to use silver nitrate, sulfuric acid or nitrate other than silver. Metals other than silver may be metals as long as they have a lower affinity for oxygen than iron and can easily dissolve oxygen, such as copper, sulfuric acid such as nickel,
Similar effects can be achieved using nitrates.
実施例３
上記実施例では、アノード分極電位として、第３図に示
す分極曲線の不動態化電位域Ａの上限値を用いたが、不
動態化電位域の他の電位でアノード分極しても同様の効
果が得られる。しかし、不動態皮膜の膜厚が電位の上昇
と共に厚くなり、それに伴って高温水中における初期腐
食速度が小さくなることから５表面改質後の高温水中で
の酸化皮膜形成時間が短縮される傾向がある。また、通
年動態化電位域Ｂの電位を用いた場合、表面層からクロ
ムが選択溶出して、不動態皮膜中のクロムの割合が低下
するが、皮膜厚さは不動態化電位域に比べて、さらに厚
くなる。このような表面改質を行ったステンレス鋼では
、高温水中における初期腐食速度が、不動態化電位域で
表面改質した場合に比べて１．２〜１．５倍に増加する
が、その後の酸化皮膜形成速度が１．５〜２倍になるた
め、結果的に、より短時間で必要な酸化皮膜の形成が可
能である。Example 3 In the above example, the upper limit of the passivation potential range A of the polarization curve shown in FIG. 3 was used as the anode polarization potential. A similar effect can be obtained. However, the thickness of the passive film increases as the potential increases, and the initial corrosion rate in high-temperature water decreases accordingly, so the time required to form an oxide film in high-temperature water after surface modification tends to be shortened. be. In addition, when a potential in the year-round passivation potential range B is used, chromium is selectively eluted from the surface layer and the proportion of chromium in the passive film decreases, but the film thickness is smaller than that in the passivation potential range. , becomes even thicker. For stainless steel that has undergone such surface modification, the initial corrosion rate in high-temperature water increases by 1.2 to 1.5 times compared to when the surface is modified in the passivation potential range, but the subsequent Since the oxide film formation rate is increased by 1.5 to 2 times, it is possible to form the necessary oxide film in a shorter time as a result.
実施例４
上記実施例では、表面改質方法として、電気化学的手法
により、酸素の吸着・解離に対して活性な金属をイオン
の形で取り込ませたが、ステンレス鋼表面に直接、銀、
銅、ニッケル等の金属薄膜を形成させても、同様の効果
を生じさせることができる６ｇ膜の形成方法としては、
メッキ法、蒸着法、スパッタリング法等の従来の技術を
そのまま活用することができる。５０〜５００人の薄膜
を形成させたステンレス鋼板を高温水中で酸化処理する
と、陽極酸化の場合とほぼ同様の酸化皮膜形成加速効果
が得られる。薄膜の厚さが厚くなりすぎると、母材表面
に形成されるステンレス鋼酸化物層と、事前に形成させ
た金／ｉ１薄膜酸化物層での体積膨張率の差によって、
金属薄膜酸化物層がはく離し易くなり、その後のステン
レス鋼酸化物層の成長加速効果が著しく低下する。また
、上記のような薄膜形成手法を、原子カプラントで用い
られる配管内面に適用することは実用性に欠ける。Example 4 In the above example, as a surface modification method, a metal active in the adsorption and dissociation of oxygen was incorporated in the form of ions using an electrochemical method.
A method for forming a 6g film that can produce the same effect even when a thin metal film of copper, nickel, etc. is formed is as follows.
Conventional techniques such as plating, vapor deposition, and sputtering can be used as they are. When a stainless steel plate on which a 50 to 500 thin film has been formed is oxidized in high-temperature water, an effect of accelerating the formation of an oxide film almost the same as in the case of anodic oxidation can be obtained. If the thickness of the thin film becomes too thick, the difference in volumetric expansion between the stainless steel oxide layer formed on the surface of the base material and the gold/i1 thin film oxide layer formed in advance causes
The metal thin film oxide layer is likely to peel off, and the subsequent growth acceleration effect of the stainless steel oxide layer is significantly reduced. Further, it is impractical to apply the above-mentioned thin film forming method to the inner surface of a pipe used in an atomic couplant.
実施例５
上記実施例では、ステンレス鋼配管内面の表面改質処理
を行った後、高温水中で酸化処理することにより必要な
酸化皮膜を加速形成させたが、原子カプラントへの適用
に当っては、工場段階で表面改質処理を行った配管を用
いて、プラント建設後起動試運転時に必要な酸化皮膜を
加速形成させることも可能である。この場合、従来の表
面改質処理を実施しない場合に比べて、プラントでの熱
処理時間が約１１５０に短縮される。Example 5 In the above example, the inner surface of the stainless steel pipe was surface-modified and then oxidized in high-temperature water to accelerate the formation of the necessary oxide film. It is also possible to accelerate the formation of the oxide film required during start-up test runs after plant construction by using piping that has undergone surface modification treatment at the factory stage. In this case, the heat treatment time in the plant is shortened to about 1150 minutes compared to the case where conventional surface modification treatment is not performed.
第１図は本発明を実施するのに適した、処理装置の具体
的な構成図、第２図は本発明の実施効果を定量的に示す
線図、第３図は本発明の別の実施例におけるアノード分
極操作条件を示す線図である。
１・・・ステンレス鋼配管、２・・・ＩＮの硫酸銀溶液
、３・・・白金線、４・・・定電位電解装置、９・・・
高温水循環ライン、１０・・・熱交換器、１１・・・保
圧弁、１３・・・昇圧ポンプ、１４・・・水温制御装置
。Fig. 1 is a specific configuration diagram of a processing device suitable for implementing the present invention, Fig. 2 is a diagram quantitatively showing the effect of implementing the present invention, and Fig. 3 is another embodiment of the present invention. FIG. 3 is a diagram showing anode polarization operating conditions in an example. DESCRIPTION OF SYMBOLS 1... Stainless steel piping, 2... IN silver sulfate solution, 3... Platinum wire, 4... Constant potential electrolyzer, 9...
High temperature water circulation line, 10... Heat exchanger, 11... Pressure holding valve, 13... Boosting pump, 14... Water temperature control device.
Claims (1)
より活性な表面に改質した後、高温・酸化性雰囲気中で
腐食抑制に有効な酸化皮膜を加速形成させることを特徴
とする前酸化処理方法。1. Pre-oxidation, which is characterized by modifying the stainless steel surface to make it more active against oxygen adsorption and dissociation reactions, and then accelerating the formation of an oxide film that is effective in inhibiting corrosion in a high-temperature, oxidizing atmosphere. Processing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61017956A JPS62177492A (en) | 1986-01-31 | 1986-01-31 | Pre-oxidation treatment method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61017956A JPS62177492A (en) | 1986-01-31 | 1986-01-31 | Pre-oxidation treatment method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62177492A true JPS62177492A (en) | 1987-08-04 |
Family
ID=11958200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61017956A Pending JPS62177492A (en) | 1986-01-31 | 1986-01-31 | Pre-oxidation treatment method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62177492A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4940564A (en) * | 1986-10-20 | 1990-07-10 | Hitachi, Ltd. | Suppression of deposition of radioactive substances in boiling water type, nuclear power plant |
| CN105716919A (en) * | 2016-02-22 | 2016-06-29 | 苏州热工研究院有限公司 | Preparation method of stainless steel performed oxide film sample with radionuclide |
-
1986
- 1986-01-31 JP JP61017956A patent/JPS62177492A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4940564A (en) * | 1986-10-20 | 1990-07-10 | Hitachi, Ltd. | Suppression of deposition of radioactive substances in boiling water type, nuclear power plant |
| CN105716919A (en) * | 2016-02-22 | 2016-06-29 | 苏州热工研究院有限公司 | Preparation method of stainless steel performed oxide film sample with radionuclide |
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