JPH04183837A - Austenite system ni-cr-mn-fe alloy - Google Patents
Austenite system ni-cr-mn-fe alloyInfo
- Publication number
- JPH04183837A JPH04183837A JP30868590A JP30868590A JPH04183837A JP H04183837 A JPH04183837 A JP H04183837A JP 30868590 A JP30868590 A JP 30868590A JP 30868590 A JP30868590 A JP 30868590A JP H04183837 A JPH04183837 A JP H04183837A
- Authority
- JP
- Japan
- Prior art keywords
- equivalent
- content
- hydrogen embrittlement
- grain boundaries
- alloy
- 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
- 229910000640 Fe alloy Inorganic materials 0.000 title claims abstract description 6
- 229910001566 austenite Inorganic materials 0.000 title abstract description 6
- 239000000956 alloy Substances 0.000 claims abstract description 10
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 7
- 239000000463 material Substances 0.000 abstract description 28
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 27
- 239000001257 hydrogen Substances 0.000 abstract description 27
- 230000007812 deficiency Effects 0.000 abstract description 15
- 238000005260 corrosion Methods 0.000 abstract description 12
- 229910052804 chromium Inorganic materials 0.000 abstract description 11
- 229910052759 nickel Inorganic materials 0.000 abstract description 7
- 229910052799 carbon Inorganic materials 0.000 abstract description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract 1
- 239000011651 chromium Substances 0.000 description 51
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 27
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 25
- 230000007797 corrosion Effects 0.000 description 11
- 206010070834 Sensitisation Diseases 0.000 description 10
- 238000010586 diagram Methods 0.000 description 10
- 230000008313 sensitization Effects 0.000 description 10
- 230000007423 decrease Effects 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000002950 deficient Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910000990 Ni alloy Inorganic materials 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910000856 hastalloy Inorganic materials 0.000 description 2
- 229910001026 inconel Inorganic materials 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- -1 Illium Inorganic materials 0.000 description 1
- 229910000792 Monel Inorganic materials 0.000 description 1
- 229910018487 Ni—Cr Inorganic materials 0.000 description 1
- UFGZSIPAQKLCGR-UHFFFAOYSA-N chromium carbide Chemical compound [Cr]#C[Cr]C#[Cr] UFGZSIPAQKLCGR-UHFFFAOYSA-N 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910001293 incoloy Inorganic materials 0.000 description 1
- 229910001055 inconels 600 Inorganic materials 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910001235 nimonic Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000001603 reducing effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910003470 tongbaite Inorganic materials 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は、加工性がよく、Ｎｉ、Ｃｒ資源の節約型の耐
水素脆性、耐食性材料に係り、特に高温ガス工業など水
素を含む還元性ガスを取扱うプラント用材料および原子
炉内で中性子照射を受ける原子炉用材料に好適な材料の
提供に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to hydrogen embrittlement and corrosion resistant materials that have good workability and save Ni and Cr resources, particularly for reducing properties containing hydrogen such as in the high temperature gas industry. The present invention relates to the provision of materials suitable for plants that handle gas and materials for nuclear reactors that receive neutron irradiation in nuclear reactors.
［従来の技術］
まず、従来の公知例としては、特開昭６２−１５８８４
４号公報があるが、これは添加するＭｎ量は２％以下に
規制されているほか、耐中性子照射効果については記載
されていない。[Prior Art] First, as a conventionally known example, Japanese Patent Laid-Open No. 62-15884
Although there is a publication No. 4, the amount of Mn added is regulated to 2% or less, and the neutron irradiation resistance effect is not described.
従来の高Ｎｉ合金には、インコネル、インコロイ、モネ
ル、ハステロイ、イリウム、ニモニック等がある。これ
らについての詳細は、（１）日刊工業新聞社：高ニッケ
ル合金、工業材料便覧、ｐ５１８及び（２） １１Ｈｕ
ｎｔｉｎｇｔｏｎ Ａ１１ｏｙｓ Ｈａｎｄ Ｂｏｏｋ
。Conventional high Ni alloys include Inconel, Incoloy, Monel, Hastelloy, Illium, Nimonic, and the like. For details on these, see (1) Nikkan Kogyo Shimbun: High Nickel Alloys, Industrial Materials Handbook, p518 and (2) 11Hu
ntington A11oys Hand Book
.
Ｎｏｍ１ｎａｌ Ｃｈｅｍｉｃａｌ Ｃｏｍｐｏｓｉｔ
ｉｏｎ、１９７０”に記載されている。Noml Chemical Composite
ion, 1970''.
たとえば、インコネルは、通常Ｎｉ含有量は６０％以上
であるが、水素脆化率が高いためよくない。また、ハス
テロイ−又は、水素脆化率は、低く良好であるが、Ｃｒ
含有量は２２％以下であり、使用中には、鋭敏化のため
にＣｒ量が約１ｏ％減少して、選択的に腐食される傾向
がある。For example, Inconel usually has a Ni content of 60% or more, which is not good because it has a high hydrogen embrittlement rate. In addition, the Hastelloy or hydrogen embrittlement rate is low and good, but Cr
The content is 22% or less, and during use, the amount of Cr decreases by about 10% due to sensitization and tends to be selectively corroded.
通常使用されている５ＵＳ３０４．３１６などは、水素
脆化率が高いために好ましくない。Commonly used materials such as 5US304.316 are not preferred because of their high hydrogen embrittlement rate.
以上のように、最適な材料は得られていない。As mentioned above, the optimal material has not been obtained.
［発明が解決しようとする課題］
原子力発電所の長寿命化に関して、原子炉内で使用され
る炉内構造材料の材質の改善が期待されている。その−
環として、加工性がすぐれ、耐水素脆性および耐食性が
良好な材料を提案する。[Problems to be Solved by the Invention] In order to extend the life of nuclear power plants, it is expected to improve the quality of the internal structural materials used in nuclear reactors. That-
For the ring, we propose a material with excellent workability, hydrogen embrittlement resistance, and corrosion resistance.
鋼の耐水素脆性については、第４図および第５図に示す
ように鋼中のＮｉ当量［Ｎ１ｅｑ＝Ｎｉ＋３０ＸＣ＋３
０ＸＮ＋０．５ＸＭｎ （％）］あるいはＮｉ含有量依
存性があり、Ｎｉ当量が多い程、水素脆化率は低下する
が、Ｎｉ当量が多くなり過ぎると再び感受性が上昇する
。また、Ｎｉは貴重かつ高価な成分元素である。Regarding the hydrogen embrittlement resistance of steel, as shown in Figures 4 and 5, the Ni equivalent in steel [N1eq=Ni+30XC+3
0XN+0.5XMn (%)] or depending on the Ni content; the higher the Ni equivalent, the lower the hydrogen embrittlement rate, but if the Ni equivalent becomes too large, the susceptibility increases again. Further, Ni is a valuable and expensive component element.
一方、鋼の耐食性を向上させる方法として、Ｃｒの不働
態皮膜生成による方法があり、Ｃｒが添加されるが、第
６図および第７図に示すように、ステンレス鋼に対する
鋭敏化および中性子照射により、結晶粒界のＣｒ量が欠
乏するために耐食性が低下することが知られている。第
６図は、鋭敏化（６００℃×５７Ｈｒ）による粒界のＣ
ｒ欠乏図、第７図は、中性子照射による粒界のＣｒ欠乏
図である。On the other hand, as a method to improve the corrosion resistance of steel, there is a method of forming a passive film of Cr, in which Cr is added. It is known that corrosion resistance decreases due to a lack of Cr in grain boundaries. Figure 6 shows the C of grain boundaries due to sensitization (600°C x 57 hours).
FIG. 7 is a Cr deficiency diagram of grain boundaries due to neutron irradiation.
すなわち、第６図は、ステンレス鋼を、６００℃、５７
時間の加熱後の粒界近傍におけるＣｒ濃度の減少状況を
示す試験結果を示すものである。That is, Fig. 6 shows stainless steel heated at 600°C and 57°C.
This figure shows test results showing how the Cr concentration decreases in the vicinity of grain boundaries after heating for hours.
これによると粒界では、Ｃｒは約８％欠乏していること
がわかる。また、第７図は、ステンレス鋼（ＳＵＳ−３
０４）を、３００℃で中性子照射（照射量： １０””
１０２２ｎ ／ａ＃） した場合のＣｒの粒界／マト
リックスのＸ線強度化をプロットしたものである。Ｘ線
強度化が１．０は、粒界とマトリックスのＣｒ量が等し
いことを示すもので、例えば中性子照射量１０”ｎ／ａ
＃の場′合には、粒界のＣｒ量はマトリックスに対して
１０％以上欠乏したことがわかる。This shows that Cr is deficient by about 8% at the grain boundaries. In addition, Fig. 7 shows stainless steel (SUS-3
04) was irradiated with neutrons at 300°C (irradiation dose: 10”)
1022n/a#) is a plot of the X-ray intensity enhancement of Cr grain boundaries/matrix. An X-ray intensity of 1.0 indicates that the amount of Cr in the grain boundary and matrix is equal; for example, when the neutron irradiation amount is 10"n/a
In the case of #', it can be seen that the amount of Cr at the grain boundaries was depleted by 10% or more with respect to the matrix.
以上のことを考慮して、上記従来の材料を評価すると、
Ｎｉ含有量に関しては、耐水素脆性が不良な範囲に属す
る材料が大部分を占めている。−部にＮｉ含有量が適切
な材料はあるが、これについては、Ｃｒ量の減少による
耐食性の低下に対する配慮がなされていないので、Ｃｒ
欠乏に基づく耐食性の劣化という点で好適な材料とは云
えない。Considering the above, when evaluating the above conventional materials,
Regarding the Ni content, most of the materials have poor hydrogen embrittlement resistance. Although there are materials with appropriate Ni content in the - part, no consideration has been given to the decrease in corrosion resistance due to a decrease in the amount of Cr.
It cannot be said to be a suitable material in terms of deterioration of corrosion resistance due to deficiency.
本発明の目的は、Ｎｉ節約型であり、耐水素脆性が良好
で、かつＣｒ節約型であり材料の加工性を良好に保つこ
とができるような材料を提供することである。An object of the present invention is to provide a material that is Ni-saving, has good hydrogen embrittlement resistance, and Cr-saving, and can maintain good workability.
［課題を解決するための手段］
上記課題を解決するための本発明のオーステナイト系Ｎ
ｉ−Ｃｒ４ｎ−Ｆｅ合金の構成は、オーステナイト系Ｎ
ｉ−Ｃｒ−Ｍｎ−Ｆｅ合金において、Ｎｉ含有量を４０
％以上とし、Ｍｎを２％以上含有してＮｉ当量が４１〜
６０％であり、Ｃｒ含有量は少なくとも２０％とし、Ｔ
ｉを０．５〜２．０％添加してＣｒ当量の最大値を３７
％としたことである。[Means for solving the problems] Austenitic N of the present invention for solving the above problems
The composition of the i-Cr4n-Fe alloy is austenitic N
In the i-Cr-Mn-Fe alloy, the Ni content is 40
% or more, contains 2% or more of Mn, and has a Ni equivalent of 41 to
60%, the Cr content is at least 20%, and the T
By adding 0.5 to 2.0% of i, the maximum value of Cr equivalent is 37
%.
［作用］
第４図は、オーステナイト系ステンレス鋼の水素脆化の
Ｎｉ当量依存性を示す。（但し、Ｑｏは、水素フリー材
の伸び、ＱＨは、水素添加材の伸びを示す）。[Function] FIG. 4 shows the dependence of hydrogen embrittlement of austenitic stainless steel on Ni equivalent. (However, Qo indicates the elongation of the hydrogen-free material, and QH indicates the elongation of the hydrogenated material).
また、第５図は、インコネル６００およびハステロイス
等のＮｉ基合金の水素脆化率に及ぼすＮｉ量の影響を示
す。Moreover, FIG. 5 shows the influence of the amount of Ni on the hydrogen embrittlement rate of Ni-based alloys such as Inconel 600 and Hastelloyce.
第４図および第５図から、水素脆化率には、Ｎｉ当量あ
るいはＮｉ量依存性があり、Ｎｉ含有量を、４０〜６０
％にすることにより、耐水素脆性のよい材料を得ること
ができる。From FIG. 4 and FIG. 5, the hydrogen embrittlement rate has a dependence on Ni equivalent or Ni amount, and when the Ni content is increased from 40 to 60
%, a material with good hydrogen embrittlement resistance can be obtained.
第６図および第７図から、鋭敏化あるいは、中性子照射
により、結晶粒界近傍にＣｒ量欠乏層が生成することが
わかる。一般に、Ｃｒ含有量が、約１５％以下になると
耐食性がいちじるしく低下するといわれている。It can be seen from FIGS. 6 and 7 that a Cr-deficient layer is generated near the grain boundaries due to sensitization or neutron irradiation. Generally, it is said that when the Cr content is less than about 15%, the corrosion resistance decreases significantly.
また、鋭敏化によるＣｒ量欠乏層の生成は、ＯｒとＣの
結合したクロム炭化物の析出によるものであり、結晶粒
界近傍のＣｒ量の欠乏の原因となるＣ量を、製造上許容
可能な限り低くした方がよい。すなわちＣ含有量を０．
０２％以下とした。In addition, the formation of a Cr-deficient layer due to sensitization is due to the precipitation of chromium carbide, which is a combination of Or and C. It is better to keep it as low as possible. In other words, the C content is set to 0.
0.02% or less.
従来は、このＣｒ欠乏を補うために、約１０％のＣｒを
上積みして添加し、耐食性を確保するようにしていた。Conventionally, in order to compensate for this Cr deficiency, approximately 10% Cr was added in order to ensure corrosion resistance.
本発明では、このＣｒ欠乏を、新規にＴｉを添加するこ
とにより防止し、添加するＣｒ量を節約した上耐食性を
確保することにある。The present invention aims to prevent this Cr deficiency by newly adding Ti, save the amount of Cr added, and ensure corrosion resistance.
鋭敏化によるＣｒの欠乏は、粒界近傍部でのＣｒ炭化物
の生成によっており、これを防止するためには、Ｃとの
結合力がＣｒよりも強いＴｉの添加が有効であり、その
添加量は、Ｃ量の約５倍がよいと云われている。したが
って、本発明では、Ｃ量が０．０２％以下なので、上記
のＴｉ添加量を約０．１％とし、若干の余裕をみて、Ｔ
ｉ量は０．５％（下限）とした。また、Ｔｉのオーステ
ナト基地に対する固溶度を考慮して、上限を２゜０％と
した。Cr deficiency due to sensitization is caused by the formation of Cr carbides near the grain boundaries. To prevent this, it is effective to add Ti, which has a stronger bonding force with C than Cr, and its addition amount It is said that about 5 times the amount of C is good. Therefore, in the present invention, since the C amount is 0.02% or less, the above Ti addition amount is set to about 0.1%, and with a slight margin, T
The amount of i was set to 0.5% (lower limit). Further, in consideration of the solid solubility of Ti in the austenite base, the upper limit was set to 2.0%.
一方、中性子照射により生じる粒界のＣｒ欠乏は、照射
誘起偏析によるものである。これは、鋭敏化によるＣ欠
乏とは異なり、Ｃｒ炭化物の生成は伴わない。これを防
止するためには、Ｃｒよりも原子半径の大きいＴｉを添
加することにより奏功することが可能である。それは、
Ｔｉが中性子照射により生成する過剰の原子空孔を、Ｃ
ｒよりも優先的にトラップしたり、粒界からＣｒよりも
優先的に欠乏するためである。On the other hand, Cr deficiency at grain boundaries caused by neutron irradiation is due to irradiation-induced segregation. This differs from C deficiency due to sensitization and does not involve the formation of Cr carbides. This can be effectively prevented by adding Ti, which has a larger atomic radius than Cr. it is,
Excess atomic vacancies generated by Ti due to neutron irradiation are replaced by C
This is because Cr is trapped more preferentially than r, or is depleted from grain boundaries more preferentially than Cr.
Ｔｉ添加の有無による粒界のＣｐ濃度変化の差異を示す
１実験例を第１図に示す。例えば、Ｔｉを１．５％添加
することにより、Ｃｒの粒界における欠乏を大幅に改善
することができることがわかる。FIG. 1 shows an experimental example showing the difference in the change in Cp concentration at grain boundaries depending on the presence or absence of Ti addition. For example, it can be seen that by adding 1.5% Ti, the deficiency of Cr at grain boundaries can be significantly improved.
第２図は、デュロングの組織図である。材料の化学成分
よりＣｒ当量［Ｃｒｅｑ＝＝（：ｒ＋Ｍｏ＋１．５ＸＳ
ｉ＋０．５ＸＮｂ （％）］と、Ｎｉ当量［Ｎ１ｅｑ
＝Ｎｉ＋３０ＸＣ＋３０ＸＮ＋０゜５ＸＭｎ（％）］を
求め、その図より常温の組織を推定することができる。Figure 2 is Dulong's organizational chart. From the chemical composition of the material, the Cr equivalent [Creq==(:r+Mo+1.5XS
i+0.5XNb (%)] and Ni equivalent [N1eq
=Ni+30XC+30XN+0°5XMn (%)], and the structure at room temperature can be estimated from the figure.
第２図において、例えば、Ｎｉ当量を４１％とした時に
は、Ｃｒ当量が３７％を超えると、材料の金属組織は、
（オーステナイト相＋フェライト相）の２相組織となリ
オーステナイト相とフェライト相の単相組織に比べて加
工性が低下する。このことを考慮して、Ｃｒ当量は、最
大３７％としてオーステナイト単相組織とした（範囲５
）。In Figure 2, for example, when the Ni equivalent is 41% and the Cr equivalent exceeds 37%, the metallographic structure of the material is
It has a two-phase structure of (austenite phase + ferrite phase), and the workability is lower than that of a single-phase structure of reaustenite phase and ferrite phase. Taking this into consideration, the Cr equivalent was set to a maximum of 37% to create an austenite single phase structure (range 5
).
［実施例コ
アー
本発明の１実施例として、Ｎ１＝４０％、Ｃｒ＝２０％
、Ｍ ｎ ＝ ２０％、Ｔｉ＝１％、Ｆｅ＝１８．９８
％、Ｃ＝０．０２％の合金材料について説明する。[Example Core As an example of the present invention, N1=40%, Cr=20%
, M n = 20%, Ti = 1%, Fe = 18.98
%, an alloy material with C=0.02% will be explained.
この場合のＮｉ当量およびＣｒ当量はそれぞれ以下のよ
うになる。The Ni equivalent and Cr equivalent in this case are as follows.
Ｎｉ当量＝Ｎｉ＋３０ＸＣ＋３０ＸＮ＋０．５Ｍｎ＝４
０＋３０Ｘ０．０２＋０．５Ｘ２０＝５０．６％
Ｃｒ当量＝Ｃｒ＋Ｍｏ＋０．５ＸＳｉ＋０．５ｘＮｂ＝
２０＝２０％
となりデュロングの組織図（第２図）上にプロットする
と点４となり、室温でオーステナイト単相の領域に存在
するので組織上は安定であり、また加工性も良好である
。また、第４図、第５図からも水素脆性のないことがわ
かる。Ni equivalent = Ni + 30XC + 30XN + 0.5Mn = 4
0+30X0.02+0.5X20=50.6% Cr equivalent=Cr+Mo+0.5XSi+0.5xNb=
20=20%, and when plotted on Dulong's structure diagram (Figure 2), it becomes point 4, and since it exists in the austenite single phase region at room temperature, it is structurally stable and has good workability. Furthermore, it can be seen from FIGS. 4 and 5 that there is no hydrogen embrittlement.
熱鋭敏化による粒界のＣｒ欠乏層の生成に対しては、Ｔ
ｉが０％（０，０２％）の５倍（ｏ、１％）以上添加さ
れており１問題はない。For the formation of Cr-depleted layers at grain boundaries due to thermal sensitization, T
Since i is added in an amount more than 5 times (o, 1%) than 0% (0.02%), there is no problem.
また、本実施例の合金材料を原子炉炉内構造物として使
用した場合について説明する。Further, a case will be described in which the alloy material of this example is used as a reactor internal structure.
炉内構造物の通常の使用環境条件は、２５０〜３００℃
（平均２８８℃）の炉水（純水）中で、中性子照射量（
’％１０″２ｎ ／ ａ＃）を受けると共に、平均約７
１Ｋｇ／ａｆｆの加圧下にあり、３０〜４０年間の耐用
が必要である。The normal operating environment conditions for reactor internals are 250 to 300°C.
(average 288℃) in reactor water (pure water), the neutron irradiation amount (
'%10''2n/a#) with an average of about 7
It is under pressure of 1 kg/af and must last for 30 to 40 years.
原子炉内で使用中には、炉内構造材は中性子照射を受け
て、その結果としてその結晶粒界のＣｒ量が減少するこ
とについては、すでに述べた通りである。As already mentioned, during use in a nuclear reactor, the reactor structural material is irradiated with neutrons, and as a result, the amount of Cr in its grain boundaries is reduced.
第３図は、本実施例の合金材料が中性子照射量ｌＸｌ０
”ｎ／ａｌ？を受けた場合の結晶粒界近傍部のＣｒ量の
減少状況を示す。Figure 3 shows that the alloy material of this example has a neutron irradiation amount lXl0
This figure shows how the amount of Cr decreases in the vicinity of grain boundaries when subjected to "n/al?".
これかられかるように、粒界においてＣｒの欠乏が若干
認められる程度である。すなわち、Ｃｒ量は、平均２０
％から１８％に減少した程度であり、従来例に比べて著
しく改善されたことになる。As will be seen, a slight Cr deficiency is observed at the grain boundaries. That is, the average amount of Cr is 20
% to 18%, which is a significant improvement over the conventional example.
つぎに、耐水素脆性について考える。上記のような原子
炉環境中で、オーステナイト系不銹鋼（ＳＵＳ３０４、
ＳＵＳ ３１６など）を使用すると、鋼中の水素含有量
が増大することが知られている。Next, let's consider hydrogen embrittlement resistance. In the above-mentioned nuclear reactor environment, austenitic stainless steel (SUS304,
It is known that when steel (such as SUS 316) is used, the hydrogen content in the steel increases.
例えば、使用前の鋼中の水素含有量は約５ｐｐｍである
が、上記環境中では、１５〜３５ＰＰｍに増大すること
が認められている。一方、本実施例の４０ Ｎ ｉ −
２０Ｃｒ −２０Ｍ ｎ −Ｉ Ｔ ｊ、 −２０Ｆｅ
合金では、上記環境中で水素含有量が５０ｐｐｍに増大
した場合でも、第４図に示した通り、水素脆化が起こら
ないことがわかる。オーステナイト不銹鋼の場合には、
水素脆化率はきわめて大きいことが認められる。For example, the hydrogen content in steel before use is about 5 ppm, but it has been observed that in the above environment it increases to 15-35 ppm. On the other hand, 40 N i − of this example
20Cr -20M n -IT j, -20Fe
As shown in FIG. 4, it can be seen that hydrogen embrittlement does not occur in the alloy even when the hydrogen content increases to 50 ppm in the above environment. In the case of austenitic stainless steel,
It is recognized that the hydrogen embrittlement rate is extremely high.
以上説明したように、本実施例の４ＯＮｉ−２０Ｃｒ−
２０Ｍｎ−Ｔｉ−２０Ｆｅ合金を炉内構造材として炉内
で使用した場合は、中性子照射による腐食および水素脆
化による材質の劣化を防止することができる。As explained above, the 4ONi-20Cr-
When the 20Mn-Ti-20Fe alloy is used as a structural material in the furnace, corrosion due to neutron irradiation and deterioration of the material due to hydrogen embrittlement can be prevented.
また、加工性に関しては、既に説明したように、Ｎｉ−
Ｃｒ不銹鋼においては、Ｎｉ量が多い方が、加工時にマ
ルテイサイト相の生成が少なく、加工性がよいことは実
証されている。Regarding workability, as already explained, Ni-
In Cr stainless steel, it has been proven that the higher the Ni content, the less martesite phase is formed during processing and the workability is better.
なお、ＮｉおよびＣｒは、有用かつ貴重な物質なので極
力節約して、少量の添力ａで効力を発揮するようにせね
ばならない。Note that Ni and Cr are useful and valuable substances, so they must be saved as much as possible so that they can be effective with a small amount of addition a.
［発明の効果コ
本発明によれば、ＮｉおよびＣｒ節約型の材料で、耐水
素脆性は良好であり、かつ鋭敏化あるいは中性子照射に
よるＣｒ欠乏層の生成に伴なう耐食性の低下がなく、加
工性のすぐれた材料を提供することができる。[Effects of the Invention] According to the present invention, the material is Ni- and Cr-saving, has good hydrogen embrittlement resistance, and does not suffer from deterioration in corrosion resistance due to sensitization or the formation of a Cr-depleted layer due to neutron irradiation. A material with excellent workability can be provided.
第１図は、照射による結晶粒界のＣｒ欠乏に及ぼすＴｉ
添加効果説明図、第２図は、デュロングの組織図、第３
図は、本発明の実施例材料における中性子照射による粒
界近傍のＣｒ欠乏状況を示す線図、第４図は、オーステ
ナイト系ステンレス鋼の水素脆化率とＮｉ当量の関係線
図、第５図は、Ｎｉ−Ｃｒ合金の水素脆化率とＮｉ量と
の関係線図、第６図は、５ＵＳ３０４の鋭敏化による結
晶粒界のＣｒ欠乏状況説明用線図、第７図は、５ＵＳ３
０４の中性子照射による結晶粒界のＣｒ欠乏状況を説明
する線図である。
〈符号の説明〉
１・・・平滑材の試験曲線、２・・・切欠材の試験曲線
、３・・・鋭敏化材の試験曲線、４・・・デュロング図
上に示した本実施例合金のＣｒ、Ｎｉ量。Figure 1 shows the effect of Ti on Cr deficiency at grain boundaries due to irradiation.
Addition effect explanatory diagram, Figure 2 is Dulong's organizational chart, Figure 3.
The figure is a diagram showing the Cr deficiency state near the grain boundaries due to neutron irradiation in the example materials of the present invention, Figure 4 is the relationship diagram between hydrogen embrittlement rate and Ni equivalent of austenitic stainless steel, and Figure 5 is is a relationship diagram between hydrogen embrittlement rate and Ni content of Ni-Cr alloy, Figure 6 is a diagram for explaining the state of Cr deficiency in grain boundaries due to sensitization of 5US304, and Figure 7 is a diagram for explaining the state of Cr deficiency in grain boundaries due to sensitization of 5US304.
FIG. 2 is a diagram illustrating the state of Cr deficiency in grain boundaries due to neutron irradiation in No. 04. <Explanation of symbols> 1... Test curve of smooth material, 2... Test curve of notched material, 3... Test curve of sensitized material, 4... Alloy of the present example shown on the Dulong diagram The amount of Cr and Ni.
Claims (1)
いて、Ｎｉ含有量を４０％以上とし、Ｍｎを２％以上含
有してＮｉ当量が４１〜６０％であり、Ｃｒ含有量は少
なくとも２０％とし、Ｔｉを０．５〜２．０％添加して
Ｃｒ当量の最大値を３７％としたことを特徴とするオー
ステナイト系Ｎｉ−Ｃｒ−Ｍｎ−Ｆｅ合金。 ２、請求項１記載の合金において、Ｃ含有量を、最大０
．０２％としたことを特徴とするオーステナイト系Ｎｉ
−Ｃｒ−Ｍｎ−Ｆｅ合金。[Claims] 1. In an austenitic Ni-Cr-Mn-Fe alloy, the Ni content is 40% or more, the Mn is 2% or more, the Ni equivalent is 41 to 60%, and the Cr content is 40% or more. is at least 20%, and Ti is added in an amount of 0.5 to 2.0% to give a maximum Cr equivalent of 37%. 2. In the alloy according to claim 1, the C content is at most 0.
．． Austenitic Ni characterized by having 0.02%
-Cr-Mn-Fe alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30868590A JPH04183837A (en) | 1990-11-16 | 1990-11-16 | Austenite system ni-cr-mn-fe alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30868590A JPH04183837A (en) | 1990-11-16 | 1990-11-16 | Austenite system ni-cr-mn-fe alloy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04183837A true JPH04183837A (en) | 1992-06-30 |
Family
ID=17984055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30868590A Pending JPH04183837A (en) | 1990-11-16 | 1990-11-16 | Austenite system ni-cr-mn-fe alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04183837A (en) |
-
1990
- 1990-11-16 JP JP30868590A patent/JPH04183837A/en active Pending
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