JPS6240417B2 - - Google Patents
Info
- Publication number
- JPS6240417B2 JPS6240417B2 JP11092786A JP11092786A JPS6240417B2 JP S6240417 B2 JPS6240417 B2 JP S6240417B2 JP 11092786 A JP11092786 A JP 11092786A JP 11092786 A JP11092786 A JP 11092786A JP S6240417 B2 JPS6240417 B2 JP S6240417B2
- Authority
- JP
- Japan
- Prior art keywords
- atomic
- amorphous
- corrosion resistance
- alloy
- corrosion
- 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
- 238000005260 corrosion Methods 0.000 claims description 59
- 230000007797 corrosion Effects 0.000 claims description 59
- 229910052804 chromium Inorganic materials 0.000 claims description 22
- 229910000808 amorphous metal alloy Inorganic materials 0.000 claims description 21
- 229910052750 molybdenum Inorganic materials 0.000 claims description 20
- 229910052742 iron Inorganic materials 0.000 claims description 7
- 229910052752 metalloid Inorganic materials 0.000 claims description 7
- 150000002738 metalloids Chemical class 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 30
- 229910045601 alloy Inorganic materials 0.000 description 29
- 239000000956 alloy Substances 0.000 description 29
- 239000011651 chromium Substances 0.000 description 28
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 16
- 229910052710 silicon Inorganic materials 0.000 description 12
- 239000007864 aqueous solution Substances 0.000 description 11
- 239000000203 mixture Substances 0.000 description 10
- 229910000640 Fe alloy Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 229910052698 phosphorus Inorganic materials 0.000 description 8
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000011733 molybdenum Substances 0.000 description 6
- 238000002161 passivation Methods 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910000604 Ferrochrome Inorganic materials 0.000 description 3
- 229910001309 Ferromolybdenum Inorganic materials 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 229910052715 tantalum Inorganic materials 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 229910001021 Ferroalloy Inorganic materials 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- VQWFNAGFNGABOH-UHFFFAOYSA-K chromium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Cr+3] VQWFNAGFNGABOH-UHFFFAOYSA-K 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 229910017060 Fe Cr Inorganic materials 0.000 description 1
- 229910002544 Fe-Cr Inorganic materials 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910001182 Mo alloy Inorganic materials 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 229910000589 SAE 304 stainless steel Inorganic materials 0.000 description 1
- 229910008423 Si—B Inorganic materials 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- 101150059448 cdk7 gene Proteins 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910001256 stainless steel alloy Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Soft Magnetic Materials (AREA)
Description
本発明は超高耐食性アモルフアス合金に関する
ものであり、特に本発明は6NHCl程度あるいはそ
れ以上の腐食環境において耐食性をもつ超高耐食
性Fe−Cr−Mo系アモルフアス合金に関するもの
である。
従来、広く使われている通常の耐食性合金はス
テンレス合金、たとえば13％クロム鋼、18−８ス
テンレス鋼（304鋼）、17−14−2.5Moステンレス
鋼（316鋼）とか、ニツケル基合金などがあり、
耐候性、耐食性に優れている。しかし更に高腐食
性の環境たとえば、1N塩酸水溶液では不動態膜
が壊れて、従来の耐食性合金はほとんどすべて
が、孔食を受ける。
一方、本発明者らの一人はさきに特願昭49−
74246（特開昭51−4017）により、高強度、耐疲
労、耐全面腐食、耐孔食、耐隙間腐食、耐応力腐
食割れ、耐水素脆性用アモルフアス鉄合金、なら
びに特願昭53−10397（特開昭54−103730）によ
り、炭素系非晶質鉄合金を発明して特許出願した
が、これらのアモルフアス鉄合金は1N塩酸、1N
硫酸又は1N食塩水溶液中でも高度の耐食性を示
し、全面腐食および孔食が全く起こらないことを
開示した。
前記特開昭51−4017により開示したアモルフア
ス鉄合金は、原子％として、Cr1〜40％とＰ、Ｃ
及びＢのうち何れか１種または２種以上７〜35％
を主成分として含み、かつ副成分として、
(1) Ni及びCoの何れか１種または２種0.01〜40
％。
(2) Mo、Zr、Ti、Si、Al、Pt、Mn及びPdの何
れか１種または２種以上0.01〜20％。
(3) Ｖ、Nb、Ta、Ｗ、Ge、及びBeの何れか１種
または２種以上0.01〜10％。
(4) Au、Cu、Zn、Cd、Sn、As、Sb、Bi及びＳ
の何れか１種または２種以上0.01〜５％。
の群のうちから選ばれた何れか１群または２群以
上を合計量で0.01〜75％を含有し、残部は実質的
にFeの組成からなるものである。
また、前記特開昭54−103730により開示した炭
素系非晶質鉄合金は、
Fe ａ Cr ｂ Ｍ ｃ Ｑ ｄ
（式中FeaはFeがａ原子％、CrbはCrがｂ原子
％、McはCr、Mo、Ｗのうちからえらばれる何れ
か１種または２種以上がｃ原子％、QdはＣがｄ
原子％含有されていることを示す。）
の式で示される成分組成よりなるものであつて、
そのうち耐食性に優れたるものは、ａが28〜28、
ｂが２〜20、ｃが４〜26、ｄが12〜26の範囲内に
ある炭素系非晶質鉄合金であることを開示した。
上記発明からわかるように、アモルフアス鉄合
金においては、結晶質の合金と同様に、耐食性を
向上させるためにもつとも効率的な合金添加物は
クロムであり、クロムのほかにモリブデンの添加
がクロムを含む鉄基アモルフアス合金の耐食性を
改善する。
ところで、本発明者らは前記２つの発明合金に
ついて、さらに耐食性を調べた結果、1N塩酸水
溶液より高濃度の塩酸水溶液に対して、成分組成
範囲の違いにより極めて強い耐食性を示す成分組
成範囲と、比較的弱い耐食性を示す成分組成範囲
があることを見出し、さらにまた前記1N塩酸水
溶液以上の場合に見られる強腐食環境にあつて
は、前記発明合金では十分な耐食性を発揮するこ
とができないことを知つた。その一例として3N
塩酸水溶液（室温）、6N硝酸水溶液（室温）及び
18N硫酸水溶液（80℃）などで腐食速度を実験し
た結果を第１表に示す。
The present invention relates to an ultra-high corrosion-resistant amorphous amorphous alloy, and in particular, the present invention relates to an ultra-high corrosion-resistant Fe-Cr-Mo amorphous alloy that has corrosion resistance in a corrosive environment of about 6NHCl or higher. Traditionally, common corrosion-resistant alloys that have been widely used include stainless steel alloys, such as 13% chromium steel, 18-8 stainless steel (304 steel), 17-14-2.5Mo stainless steel (316 steel), and nickel-based alloys. can be,
Excellent weather resistance and corrosion resistance. However, in even more corrosive environments, such as 1N aqueous hydrochloric acid, the passive film is destroyed and almost all conventional corrosion-resistant alloys suffer from pitting corrosion. On the other hand, one of the inventors previously filed a patent application for
74246 (Japanese Unexamined Patent Publication No. 51-4017), an amorphous iron alloy with high strength, fatigue resistance, general corrosion resistance, pitting corrosion resistance, crevice corrosion resistance, stress corrosion cracking resistance, and hydrogen embrittlement resistance, and patent application No. 53-10397 ( (Japanese Patent Application Laid-open No. 54-103730) invented carbon-based amorphous iron alloys and applied for a patent, but these amorphous iron alloys were treated with 1N hydrochloric acid,
It was disclosed that it shows a high degree of corrosion resistance even in sulfuric acid or 1N saline solution, and that no general corrosion or pitting corrosion occurs. The amorphous iron alloy disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 51-4017 contains 1 to 40% Cr, P, and C in terms of atomic percent.
and 7 to 35% of one or two or more of B
as a main component, and as a subcomponent: (1) Any one or both of Ni and Co 0.01 to 40
%. (2) 0.01 to 20% of one or more of Mo, Zr, Ti, Si, Al, Pt, Mn, and Pd. (3) 0.01 to 10% of one or more of V, Nb, Ta, W, Ge, and Be. (4) Au, Cu, Zn, Cd, Sn, As, Sb, Bi and S
0.01 to 5% of one or more of the following. The total amount of one or more selected from the group of 0.01 to 75% is contained, and the remainder is substantially composed of Fe. Further, the carbon-based amorphous iron alloy disclosed in JP-A-54-103730 is Fe a Cr b M c Q d (where Fea is a atomic % of Fe, Crb is Cr is b atomic %, and Mc is Any one or more selected from Cr, Mo, and W is c atomic %, and Qd is C d
Indicates that the content is atomic%. ), which has a component composition shown by the formula:
Among them, those with excellent corrosion resistance have a of 28 to 28,
It was disclosed that it is a carbon-based amorphous iron alloy in which b is in the range of 2 to 20, c is in the range of 4 to 26, and d is in the range of 12 to 26. As can be seen from the above invention, in amorphous iron alloys, as in crystalline alloys, chromium is the most effective alloy additive for improving corrosion resistance, and addition of molybdenum in addition to chromium includes chromium. Improves the corrosion resistance of iron-based amorphous alloys. By the way, the present inventors further investigated the corrosion resistance of the above-mentioned two invention alloys, and found that due to the difference in the component composition range, a component composition range showing extremely strong corrosion resistance against a hydrochloric acid aqueous solution with a higher concentration than a 1N hydrochloric acid aqueous solution, It has been discovered that there is a composition range that exhibits relatively weak corrosion resistance, and furthermore, it has been found that the invention alloy cannot exhibit sufficient corrosion resistance in the strongly corrosive environment found in the above-mentioned 1N aqueous hydrochloric acid solution or higher. I knew. As an example, 3N
Hydrochloric acid aqueous solution (room temperature), 6N nitric acid aqueous solution (room temperature) and
Table 1 shows the results of experiments on corrosion rates using 18N sulfuric acid aqueous solution (80℃).
【表】【table】
【表】
よつて本発明者らはきびしい腐食環境として、
6N塩酸水溶液を選定し、前記発明合金の耐食性
について改めて種々検討を重ね、ようやく本発明
のアモルフアス合金の成分組成範囲がもつとも優
れた耐食性を有することを新規に知見して本発明
を完成した。
本発明はこのような理由からなされたもので、
その目的とするところは6N塩酸あるいは熱塩酸
のような強腐食性環境下で耐食性を維持すること
のできる超高耐食性Fe−Cr−Mo系アモルフアス
合金を提供することにある。
すなわち、本発明はFe、Cr及びMoと半金属か
らなるアモルフアス合金において、Cr5原子％以
上、Mo20原子％以下で、CrとMoの合計が15〜35
原子％の範囲内にあり、半金属元素はＰ−Si系か
らなり、P10原子％以上、Si5原子％以上で、そ
の合計が20〜25原子％の範囲内にある超高耐食性
Fe−Cr−Mo系アモルフアス合金である。
以下本発明を詳細に説明する。
まず本発明に係る合金の成分元素の添加理由お
よび添加範囲の限定理由について説明する。
アモルフアス合金は通常同組成の結晶質合金よ
り高活性のため腐食を受けやすいものであること
が一般に知られているが、クロムを含む鉄基アモ
ルフアス合金は同一成分組成の結晶質合金ならび
に従来の耐食性合金よりも高度な耐食性を示すこ
とが知られている。本発明者らは前記クロムを含
む鉄基アモルフアス合金が耐食性を有する原因に
ついて考究し、その原因はアモルフアス合金自体
の化学的均一性と高活性によるものであり、前記
化学的均一性は均一な不動態膜を形成するために
役立ち、前記高活性は前記不動態膜を急速に生成
し、かつ強固緻密にするのに役立つていることを
知見した。前記不動態膜は主としてクロム水酸化
物の水和物からなり、その不動態膜中のクロム水
酸化物の富化が不動態膜の高度な保護特性のため
の大切な要因である。モリブデンは前記不動態膜
の富化に大きな効果をもつている。したがつて、
クロムの添加は耐食性にとつて不可欠のものであ
り、またモリブデンの添加は不動態膜の生成を助
長するものである。
そこで合金系としてFe−Cr−Mo系を選定し、
室温、あるいは80℃の6N塩酸水溶液などの種々
の強腐食環境の中で、ポテンシオスタツト法（動
電位法）により分極曲線を測定して自己不動態化
する成分組成範囲を調べた。
つぎに上記自己不動態化する成分組成範囲を研
究データについて説明する。
第１図に示すようにFe−Cr−Mo−15P−5Siア
モルフアス合金において、室温6N塩酸では、Cr5
原子％あるいはそれ以上含むものはMo10原子％
以上で自己不動態化し、Cr10原子％あるいはそ
れ以上含むものはMo5原子％の添加で十分自己不
動態化する。第１図において、それぞれの点を結
ぶ一連の線の上下に施した斜線領域は6NHClに対
する自己不動態化領域であり、上記それぞれの一
連の線の下方は活性領域である。したがつて、
Crの含有量を５原子％以上とし、CrとMoの合計
を15原子％以上とする必要がある。Cr含有量を
増加すると、自己不動態化するために必要なMo
添加量は減少し、たとえばFe−25Cr−2Mo−15P
−5Si合金−6N塩酸水溶液中で自己不動態化する
ことが同図よりわかる。また大量のMoの添加は
腐食電位を上昇させる効果はあるが、第２図から
判るように一定量のMo以上では腐食速度が一定
となり、特に効果が見出されない。したがつて
Mo添加量を20原子％以上とするのはとくにMoが
高価な元素であることもあり得策ではない。な
お、Moが20原子％以上あるいはCrとMoの合計が
35原子％以上になるとアモルフアス形成能が悪く
なる。つぎにさらにきびしい腐食条件では、第１
図から判るように6N塩酸水溶液（80℃）中での
分極曲線測定の結果、15P−5Si系合金ではCr5原
子％でMo15原子％あるいはそれ以上のとき、ま
たはCr10原子％でMo10原子％あるいはそれ以上
のとき自己不動態化するが、Crが10原子％以上
に増加しても自己不動態化に必要なMo量は減少
しないことが判明した。
つぎに半金属の選定理由およびその濃度範囲に
ついて説明する。
アモルフアス合金を製造するために半金属元素
の添加が必要であり、一般にＰ、Ｃ、Ｂ、Siが使
用され、これら元素の添加によりおのおの製造さ
れるアモルフアス鉄合金の性質にそれぞれ異なつ
た特徴が見られる。その効果は特開昭54−103730
に原料費、溶解性、非晶質形成能、結晶化温度、
硬さ、強さ、耐食性、脆化について詳細に示した
が、その結果からＰ−Ｃ系、Ｐ−Ｂ系、Ｐ−Si
系、Si−Ｂ系、Ｃ系について実験した結果、その
一部を第１表に示したようにＢならびにＢとＢ以
外の半金属を含むものは耐食性がおとり、そのう
え原料費が高いこともあり、半金属系としてＰ−
Ｃ系、Ｐ−Si系、Ｃ系を選定した。
これらの半金属元素の添加量については第３図
に示すように、Fe−10Cr−5Mo−Ｐ−Si系にお
いてＰとSiの合計が20原子％以上のとき室温、
6N塩酸水溶液中で自己不動態化する。さらにＰ
とSi系の合計を増加することによつてCrとMoが
節約できる。たとえば第１図に示したようにＰと
Siの合計が25原子％（P15原子％、Si10原子％）
ではCrとMoの合計が10原子％以上で室温6N塩酸
水溶液中で自己不動態化するようになる。このこ
とはMoが高価であるため、実用合金として考え
た場合経済的に非常に大切なことであるが、Ｐと
Siの合計が25原子％を超えると、合金のアモルフ
アス形成能が悪くなるのでＰとSiの合計は25原子
％以下にする必要がある。また、半金属元素とし
てＰ又はSi単独では目的とする高耐食性が得られ
ず、ＰをSiを共存させることが必要であり、第３
図から分かるようにＰは10原子％以上、Siは５原
子％以上とする必要がある。
特開昭54−103730においてSiの添加はＢより耐
食性をそこなうものと記載されているが、Ｐと組
合わせることによつて耐食性を示すようになるこ
とを本発明者らは新規に知見した。
Crの含有量が25原子％以上になると、Fe−Cr
−Mo系アモルフアス合金の場合、Ｐ−Si系より
もＣ系の方がアモルフアス合金の製造が容易にな
る。またＰ−Si系よりＣ系の方が安価な原料を使
用できることもあり、Fe−（25〜35）Cr−Mo−
18C系について、その耐食性を80℃、6N塩酸水溶
液中で測定した。その結果第１図に示したように
Moを10原子％あるいはそれ以上含むものが自己
不動態化することが判つた。しかし同じ量のCr
とMoを含むＰ−Si系と比較すると腐食電位が低
く、陽極電流密度が高いため耐食性において劣
る。
本発明に係るFe−Cr−Mo系アモルフアス合金
の製造方法は通常行なわれる液体金属の超急冷法
によるものである。すなわち配合素材は、鉄源と
して銑鉄あるいは純鉄、合金元素であるクロムま
たはモリブデンは市販純金属あるいはフエロクロ
ムまたはフエロモリブデン、半金属源として市販
純物質あるいはフエロボロン、フエロホスホル、
フエロシリコン、セメンタイトを使用し、配合後
加熱溶解し、冷却体の移動冷却面上にノズルから
前記溶解合金溶湯を射出、急冷凝固させて本発明
合金を製造することができる。
本発明合金において、合金元素源としてフエロ
アロイを使用できることはその経済性、生産性に
おいて極めて大きな利点である。すなわち、クロ
ムまたはモリブデン源としてフエロクロム、また
はフエロモリブデンは今日もつとも安価な原料で
あること、またフエロクロムはすでにFe−Cr−
Ｃ系合金であり、融点が低いこと、フエロモリブ
デンも純モリブデンに比較して著るしく低融点で
あり、均一な溶融合金を大量に製造するために好
適である。さらにこれらのフエロアロイ中の不純
物は主として、Ｐ、Siであることから、本発明合
金を製造するにはむしろ好影響を及ぼす元素であ
る。
つぎに本発明を実施例について説明する。
実施例 １
Cr10原子％、Mo0、２、５、７、10、原子
％、P15原子％、Si5原子％、残部Feよりなるア
モルフアス合金を片ロール法（ロール直径30cm
φ、回転数2000〜3000rpm）によつて製造し、こ
のアモルフアス合金を室温6NHCl中で浸漬して腐
食速度を調べた。上記Fe−10Cr−Mo−15P−5Si
アモルフアス合金は分極曲線測定結果よりMo5原
子％以上で自己不動態化し、腐食速度は、第２図
に示したようにMo5原子％以上で著しく小さくな
り、耐食性が極めて優秀であつた。
実施例 ２
Cr25原子％、Mo10原子％、P15原子％、Si10
原子％、残部Feよりなるアモルフアス合金を実
施例１と同一方法により製造した。それを室温で
6NHClと6NHNO3及び80℃で6NHClと18NH2SO4
中に浸漬して腐食速度を測定した。その結果、腐
食速度は非常に小さく優れた耐食性を示した。第
２図は80℃で6NHClにおける腐食速度をMo原子
％に対してプロツトした図であり、上記合金より
Moの多い合金は腐食速度が著しく減少した。
比較例として、18−８ステンレス鋼、純チタ
ン、および純タンタルを用いて80℃で6NHClへの
浸漬試験を行つた結果を第２図に示したが、室温
あるいは高温たとえば80℃の6NHClのような高腐
食性環境下で、本発明によるFe−Cr−Mo系アモ
ルフアス合金は純タンタルに若干劣るが、18−８
ステンレス鋼およびチタンなどにより数段優れた
耐食合金であることが判つた。
以上、本発明のアモルフアス合金は細い条、薄
板として製造可能であり、従来の実用材料では得
られない耐食性を有し、かつ従来の実用材料に比
し、極めて安価な材料である。また本発明の組成
のアモルフアス合金はすでに開示した如く、破壊
強度380Kg／mm2、硬さHV950程度と高強度、高硬
度である。したがつて本発明のアモルフアス合金
は化学プラント、原子炉、耐海水性機器などの強
度ならびに高耐食性が必要とされる構造用材なら
びに部品材料として従来の耐食性材料に比し、優
れた特徴を有する。[Table] Therefore, the present inventors have determined that the severe corrosive environment
After selecting a 6N hydrochloric acid aqueous solution and conducting various studies on the corrosion resistance of the invention alloy, we finally discovered that the amorphous alloy of the invention has excellent corrosion resistance within the composition range, and completed the invention. The present invention was made for these reasons.
The purpose is to provide an ultra-high corrosion-resistant Fe-Cr-Mo amorphous alloy that can maintain corrosion resistance in strongly corrosive environments such as 6N hydrochloric acid or hot hydrochloric acid. That is, the present invention provides an amorphous amorphous alloy consisting of Fe, Cr, Mo, and a semimetal, in which Cr is 5 atomic % or more and Mo 20 atomic % or less, and the total of Cr and Mo is 15 to 35 atomic %.
ultra-high corrosion resistance within the range of atomic%, the metalloid element is composed of P-Si system, P10 atomic% or more, Si 5 atomic% or more, and the total is within the range of 20 to 25 atomic%
It is a Fe-Cr-Mo based amorphous alloy. The present invention will be explained in detail below. First, the reason for adding the constituent elements of the alloy according to the present invention and the reason for limiting the range of addition will be explained. It is generally known that amorphous amorphous alloys are more susceptible to corrosion due to their higher activity than crystalline alloys of the same composition, but iron-based amorphous alloys containing chromium have higher corrosion resistance than crystalline alloys of the same composition and conventional It is known to exhibit higher corrosion resistance than alloys. The present inventors investigated the cause of the corrosion resistance of the iron-based amorphous amorphous alloy containing chromium, and found that the cause is the chemical uniformity and high activity of the amorphous amorphous alloy itself, and the chemical uniformity is due to uniform unevenness. It was found that the high activity helps to form a dynamic film, and the high activity helps to form the passive film rapidly and make it strong and dense. The passive film mainly consists of hydrated chromium hydroxide, and the enrichment of chromium hydroxide in the passive film is an important factor for the high protective properties of the passive film. Molybdenum has a great effect on enriching the passive film. Therefore,
The addition of chromium is essential for corrosion resistance, and the addition of molybdenum promotes the formation of a passive film. Therefore, we selected the Fe-Cr-Mo alloy system,
We investigated the composition range of components that self-passivate by measuring polarization curves using the potentiostat method in various strongly corrosive environments such as room temperature or 6N hydrochloric acid aqueous solution at 80°C. Next, the composition range of the above self-passivating components will be explained using research data. As shown in Figure 1, in the Fe-Cr-Mo-15P-5Si amorphous alloy, Cr5
Those containing atomic% or more are Mo10 atomic%.
The above results in self-passivation, and for those containing 10 atomic % or more of Cr, addition of 5 atomic % of Mo is sufficient to self-passivate. In FIG. 1, the shaded areas above and below the series of lines connecting each point are the self-passivation regions for 6NHCl, and below each of the series of lines is the active region. Therefore,
The content of Cr must be 5 atomic % or more, and the total of Cr and Mo must be 15 atomic % or more. Increasing the Cr content reduces the amount of Mo required to self-passivate.
The amount added decreases, for example Fe−25Cr−2Mo−15P
The figure shows that -5Si alloy self-passivates in 6N hydrochloric acid aqueous solution. Furthermore, although the addition of a large amount of Mo has the effect of increasing the corrosion potential, as can be seen from FIG. 2, above a certain amount of Mo, the corrosion rate becomes constant and no particular effect is found. Therefore
It is not a good idea to add Mo in an amount of 20 atomic % or more, especially since Mo is an expensive element. In addition, Mo is 20 atomic% or more or the total of Cr and Mo is
When the content exceeds 35 atomic %, the amorphous amorphous formation ability deteriorates. Next, under even more severe corrosion conditions, the first
As can be seen from the figure, as a result of polarization curve measurement in 6N hydrochloric acid aqueous solution (80℃), in 15P-5Si alloy, when Cr5 at% and Mo15 at% or more, or Cr10 at% and Mo10 at% or more, Self-passivation occurs in the above cases, but it was found that the amount of Mo required for self-passivation does not decrease even if Cr increases to 10 atomic % or more. Next, the reason for selecting the metalloid and its concentration range will be explained. In order to manufacture amorphous iron alloys, it is necessary to add metalloid elements, and generally P, C, B, and Si are used, and the properties of the amorphous iron alloys produced by the addition of these elements have different characteristics. It will be done. The effect is JP-A-54-103730
raw material cost, solubility, ability to form amorphous, crystallization temperature,
Hardness, strength, corrosion resistance, and embrittlement were shown in detail, and the results showed that P-C system, P-B system, P-Si
As a result of experiments on B, Si-B, and C systems, some of which are shown in Table 1, those containing B and metalloids other than B and B have poor corrosion resistance, and also have high raw material costs. Yes, P- as a metalloid
C system, P-Si system, and C system were selected. Regarding the amount of these metalloid elements added, as shown in Figure 3, when the total of P and Si is 20 atomic % or more in the Fe-10Cr-5Mo-P-Si system, at room temperature,
Self-passivate in 6N aqueous hydrochloric acid. Further P
Cr and Mo can be saved by increasing the sum of Si and Si. For example, as shown in Figure 1, P and
Total Si content is 25 atomic% (P15 atomic%, Si 10 atomic%)
When the total content of Cr and Mo exceeds 10 atomic %, self-passivation occurs in room temperature 6N hydrochloric acid aqueous solution. This is economically very important when considering it as a practical alloy because Mo is expensive, but
If the total amount of Si exceeds 25 atomic percent, the amorphous amorphous forming ability of the alloy deteriorates, so the total amount of P and Si must be 25 atomic percent or less. In addition, the desired high corrosion resistance cannot be obtained by using P or Si alone as semimetallic elements, and it is necessary to coexist P with Si.
As can be seen from the figure, P needs to be at least 10 atomic % and Si needs to be at 5 atomic % or more. Although it is stated in JP-A-54-103730 that the addition of Si impairs corrosion resistance more than B, the present inventors have newly discovered that when combined with P, corrosion resistance is exhibited. When the Cr content is 25 at% or more, Fe-Cr
In the case of -Mo-based amorphous alloys, C-based amorphous alloys are easier to manufacture than P-Si-based. In addition, C-based materials can use cheaper raw materials than P-Si-based materials, and Fe-(25-35)Cr-Mo-
The corrosion resistance of 18C series was measured in 6N hydrochloric acid aqueous solution at 80°C. The result is as shown in Figure 1.
It was found that materials containing 10 atomic % or more of Mo self-passivate. But the same amount of Cr
Compared to the P-Si system containing Mo, the corrosion potential is lower and the anode current density is higher, resulting in inferior corrosion resistance. The method for producing the Fe-Cr-Mo amorphous alloy according to the present invention is based on a commonly used ultra-quenching method of liquid metal. In other words, the compounded materials include pig iron or pure iron as the iron source, chromium or molybdenum as the alloying element, commercially available pure metals or ferrochrome or ferromolybdenum, and commercially available pure substances as the semimetal source, ferroboron, ferrophosphor,
The alloy of the present invention can be produced by using ferrosilicon or cementite, heating and melting after blending, injecting the molten alloy from a nozzle onto the moving cooling surface of a cooling body, and rapidly solidifying it. In the alloy of the present invention, the ability to use ferroalloy as an alloying element source is extremely advantageous in terms of economy and productivity. In other words, as a source of chromium or molybdenum, ferrochrome or ferromolybdenum is a cheap raw material today, and ferrochrome has already been used as a Fe-Cr-
It is a C-based alloy and has a low melting point, and ferromolybdenum also has a significantly lower melting point than pure molybdenum, making it suitable for producing a uniform molten alloy in large quantities. Furthermore, since the impurities in these ferroalloys are mainly P and Si, they are elements that have a rather favorable effect on the production of the alloy of the present invention. Next, the present invention will be explained with reference to examples. Example 1 An amorphous amorphous alloy consisting of 10 atomic% Cr, 2, 5, 7, 10 atomic% Mo, 15 atomic% P, 5 atomic% Si, and the balance Fe was processed using a single roll method (roll diameter 30 cm).
This amorphous alloy was immersed in 6NHCl at room temperature to examine its corrosion rate. Above Fe−10Cr−Mo−15P−5Si
The polarization curve measurement results show that the amorphous alloy self-passivates when Mo is 5 atomic % or more, and the corrosion rate is significantly reduced when Mo is 5 atomic % or more, as shown in Figure 2, indicating that it has extremely excellent corrosion resistance. Example 2 Cr25 atomic%, Mo10 atomic%, P15 atomic%, Si10
An amorphous amorphous alloy consisting of atomic percent and balance Fe was manufactured by the same method as in Example 1. it at room temperature
6NHCl and 6NHNO 3 and 6NHCl and 18NH 2 SO 4 at 80 °C
The corrosion rate was measured by immersing it in the water. As a result, the corrosion rate was extremely low and excellent corrosion resistance was demonstrated. Figure 2 is a diagram plotting the corrosion rate in 6NHCl at 80°C against Mo atomic %.
The corrosion rate of Mo-rich alloys was significantly reduced. As a comparative example, Figure 2 shows the results of an immersion test in 6NHCl at 80°C using 18-8 stainless steel, pure titanium, and pure tantalum. In a highly corrosive environment, the Fe-Cr-Mo amorphous alloy according to the present invention is slightly inferior to pure tantalum, but has a 18-8
It was found that this alloy is far superior in corrosion resistance to stainless steel, titanium, etc. As described above, the amorphous alloy of the present invention can be manufactured as a thin strip or thin plate, has corrosion resistance that cannot be obtained with conventional practical materials, and is extremely inexpensive compared to conventional practical materials. Further, as already disclosed, the amorphous amorphous alloy having the composition of the present invention has high strength and hardness, with a breaking strength of 380 Kg/mm 2 and a hardness of about HV950. Therefore, the amorphous amorphous alloy of the present invention has superior characteristics compared to conventional corrosion-resistant materials as a structural material and component material that require strength and high corrosion resistance for chemical plants, nuclear reactors, seawater-resistant equipment, etc.
第１図は不動態膜生成に及ぼすCrとMoの量の
影響を示す図、第２図はCr、Mo含有量と腐食速
度の関係を示す図、第３図は不動態膜生成に及ぼ
すＰとＣ、ならびにＰとSiの影響を示す図であ
る。
Figure 1 shows the influence of the amounts of Cr and Mo on the formation of a passive film, Figure 2 shows the relationship between the Cr and Mo contents and the corrosion rate, and Figure 3 shows the effect of P on the formation of a passive film. and C, as well as the influence of P and Si.
Claims (1)
アス合金において、Cr5原子％以上、Mo20原子
％以下で、CrとMoの合計が15〜35原子％の範囲
内にあり、半金属元素はＰ−Si系からなり、P10
原子％以上、Si5原子％以上でその合計が20〜25
原子％の範囲内にあることを特徴とする超高耐食
性Fe−Cr−Mo系アモルフアス合金。 ２ Cr5原子％以上、Mo10〜20原子％の範囲内
で、CrとMoの合計が20〜35原子％の範囲内にあ
る特許請求の範囲第１項に記載の超高耐食性Fe
−Cr−Mo系アモルフアス合金。[Claims] 1. In an amorphous alloy consisting of Fe, Cr and Mo and a metalloid, Cr is 5 atomic % or more and Mo 20 atomic % or less, and the total of Cr and Mo is in the range of 15 to 35 atomic %, The metal element consists of P-Si system, P10
atomic% or more, Si5 atomic% or more, and the total is 20 to 25
An ultra-high corrosion resistant Fe-Cr-Mo amorphous alloy characterized by a corrosion resistance within the range of atomic %. 2. The ultra-high corrosion-resistant Fe according to claim 1, in which the content of Cr is 5 atomic % or more, the Mo content is within the range of 10 to 20 atomic %, and the total of Cr and Mo is within the range of 20 to 35 atomic %.
-Cr-Mo based amorphous alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11092786A JPS6244557A (en) | 1986-05-16 | 1986-05-16 | Amorphous fe-cr-mo alloy having extremely high corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11092786A JPS6244557A (en) | 1986-05-16 | 1986-05-16 | Amorphous fe-cr-mo alloy having extremely high corrosion resistance |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56209989A Division JPS58113354A (en) | 1981-12-28 | 1981-12-28 | Amorphous fe-cr-mo alloy with superhigh corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6244557A JPS6244557A (en) | 1987-02-26 |
| JPS6240417B2 true JPS6240417B2 (en) | 1987-08-28 |
Family
ID=14548138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11092786A Granted JPS6244557A (en) | 1986-05-16 | 1986-05-16 | Amorphous fe-cr-mo alloy having extremely high corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6244557A (en) |
-
1986
- 1986-05-16 JP JP11092786A patent/JPS6244557A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6244557A (en) | 1987-02-26 |
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