JPH04280955A - Method for modifying surface of chromizing steel - Google Patents
Method for modifying surface of chromizing steelInfo
- Publication number
- JPH04280955A JPH04280955A JP6918091A JP6918091A JPH04280955A JP H04280955 A JPH04280955 A JP H04280955A JP 6918091 A JP6918091 A JP 6918091A JP 6918091 A JP6918091 A JP 6918091A JP H04280955 A JPH04280955 A JP H04280955A
- Authority
- JP
- Japan
- Prior art keywords
- chromizing
- steel
- surface modification
- chromium
- steel according
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 36
- 239000010959 steel Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000005254 chromizing Methods 0.000 title claims abstract description 25
- UFGZSIPAQKLCGR-UHFFFAOYSA-N chromium carbide Chemical compound [Cr]#C[Cr]C#[Cr] UFGZSIPAQKLCGR-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 22
- 229910003470 tongbaite Inorganic materials 0.000 claims abstract description 22
- 239000002344 surface layer Substances 0.000 claims abstract description 15
- 239000011261 inert gas Substances 0.000 claims abstract description 7
- 239000000463 material Substances 0.000 claims description 34
- 230000004048 modification Effects 0.000 claims description 15
- 238000012986 modification Methods 0.000 claims description 15
- 238000005260 corrosion Methods 0.000 abstract description 19
- 230000007797 corrosion Effects 0.000 abstract description 19
- 229910001209 Low-carbon steel Inorganic materials 0.000 abstract description 5
- 238000004381 surface treatment Methods 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 18
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 15
- 229910052804 chromium Inorganic materials 0.000 description 14
- 239000011651 chromium Substances 0.000 description 14
- 238000010586 diagram Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 239000012611 container material Substances 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 229910020275 Na2Sx Inorganic materials 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- XZXYQEHISUMZAT-UHFFFAOYSA-N 2-[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol Chemical compound CC1=CC=C(O)C(CC=2C(=CC=C(C)C=2)O)=C1 XZXYQEHISUMZAT-UHFFFAOYSA-N 0.000 description 2
- 229910019589 Cr—Fe Inorganic materials 0.000 description 2
- 229910014103 Na-S Inorganic materials 0.000 description 2
- 229910014147 Na—S Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229940107816 ammonium iodide Drugs 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000002715 modification method Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- BNOODXBBXFZASF-UHFFFAOYSA-N [Na].[S] Chemical compound [Na].[S] BNOODXBBXFZASF-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- -1 composed of Cr2C Chemical compound 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- HYHCSLBZRBJJCH-UHFFFAOYSA-N sodium polysulfide Chemical compound [Na+].S HYHCSLBZRBJJCH-UHFFFAOYSA-N 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000005486 sulfidation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Physical Vapour Deposition (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、ナトリウム−硫黄電池
の陽極容器材等に用いるクロマイジング鋼の表面改質方
法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for surface modification of chromizing steel used as anode container materials for sodium-sulfur batteries.
【０００２】0002
【従来の技術】Ｎａ−ｓ電池の陽極容器材は、電池の放
電時に生成する腐食性の強い多硫化ナトリウム（以下、
Ｎａ２Ｓｘと称す）に対して一定期間の腐食性をもつこ
とが要求される。[Prior Art] The anode container material for Na-S batteries is made of highly corrosive sodium polysulfide (hereinafter referred to as
(referred to as Na2Sx) for a certain period of time.
【０００３】従来は、陽極容器材として用いる鋼表面に
低圧でＣｒ，Ｃｒ−Ｆｅ合金及びＴｉＮなどを溶射する
方法が溶射層を簡単に厚肉化でき、かつ比較的安価であ
るが、溶射層が粗であるため、溶融Ｎａ２Ｓｘ中では耐
食性がよくない。またクロム及びモリブデンの単体金属
、ステンレス鋼（ＳＵＳ−３４７）及びクロムメッキな
ども電池寿命を満足できる耐食性がない。一方、クロマ
イジング鋼は電池陽極容器材として推奨されているが、
従来材のクロマイジング鋼は、表面層側に５〜１０μｍ
のクロム富化層と、その内側にクロム拡散層（クロム−
鉄合金層）とが２０〜１００μｍ存在し、母材（一般に
は低炭素鋼材）を含めて３層構造となっている。なおク
ロム富化層は、Ｃｒ２Ｃ形の炭化物を主成分とした数種
のクロム炭化物が形成され、このクロム炭化物層により
耐食性を持たせるものである。これらの金属材料の耐食
性は、接液部の化学的安定性、母材との密着性、平滑（
凹凸が少ないこと）及び緻密（無気孔、または気孔が少
ないこと）であることが重要なポイントとなる。従来材
のクロマイジング法は、クロム粉末２０％、アルミナ５
８％によう化アンモニウム２％を添加した混合粉末を、
電気炉床中に入れるとともに被処理材を入れ、水素気流
中で加熱処理を行って被処理材表面にクロムを拡散させ
る。このため密着性はよいが、表面形状はうねり状の凹
凸及びメッシュ（ポ−ラス）状部に粒子状部が点在する
形態が形成され、これらの形状部が起点となって孔食が
発生し、腐食が拡大する可能性がある。Ｎａ−Ｓ電池は
作動温度約３５０℃で用いられるため、電池の放電時に
生成されるＮａ２Ｓｘは、当然液体であり、電池陽極容
器材であるクロマイジング鋼表面がポ−ラスであること
は、このポ−ラス部にＮａ２Ｓｘが侵入して腐食するこ
と、及び凹凸部において局部電池が形成され孔食が発生
して腐食を拡大するため、電池の寿命を短くする原因と
なっている。また、これまでに、従来材はメッシュ形状
の方が硫化による腐食速度が早いことが知られており、
メッシュ（ポ−ラス）状部は粒子状部より化学組性が科
学的に不安定なクロム炭化物（Ｃｒ２Ｃ）のためである
。Conventionally, the method of thermally spraying Cr, Cr-Fe alloy, TiN, etc. at low pressure onto the steel surface used as the anode container material has been used to easily increase the thickness of the thermally sprayed layer and is relatively inexpensive. Since it is coarse, its corrosion resistance is poor in molten Na2Sx. Furthermore, single metals such as chromium and molybdenum, stainless steel (SUS-347), and chrome plating do not have corrosion resistance that can satisfy battery life. On the other hand, chromizing steel is recommended as a battery anode container material, but
Conventional chromizing steel has a thickness of 5 to 10 μm on the surface layer side.
chromium-enriched layer and a chromium-diffused layer (chromium-
The iron alloy layer) is present in a thickness of 20 to 100 μm, and has a three-layer structure including the base material (generally low carbon steel material). The chromium-enriched layer is formed of several types of chromium carbide mainly composed of Cr2C type carbide, and this chromium carbide layer provides corrosion resistance. The corrosion resistance of these metal materials is determined by the chemical stability of the parts in contact with liquid, the adhesion to the base material, and the smoothness (
The important points are that the material has few irregularities) and is dense (no pores or few pores). The chromizing method for conventional materials uses 20% chromium powder and 5% alumina.
A mixed powder of 8% ammonium iodide and 2% ammonium iodide,
The material to be treated is placed in an electric hearth and the material to be treated is heated in a hydrogen stream to diffuse chromium onto the surface of the material to be treated. For this reason, adhesion is good, but the surface shape has undulations and convexities and mesh (porous) parts dotted with particulate parts, and pitting corrosion occurs from these shaped parts. However, corrosion may spread. Since Na-S batteries are used at an operating temperature of approximately 350°C, the Na2Sx generated during battery discharge is naturally liquid, and the porous surface of the chromized steel that is the battery anode container material is one reason for this. Na2Sx invades and corrodes the porous portions, and local batteries are formed in the uneven portions, causing pitting corrosion and expanding the corrosion, resulting in a shortened battery life. In addition, it has been known that conventional materials with a mesh shape corrode at a faster rate due to sulfidation.
The mesh (porous) part is made of chromium carbide (Cr2C), which has a chemical composition that is chemically more unstable than that of the particulate part.
【０００４】公知例として特開昭６３−１９２８５４号
公報に、金属の表面にクロマイズ処理した後、侵炭雰囲
気中で９００℃、１時間加熱し、表面硬度を高めて耐摩
耗性を向上する処理方法、また特開昭６１−１９４１７
０号公報にはクロムメッキを施した表面部に、真空中又
は非酸化雰囲気中で拡散処理を施し、耐高温酸化性、耐
摩耗性の表面層を形成する処理方法が記載されているが
、耐食性を向上する表面改質方法ではなく、さらに特開
昭６３−２５０４５２号公報に、管内に浸透剤を充填し
回転しながらＮ２ガス中でクロマイズ処理する方法が記
載されているが、表面層厚の分布を均一にするもので、
クロマイズ処理そのものの改善である。As a known example, JP-A-63-192854 discloses a treatment in which the surface of a metal is chromized and then heated at 900°C for 1 hour in a carburizing atmosphere to increase surface hardness and improve wear resistance. method, and Japanese Patent Application Laid-Open No. 61-19417
Publication No. 0 describes a treatment method in which a chromium-plated surface is subjected to a diffusion treatment in a vacuum or in a non-oxidizing atmosphere to form a high-temperature oxidation-resistant and abrasion-resistant surface layer. Rather than a surface modification method that improves corrosion resistance, JP-A-63-250452 describes a method in which a penetrant is filled into a pipe and chromized in N2 gas while rotating, but the surface layer thickness It makes the distribution of
This is an improvement to the chromization process itself.
【０００５】[0005]
【発明が解決しようとする課題】従来のクロマイジング
処理方法に依るクロマイジング鋼は、表面層に凹凸やポ
−ラス部が形成され、それらが起点となってくる孔食が
発生し、腐食が拡大する問題点があった。[Problems to be Solved by the Invention] Chromized steel produced by conventional chromizing treatment methods has unevenness and porous parts formed on the surface layer, which causes pitting corrosion and corrosion. There was a growing problem.
【０００６】本発明の目的は、クロマイジング鋼の表面
層を緻密で平滑に形成するとともに、クロム炭化物を科
学的に安定な単一種（Ｃｒ２３Ｃ６）に変えて耐食性を
向上させたクロマイジング鋼の表面改質方法を提供する
ことにある。The object of the present invention is to form a dense and smooth surface layer of chromized steel, and to improve corrosion resistance by changing chromium carbide to a single chemically stable species (Cr23C6). The object of the present invention is to provide a reforming method.
【０００７】[0007]
【課題を解決するための手段】前記目的を達成するため
、本発明に係るクロマイジング鋼の表面改質方法は、鋼
材をクロマイジング法で表面処理した後、真空または不
活性ガスの雰囲気中で加熱処理し、表面層のメッシュ形
状を緻密に改質させる構成とする。[Means for Solving the Problems] In order to achieve the above object, the method for surface modification of chromizing steel according to the present invention includes surface-treating a steel material by a chromizing method, and then treating the steel material in a vacuum or an inert gas atmosphere. The structure is such that the mesh shape of the surface layer is precisely modified by heat treatment.
【０００８】そして表面層は、平滑に改質される構成で
もよい。[0008] The surface layer may be modified to be smooth.
【０００９】また表面層は、クロム炭化物がＣｒ２３Ｃ
６形の単一種のクロム炭化物に改質される構成でもよい
。[0009] Furthermore, in the surface layer, the chromium carbide is Cr23C.
A structure in which the chromium carbide is modified into a single type of chromium carbide of Type 6 may be used.
【００１０】さらに加熱処理は、真空度１／１０４Ｔｏ
ｒｒ以上の雰囲気中で１１２５〜１１７５℃の加熱温度
に１．５〜２．５時間保持して行なわれる構成とする。[0010] Furthermore, the heat treatment is carried out at a vacuum degree of 1/104 To
The heating temperature is maintained at 1125 to 1175° C. for 1.5 to 2.5 hours in an atmosphere of rr or higher.
【００１１】そして、加熱処理は、真空度１／１０５Ｔ
ｏｒｒの雰囲気中で１１５０℃の加熱温度に２．５時間
保持して行なわれる構成でもよい。[0011]Then, the heat treatment is performed at a vacuum degree of 1/105T.
The heating temperature may be maintained at 1150° C. for 2.5 hours in an atmosphere of 1,150° C. orr.
【００１２】また、ボイラの伝熱管、高速増殖炉用蒸発
器の伝熱管及び高速増殖炉用制御棒においては、、請求
項１〜５のいずれか１項記載のクロマイジング鋼の表面
改質方法を用いて処理される構成とする。[0012] Furthermore, in heat exchanger tubes of boilers, heat exchanger tubes of evaporators for fast breeder reactors, and control rods for fast breeder reactors, the method for surface modification of chromized steel according to any one of claims 1 to 5 is used. The configuration is configured to be processed using .
【００１３】[0013]
【作用】本発明のクロマイジング鋼の表面改質方法によ
れば、クロマイジング鋼を高真空中で一定時間、加熱処
理することにより、クロマイジング鋼表面が緻密で平滑
になり、しかも化学的に安定なクロム炭化物が形成され
て耐食性が向上する。[Function] According to the method for surface modification of chromizing steel of the present invention, by heat-treating the chromizing steel in a high vacuum for a certain period of time, the surface of the chromizing steel becomes dense and smooth, and chemically Stable chromium carbide is formed and corrosion resistance is improved.
【００１４】また、加熱処理の雰囲気は、高純度のアル
ゴンガス及びヘリウムガス中でも目的の表面処理が可能
である。[0014] Furthermore, the desired surface treatment can be carried out even in a heat treatment atmosphere of high purity argon gas or helium gas.
【００１５】そして加熱処理条件は、加熱温度１１２５
〜１１７５℃で加熱時間２．５ｈが最も好ましいが、加
熱温度を高くした場合は加熱時間は短く、逆に加熱温度
を低くした場合は加熱時間を長くすることにより、目的
の表面形状が得られる。[0015] The heat treatment conditions include a heating temperature of 1125
A heating time of 2.5 hours at ~1175°C is most preferable, but the desired surface shape can be obtained by increasing the heating temperature, shortening the heating time, and conversely, by increasing the heating time if the heating temperature is lowered. .
【００１６】[0016]
【実施例】本発明の一実施例を図１を参照しながら説明
する。[Embodiment] An embodiment of the present invention will be described with reference to FIG.
【００１７】図１に示すように、まず、素材（母材）で
ある低炭素鋼材１０を、クロム２０％、アルミナ５８％
の混合粉末に２％のよう化アンモニウムを添加した電気
炉床中に入れ、１１５０℃で２時間（ｈ）の処理をＨ２
ガス中で行ない、クロマイジング鋼を作成する。As shown in FIG. 1, first, a low carbon steel material 10 which is a material (base material) is mixed with 20% chromium and 58% alumina.
A mixed powder of
Performed in gas to create chromized steel.
【００１８】本発明は、このクロマイジング鋼を電気炉
中において、真空度１／１０４Ｔｏｒｒ以上の真空また
は不活性ガス雰囲気中で１１２５〜１１７５℃の温度で
１．５〜２．５時間の加熱処理、又は真空度１／１０５
Ｔｏｒｒの真空または不活性ガス雰囲気中で１１５０℃
の温度で２．５時間の加熱処理を施し、クロマイジング
鋼の表面改質材１１を製作するように構成されている。[0018] The present invention heat-treats the chromized steel in an electric furnace at a temperature of 1125 to 1175°C for 1.5 to 2.5 hours in a vacuum with a degree of vacuum of 1/104 Torr or higher or in an inert gas atmosphere. , or degree of vacuum 1/105
1150℃ in Torr vacuum or inert gas atmosphere
The structure is such that a heat treatment is performed at a temperature of 2.5 hours to produce a surface-modified material 11 of chromizing steel.
【００１９】図２は、図１の工程によって製作した本発
明による熱処理材（表面改質材）の表面形状（ＳＥＭ二
次電子像を示す粒子構造の写真であり、図３はその表面
のＸ線回析を行なった図である。表面のＣｒ２３Ｃ６形
炭化物の結晶組織１は、回析ピ−ク２により全てＣｒ２
３Ｃ６形のクロム炭化物であることがわかる。FIG. 2 is a photograph of the particle structure showing the surface shape (SEM secondary electron image) of the heat-treated material (surface-modified material) according to the present invention produced by the process shown in FIG. 1, and FIG. It is a diagram obtained by performing line diffraction.The crystal structure 1 of the Cr23C6 type carbide on the surface is entirely Cr2 due to the diffraction peak 2.
It can be seen that it is a 3C6 type chromium carbide.
【００２０】図４は従来のクロマイジング鋼の表面形状
（ＳＥＭ二次電子像）を示す粒子構造の写真であり、図
５はその表面のＸ線回析を行なった図である。FIG. 4 is a photograph of the grain structure showing the surface shape (SEM secondary electron image) of a conventional chromized steel, and FIG. 5 is a diagram showing the X-ray diffraction of the surface.
【００２１】図４に従来のクロマイジング鋼の表面形態
３、Ｃｒ２Ｃを主成分としたクロム炭化物から成るメッ
シュ（ポ−ラス）形状４、メッシュ形状４の地の中に点
在するＣｒ２３Ｃ６形のクロム炭化物５が示され、第５
図に従来のクロマイジング鋼表面のＸ線回析結果６が示
される。Ｒと示してあるピ−クはＣｒ２３Ｃ６であり、
Ｃと示してあるピ−クはＣｒ２Ｃ形のクロム炭化物種で
あり、Ｃｒ２Ｃ形のクロム炭化物種であり、Ｃｒ２Ｃ形
種の方が約６：４の割合で多く存在している。FIG. 4 shows the surface morphology 3 of conventional chromizing steel, a mesh (porous) shape 4 made of chromium carbide mainly composed of Cr2C, and Cr23C6 type chromium dotted in the ground of the mesh shape 4. Carbide 5 is shown and the fifth
The figure shows X-ray diffraction results 6 for the surface of conventional chromizing steel. The peak marked R is Cr23C6,
The peak labeled C is a Cr2C type chromium carbide species, and the Cr2C type species is present in a larger amount at a ratio of about 6:4.
【００２２】図６は本発明による表面改質材の断面のミ
クロ組織写真である。クロム富化層７は、Ｃｒ２３Ｃ６
形のクロム炭化物層で化学的に安定し耐食性が高く、ク
ロム拡散層８はＣｒ−Ｆｅ合金層であり、母材９は低炭
素鋼材を示し、きれいな３層構造を形成している。FIG. 6 is a cross-sectional microstructure photograph of the surface-modified material according to the present invention. The chromium-enriched layer 7 is Cr23C6
The chromium diffusion layer 8 is a Cr-Fe alloy layer, and the base material 9 is a low carbon steel material, forming a clean three-layer structure.
【００２３】図７は従来材及び本発明による表面改質材
の断面におけるクロム富化層、及びクロム拡散層厚さ、
並びに表面粗さの測定結果である。FIG. 7 shows the thickness of the chromium-enriched layer and the chromium-diffused layer in the cross-sections of the conventional material and the surface-modified material according to the present invention.
and the measurement results of surface roughness.
【００２４】本発明によれば、従来材の表面形状が緻密
、平滑及び化学的に安定なＣｒ２３Ｃ６形の炭化物に改
質され、十分な耐食性向上が期待できる。According to the present invention, the surface shape of the conventional material is modified into a dense, smooth, and chemically stable Cr23C6 type carbide, and a sufficient improvement in corrosion resistance can be expected.
【００２５】図７に示すように、従来材を熱処理するこ
とによって、クロム富化層厚さは、僅か（約１μｍ）に
薄くなっているが、表面粗さは０．３μｍ平滑化された
。すなわち、図１及び図７を合せてみると従来材の表面
改質ができていることがわかる。As shown in FIG. 7, by heat-treating the conventional material, the thickness of the chromium-enriched layer was slightly reduced (about 1 μm), but the surface roughness was smoothed by 0.3 μm. That is, when FIGS. 1 and 7 are combined, it can be seen that the surface of the conventional material has been modified.
【００２６】なお、図７では、クロム拡散層が従来材の
約２倍となっている。この結果から、クロム炭化物にお
ける高耐食性を保持するのは、クロム富化層であるが、
クロム富化層が腐食されてしまった場合は、このクロム
拡散層が腐食の進行を緩和する役目をする有効な形態と
なっている。Note that in FIG. 7, the chromium diffusion layer is approximately twice as large as that of the conventional material. From this result, it is the chromium-enriched layer that maintains high corrosion resistance in chromium carbide, but
If the chromium-enriched layer is corroded, this chromium-diffused layer is an effective form of mitigation of the progress of corrosion.
【００２７】本発明は、従来材のクロマイジング鋼を真
空中で一定時間高温で加熱処理することにより、クロマ
イジング鋼の表面層を緻密、平滑及び化学的に安定なク
ロム炭化物組成に簡単に改質することができるクロマイ
ジング鋼の表面改質方法であって、アルゴンガス、また
はヘリウムガスなどの不活性ガスの雰囲気中で加熱温度
及び加熱時間を変えることによっても前記目的を達成で
きる。[0027] The present invention allows the surface layer of chromized steel to be easily modified into a dense, smooth, and chemically stable chromium carbide composition by heat-treating conventional chromized steel at high temperature for a certain period of time in a vacuum. The above object can also be achieved by changing the heating temperature and heating time in an atmosphere of an inert gas such as argon gas or helium gas.
【００２８】さらに本発明は、Ｎａ冷却型高速増殖炉の
蒸気発生器用伝熱管に適用して水側より拡散する水素の
抑制ができるとともに、ボイラの伝熱管材などにも適用
できる。Furthermore, the present invention can be applied to heat exchanger tubes for steam generators of Na-cooled fast breeder reactors to suppress hydrogen diffusing from the water side, and can also be applied to heat exchanger tube materials for boilers.
【００２９】そして高速増殖炉用制御棒を本発明により
改質することによって、電磁石とア−マチュアとの接触
面のかじりを防止することができる。By modifying the control rod for a fast breeder reactor according to the present invention, galling of the contact surface between the electromagnet and the armature can be prevented.
【００３０】[0030]
【発明の効果】本発明のクロマイジング鋼の表面改質方
法によれば、耐食材としての基本条件である接液部の化
学的安定性、平滑及び無気孔の３要素が、高真空中また
は不活性ガス中で高温の所定時間加熱処理を施すことに
よって、クロマイジング鋼の表面形態を容易に改質でき
、耐食性を飛躍的に向上できる。また、簡単な装置によ
り目的が達成でき、適用機器の長寿命化と、製作コスト
の低減とが図れる効果がある。[Effects of the Invention] According to the surface modification method of chromizing steel of the present invention, the three basic conditions for corrosion resistance, namely chemical stability, smoothness, and no porosity of the wetted part, can be achieved in a high vacuum or in a high vacuum. By performing heat treatment at a high temperature for a predetermined period of time in an inert gas, the surface morphology of the chromized steel can be easily modified and the corrosion resistance can be dramatically improved. Moreover, the purpose can be achieved with a simple device, and there is an effect that the life of the applied equipment can be extended and the manufacturing cost can be reduced.
【図１】本発明の一実施例を示す構成図である。FIG. 1 is a configuration diagram showing an embodiment of the present invention.
【図２】本発明による表面改質材の粒子構造を示す写真
である。FIG. 2 is a photograph showing the particle structure of the surface modification material according to the present invention.
【図３】図２のＸ線回析結果を示す図である。FIG. 3 is a diagram showing the X-ray diffraction results of FIG. 2.
【図４】従来材の粒子構造を示す写真である。FIG. 4 is a photograph showing the particle structure of a conventional material.
【図５】図４のＸ線回析結果を示す図である。FIG. 5 is a diagram showing the X-ray diffraction results of FIG. 4.
【図６】本発明による表面改質材の断面の金属組織を示
す写真である。FIG. 6 is a photograph showing the metal structure of a cross section of the surface-modified material according to the present invention.
【図７】従来材と表面改質材との比較を示す図である。FIG. 7 is a diagram showing a comparison between a conventional material and a surface-modified material.
１０ 低炭素鋼材 １１ 表面改質材 10 Low carbon steel 11 Surface modification material
Claims (8)
た後、真空または不活性ガスの雰囲気中で加熱処理し、
表面層のメッシュ形状を緻密に改質させることを特徴と
するクロマイジング鋼の表面改質方法。[Claim 1] After surface-treating the steel material by chromizing method, heat-treating it in a vacuum or an inert gas atmosphere,
A method for surface modification of chromizing steel characterized by closely modifying the mesh shape of the surface layer.
徴とする請求項１記載のクロマイジング鋼の表面改質方
法。2. The method of surface modification of chromizing steel according to claim 1, wherein the surface layer is modified to be smooth.
６形の単一種のクロム炭化物に改質されることを特徴と
する請求項１記載のクロマイジング鋼の表面改質方法。3. In the surface layer, the chromium carbide is Cr23C.
2. The method for surface modification of chromized steel according to claim 1, wherein the surface modification is performed to form a single type of chromium carbide of type 6.
ｒ以上の雰囲気中で１１２５〜１１７５℃の加熱温度に
１．５〜２．５時間保持して行なわれることを特徴とす
る請求項１記載のクロマイジング鋼の表面改質方法。4. The heat treatment is performed at a vacuum degree of 1/104 Torr.
2. The method for surface modification of chromized steel according to claim 1, wherein the method is carried out by holding the heating temperature at 1125 to 1175° C. for 1.5 to 2.5 hours in an atmosphere of at least r.
ｒの雰囲気中で１１５０℃の加熱温度に２．５時間保持
して行なわれることを特徴とする請求項１記載のクロマ
イジング鋼の表面改質方法。5. The heat treatment is performed at a vacuum degree of 1/105 Torr.
2. The method for surface modification of chromizing steel according to claim 1, wherein the method is carried out by holding the heating temperature at 1150° C. for 2.5 hours in an atmosphere of R.
ロマイジング鋼の表面改質方法を用いて処理したことを
特徴とするボイラの伝熱管。6. A heat exchanger tube for a boiler, characterized in that it has been treated using the method for surface modification of chromizing steel according to any one of claims 1 to 5.
ロマイジング鋼の表面改質方法を用いて処理したことを
特徴とする高速増殖炉用蒸発器の伝熱管。7. A heat exchanger tube for an evaporator for a fast breeder reactor, characterized in that it is treated using the method for surface modification of chromizing steel according to any one of claims 1 to 5.
ロマイジング鋼の表面改質方法を用いて処理したことを
特徴とする高速増殖炉用制御棒。8. A control rod for a fast breeder reactor, characterized in that it has been treated using the method for surface modification of chromizing steel according to any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6918091A JPH04280955A (en) | 1991-03-08 | 1991-03-08 | Method for modifying surface of chromizing steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6918091A JPH04280955A (en) | 1991-03-08 | 1991-03-08 | Method for modifying surface of chromizing steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04280955A true JPH04280955A (en) | 1992-10-06 |
Family
ID=13395268
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6918091A Pending JPH04280955A (en) | 1991-03-08 | 1991-03-08 | Method for modifying surface of chromizing steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04280955A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002092980A1 (en) * | 2001-05-10 | 2002-11-21 | Soghi Kogyo Co., Ltd. | Surface-reformed exhaust gas guide assembly of vgs type turbo charger, and method of surface-reforming component member thereof |
| US7205055B2 (en) | 2002-11-01 | 2007-04-17 | Honda Motor Co., Ltd. | High temperature oxidation resistant carbonaceous molding and manufacturing method thereof |
| JP2013127094A (en) * | 2011-12-19 | 2013-06-27 | Canon Inc | Method of manufacturing chromium nitride or chromium carbonitride, chromium nitride or chromium carbonitride, and vibration wave driving apparatus for using chromium nitride or chromium carbonitride |
| WO2017017708A1 (en) * | 2015-07-27 | 2017-02-02 | 株式会社 東芝 | Method for producing cobalt-base alloy member |
-
1991
- 1991-03-08 JP JP6918091A patent/JPH04280955A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002092980A1 (en) * | 2001-05-10 | 2002-11-21 | Soghi Kogyo Co., Ltd. | Surface-reformed exhaust gas guide assembly of vgs type turbo charger, and method of surface-reforming component member thereof |
| US7205055B2 (en) | 2002-11-01 | 2007-04-17 | Honda Motor Co., Ltd. | High temperature oxidation resistant carbonaceous molding and manufacturing method thereof |
| JP2013127094A (en) * | 2011-12-19 | 2013-06-27 | Canon Inc | Method of manufacturing chromium nitride or chromium carbonitride, chromium nitride or chromium carbonitride, and vibration wave driving apparatus for using chromium nitride or chromium carbonitride |
| WO2017017708A1 (en) * | 2015-07-27 | 2017-02-02 | 株式会社 東芝 | Method for producing cobalt-base alloy member |
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