JPS62297443A - Austenitic stainless steel having superior hot workability and high corrosion resistance - Google Patents
Austenitic stainless steel having superior hot workability and high corrosion resistanceInfo
- Publication number
- JPS62297443A JPS62297443A JP14028686A JP14028686A JPS62297443A JP S62297443 A JPS62297443 A JP S62297443A JP 14028686 A JP14028686 A JP 14028686A JP 14028686 A JP14028686 A JP 14028686A JP S62297443 A JPS62297443 A JP S62297443A
- Authority
- JP
- Japan
- Prior art keywords
- corrosion resistance
- hot workability
- stainless steel
- austenitic stainless
- 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.)
- Granted
Links
- 230000007797 corrosion Effects 0.000 title claims abstract description 64
- 238000005260 corrosion Methods 0.000 title claims abstract description 64
- 229910000963 austenitic stainless steel Inorganic materials 0.000 title claims abstract description 10
- 229910052796 boron Inorganic materials 0.000 claims abstract description 13
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 10
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 10
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 7
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 7
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims description 5
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 abstract description 11
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- 229910052799 carbon Inorganic materials 0.000 abstract 2
- 229910000831 Steel Inorganic materials 0.000 description 17
- 239000010959 steel Substances 0.000 description 17
- 239000011651 chromium Substances 0.000 description 15
- 238000001556 precipitation Methods 0.000 description 11
- 238000012360 testing method Methods 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 229910000765 intermetallic Inorganic materials 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- UFGZSIPAQKLCGR-UHFFFAOYSA-N chromium carbide Chemical compound [Cr]#C[Cr]C#[Cr] UFGZSIPAQKLCGR-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000866 electrolytic etching Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 229910003470 tongbaite Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
３、発明の詳細な説明
（産業上の利用分野）
本発明は、熱間加工性に優れる高耐食オーステナイトス
テンレス鋼に関し、特に海水熱交換器や製紙プラントの
漂白プロセス用材料として用いるときに好適な、いわゆ
る耐酸性、耐孔食性や耐すきま腐食性、なかでも、塩化
物による腐食に対して優れた抵抗性を有すると共に熱間
加工性にも優れるステンレス鋼について提案する。Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a highly corrosion-resistant austenitic stainless steel with excellent hot workability, particularly for use in seawater heat exchangers and bleaching processes in paper manufacturing plants. We propose stainless steel, which is suitable for use as a material, as it has so-called acid resistance, pitting corrosion resistance, and crevice corrosion resistance, especially excellent resistance to corrosion caused by chlorides, as well as excellent hot workability. .
（従来の技術）
近年、耐食材料に要求される品質のレベルは、安全性や
メインテナンスフリーによるコストパーフォーマンスの
観点から非常に高くなっており、これに伴いステンレス
鋼も高級化の要請が畜まっている。(Conventional technology) In recent years, the level of quality required for corrosion-resistant materials has become extremely high from the viewpoint of safety and cost performance due to maintenance-free construction. ing.
かかるステンレス鋼の耐食性については、孔食すきま腐
食、応力腐食割れ、全面腐食、粒界腐食等の指標がある
。これらの品質指標の中で特に孔食、すきま腐食は、ス
テンレス鋼の用途に関連して最も多く直面する指標であ
り、特に海水熱交換器などのように塩素イオン濃度が高
く、かつ温度も高くなる環境条件でもこれらの耐食性が
良好なものが、とりわけ重要である。Regarding the corrosion resistance of stainless steel, there are indicators such as pitting crevice corrosion, stress corrosion cracking, general corrosion, and intergranular corrosion. Among these quality indicators, pitting corrosion and crevice corrosion are the indicators most often encountered in connection with stainless steel applications, especially those with high chloride ion concentrations and high temperatures, such as seawater heat exchangers. It is especially important to have good corrosion resistance under these environmental conditions.
そこで、従来、耐孔食性やすきま腐食性を向上させる方
法として、ＣｒおよびＭｏ含有量を高くすることが知ら
れていた。しかし合金元素としてのＣｒ。Therefore, it has been known to increase the Cr and Mo contents as a method of improving pitting corrosion resistance and crevice corrosion resistance. However, Cr as an alloying element.
Ｍｏ含有量を高くすると、σ相などの金属間化合物が析
出し易く、耐食性の面などで安定した品質が得られがた
（なり、その上、熱間加工性が劣化して製造上の障害に
なるという問題が残る。When the Mo content is increased, intermetallic compounds such as the σ phase tend to precipitate, making it difficult to obtain stable quality in terms of corrosion resistance. The problem remains.
従って、高Ｃｒ高Ｍｏを含有する高合金については、耐
食性の他σ相析出に対する組織安定性、熱間加工性を考
慮した総合的な合金設計が必要であり、この意味で上述
の既知技術は不充分である。Therefore, for high alloys containing high Cr and high Mo, a comprehensive alloy design is required that takes into consideration not only corrosion resistance but also structural stability against σ phase precipitation and hot workability. It is insufficient.
この点を克服する技術として従来、特公昭６０−２３１
８５号として熱間加工性をも改善したものが提案されて
いる。しかし、この従来技術も量産化を考えた場合挽め
で高い加工性が要求されるので改善の効果はなお不充分
である。Conventionally, as a technique to overcome this point,
No. 85, which also has improved hot workability, has been proposed. However, this conventional technique is still insufficient in terms of improvement since high workability is required in terms of mass production.
（発明が解決しようとする問題点）
一般に、グ相など金属間化合物が析出すると、機械的性
質の劣化とともに耐食性も劣化する。従って、オーステ
ナイト組織を安定化させる必要があり、ＮｉやＮなどオ
ーステナイト生成元素を所定量以上含有させねばならな
い。しかも、工業用材料としては、耐食性や機械的性質
などの品質の他に製造が容易であることは不可欠な要因
であり、特にＭｏやＣｒを多（含有すると熱間加工性が
低下するので、量産化のためにはこの点に関しての解決
が必要へなるのである。(Problems to be Solved by the Invention) Generally, when intermetallic compounds such as a gray phase are precipitated, not only mechanical properties deteriorate but also corrosion resistance deteriorates. Therefore, it is necessary to stabilize the austenite structure, and it is necessary to contain a predetermined amount or more of austenite-forming elements such as Ni and N. Moreover, as an industrial material, in addition to qualities such as corrosion resistance and mechanical properties, ease of production is an essential factor, and in particular, high content of Mo and Cr (because hot workability decreases, For mass production, it is necessary to solve this problem.
要するに、本発明は５ＵＳ３０４や５ＵＳ３１６よりも
一段と優れた高Ｃｒ、 Ｍｏ含有の高耐食合金の提案、
すなわち耐食性、σ相析出に対する組織安定性および熱
間加工性のいずれの点においても優れたオーステナイト
ステンレス鋼を提案することを目的としており、特に量
産化に必要な高い熱間加工性を有するオーステナイトス
テンレス鋼を提供する。In short, the present invention proposes a highly corrosion resistant alloy containing high Cr and Mo that is even better than 5US304 and 5US316.
In other words, the aim is to propose austenitic stainless steels that are excellent in terms of corrosion resistance, structural stability against σ phase precipitation, and hot workability, and in particular, austenitic stainless steels that have high hot workability necessary for mass production. Provide steel.
（問題点を解決するための手段）
本発明は、耐孔食性、耐すきま腐食性など耐食性に優れ
かつ、組織的にも異相の析出が出にくいオーステナイト
組織について、さらに熱間加工性にも優れたものを得よ
うとする場合に、鋼中の酸素レベルが低いときＢが極め
て有効に作用して効果があると言う知見に基づいて完成
を見たものである。(Means for Solving the Problems) The present invention provides an austenitic structure that has excellent corrosion resistance such as pitting corrosion resistance and crevice corrosion resistance, and is difficult to form heterogeneous phase precipitation in terms of structure, and also has excellent hot workability. This work was completed based on the knowledge that B acts extremely effectively and is effective when the oxygen level in the steel is low.
すなわち、高Ｃｒ高Ｍｏ含有鋼だと高温強度が大きくな
り加工性が劣化し、熱間加工時に粒界割れが生じ易くな
る。しかし、Ｂを添加するとこのＢが粒界に析出して熱
間加工性を向上させる。しかしこのＢは、鋼中の酸素と
も結びつき易いため、酸素レベルが高いと、粒界を強化
するフリーＢが少なくなり、Ｂの効果が充分発揮されな
くなる。That is, high-Cr, high-Mo content steel increases high-temperature strength, deteriorates workability, and tends to cause intergranular cracking during hot working. However, when B is added, this B precipitates at grain boundaries and improves hot workability. However, this B easily combines with oxygen in the steel, so if the oxygen level is high, there will be less free B that strengthens grain boundaries, and the effect of B will not be fully exhibited.
いわゆる発明者らは、Ｂ添加による熱間加工性に対する
効果が、０レベルによって変わり、それが６０ｐｐｍ以
下になると著しく向上することを見い出し、次の事項を
骨子とする発明を完成した。The so-called inventors have discovered that the effect of B addition on hot workability changes depending on the 0 level, and that it is significantly improved when it is 60 ppm or less, and has completed an invention based on the following points.
すなわち、本発明は、
Ｃ≦０．０３０譬ｔ％、 Ｓｉ≦２．０智ｔ％Ｍｎ≦１
．０ｗｔ％、 Ｃｒ：１９〜３０ｗｔ％Ｎｉ：２０〜
３０ｗｔ％、
Ｍｏ ： ３．５〜７．０ｗｔ％、およびＢ≦０．０１
０ｗｔ％を基本成分として含有し、副成分として、也Ｖ
またはＣｕの少なくとも一種を合計で２．０ｗｔ％以下
含有し、さらにまた、Ｍｇを０．０５ ｗｔ％ｔ％含有
し、
そして、常温海水中での耐すきま腐食性を付与するため
に、
Ｃｒ ＋ ３Ｍｏ ＋ ２０Ｎ≧４０なる条件を採用し
、また、組織の安定性のために
Ｃｒ ＋ ２Ｍｏ ＋ ８Ｓｉ ＋ ２Ｍｎ ≦ Ｎ
ｉ＋５０Ｎ＋６．４なる条件を採用し、そして、
Ｎ≦０．４０ ｗｔ％、 ０≦０．００６０ｗｔ％Ｐ≦
０．０４０ｗｔ％、 Ｓ≦０．００５ｗｔ％であって、
残部がＦｅおよび不可避的不純物よりなる熱間加工性に
優れる高耐食オーステナイトステンレス鋼を提案する。That is, the present invention provides the following conditions: C≦0.030 t%, Si≦2.0, t% Mn≦1
．． 0wt%, Cr:19~30wt%Ni:20~
30wt%, Mo: 3.5-7.0wt%, and B≦0.01
Contains 0wt% as a basic component, and as a subcomponent,
or containing at least one type of Cu in a total of 2.0 wt% or less, furthermore containing 0.05 wt%t% of Mg, and in order to provide crevice corrosion resistance in room temperature seawater, Cr + The condition 3Mo + 20N≧40 was adopted, and for the stability of the structure, Cr + 2Mo + 8Si + 2Mn ≦N
The conditions of i+50N+6.4 are adopted, and N≦0.40wt%, 0≦0.0060wt%P≦
0.040wt%, S≦0.005wt%,
We propose a highly corrosion-resistant austenitic stainless steel with excellent hot workability, the balance of which is Fe and unavoidable impurities.
（作 用）
以下に本発明オーステナイトステンレスロの成分組成限
定の理由について説明する。(Function) The reason for limiting the composition of the austenitic stainless steel of the present invention will be explained below.
Ｃ： ０．０３ｗｔ％（以下は「％」で略記する）より
高いと、溶接などの熱形容部にクロム炭化物が析出し粒
界が鋭敏化して耐食性が劣化する。C: If it is higher than 0.03 wt% (hereinafter abbreviated as "%"), chromium carbide will precipitate in heat-forming parts such as welding, grain boundaries will become sharp, and corrosion resistance will deteriorate.
Ｓｉ：耐孔食性など耐食性に有効ではあるが、２．０％
を超えると、σ相などの金属間化合物の析出を著しく促
進し、かえって耐食性が劣化したり靭性が劣化する。Si: Effective for corrosion resistance such as pitting corrosion resistance, but 2.0%
If it exceeds this value, the precipitation of intermetallic compounds such as σ phase will be significantly promoted, and corrosion resistance and toughness will deteriorate on the contrary.
Ｍｎ ： １．０％を超えると、耐食性が劣化するとと
もに、σ相などの析出を促進する。Mn: If it exceeds 1.0%, corrosion resistance deteriorates and precipitation of σ phase and the like is promoted.
Ｃｒ：耐食性に不可欠の元素で、１９％を下廻ると高、
耐食合金の特徴が失なわれる。一方、Ｃｒはσ相などの
生成を促進し、３０％を超えると組織安定化のために高
価なＮｉなとの多量添加が必要となる。Cr: An essential element for corrosion resistance, if it is less than 19%, it is high.
Corrosion-resistant alloy properties are lost. On the other hand, Cr promotes the formation of σ phase and the like, and when it exceeds 30%, it becomes necessary to add a large amount of expensive Ni or the like to stabilize the structure.
Ｎｉ：σ相など異相の析出を抑える組織安定化元素とし
て極めて有効であり、２０％を下廻ると組織が不安定と
なる。３０％を超える添加は高価となる。Ni: Extremely effective as a structure-stabilizing element that suppresses the precipitation of foreign phases such as σ phase, and when it falls below 20%, the structure becomes unstable. Addition of more than 30% is expensive.
Ｍｏ ： Ｃｒと同様に耐食性向上に不可欠な元素であ
る。Mo: Like Cr, it is an element essential for improving corrosion resistance.
その含有量が３，５％を下廻ると、本来の耐食性が得ら
れない。しかし、Ｃｒと同様、７％を超えるとσなどの
異相の析出を促進するので組織安定化のためにＮｉが多
量に必要となる。If the content is less than 3.5%, the original corrosion resistance cannot be obtained. However, like Cr, if it exceeds 7%, precipitation of foreign phases such as σ is promoted, so a large amount of Ni is required to stabilize the structure.
Ｂ：熱間加工性向上に不可欠な元素である。ただし、０
．０１０％を超えると逆に加工性を劣化させる。B: An essential element for improving hot workability. However, 0
．． If it exceeds 0.010%, workability will be deteriorated.
Ｗ、Ｖ：耐食性に有効である。しかし、いずれもσ相析
出を促進する。また２％を超える添加は組織を不安定と
しまた価格が高くなる。W, V: Effective for corrosion resistance. However, both promote σ phase precipitation. Further, addition of more than 2% makes the structure unstable and increases the price.
Ｃｕ：耐食性に有効である。しかし、２％を超えると熱
１間加工性を劣化させる。Cu: Effective for corrosion resistance. However, when it exceeds 2%, hot workability deteriorates.
Ｍｇ：Ｓを固定し、熱間加工性を向上する。ただし、０
．０５％を超えると、高温で粒界に化合物を析出し逆に
加工性を劣化する。Mg: Fixes S and improves hot workability. However, 0
．． If it exceeds 0.05%, compounds will precipitate at grain boundaries at high temperatures, and workability will deteriorate.
Ｎ：組織安定化および耐孔食性に極めて有効である。た
だし、０．４０％を超える添加は、鋳込み時のプローホ
ールの生成、高温強度が著しく高くなることによる加工
性の劣化をまねく。N: Very effective for structure stabilization and pitting corrosion resistance. However, addition of more than 0.40% leads to formation of plowholes during casting and deterioration of workability due to significantly increased high-temperature strength.
０：この酸素は、低いほど熱間加工性は良くなり、特に
０．００６０％以下になると、Ｂの効果を著しく高くし
て極めて優れる熱間加工性が得られる（第２図参照）。0: The lower the oxygen content, the better the hot workability. Particularly, when it is 0.0060% or less, the effect of B is significantly increased and extremely excellent hot workability is obtained (see Figure 2).
Ｐ ： ０．０４０％を超えると熱間加工性、溶接性を
劣化する。P: If it exceeds 0.040%, hot workability and weldability will deteriorate.
Ｓ ： ０．００５％を超えると熱間加工性、溶接性
、耐食性を著しく劣化させる。好ましくは０．００１％
以下が良い。S: If it exceeds 0.005%, hot workability, weldability, and corrosion resistance will be significantly deteriorated. Preferably 0.001%
The following is good.
（実施例）
次に本発明鋼の特性について調べた実施例について説明
する。(Example) Next, an example in which the characteristics of the steel of the present invention were investigated will be described.
この実施例で用いた供試材の成分組成を第１表に示す。Table 1 shows the composition of the sample materials used in this example.
この供試材（本発明鋼、比較鋼）は、誘導炉にて１０ｋ
ｇの鋼塊とし、これを熱間鍛造した後焼鈍、熱間圧延−
焼鈍して得た。特性試験は次の方法に従った。This test material (invention steel, comparative steel) was heated to 10k in an induction furnace.
A steel ingot of g is made into a steel ingot, which is hot forged, then annealed and hot rolled.
Obtained by annealing. Characteristic tests were conducted in accordance with the following method.
（１）熱間加工性評価： （７０ｔＸ１００ｗｘ １ｍ
ｍ 、 １０ｋｇインゴットを１２５０℃に加熱し、ハ
ンマーにて１０ｔ Ｘ １００ｗ ｘ ｌにし、端部に
生じた最大割れ長さで評価した。(1) Hot workability evaluation: (70tX100wx 1m
A 10 kg ingot was heated to 1250° C. and made into 10 t×100 w×l with a hammer, and evaluated based on the maximum crack length that occurred at the end.
（２）組織安定性： （２ｔ）ｍｍｍ板体体化処理材ｌ
０ＮＫＯＨで電解エツチングし、顕微鏡観察により、析
出物の量を格子点法により測定した。(2) Tissue stability: (2t)mmmm plate material l
Electrolytic etching was performed with 0NKOH, and the amount of precipitates was measured by the lattice point method by microscopic observation.
（３）耐食性
（ｉｉ ）すきま腐食＝１０％ＦｅＣ１＋・６ＨｚＯ＋
ＮＨＣｌ。(3) Corrosion resistance (ii) Crevice corrosion = 10%FeC1+・6HzO+
NHCl.
４ｏ１、□２ｈｒ １６
（ｉｉｉ ）全面腐食：５％Ｈ２ＳＯ４、沸騰６ｈいず
、れも腐食度で評価した。すきま腐食試験片を第１図に
示す。図示の１は輪ゴム、２はガスケント（テフロン柱
）である。4o1, □2hr 16 (iii) General corrosion: 5% H2SO4, boiling for 6 hours, both were evaluated by corrosion degree. Figure 1 shows the crevice corrosion test piece. In the figure, 1 is a rubber band, and 2 is a gasket (Teflon column).
以下に試験の結果についてのべる。The test results are described below.
（１）熱間加工性について、
第１表に示すように、本発明名調は、いずれにおいても
、熱間鍛造で割れが発生しておらず：熱間加工性は極め
て良好であった。一方、比較名調においては、ボロンを
含有しない鋼Ａ、 Ｃおよびボロンを含有するが鋼中
の酸素含有量が６０ｐｐｍを超えるＭ（Ｂ、Ｅ）あるい
は、ボロン含有量が０．０１％を超えるｍ （Ｄ、Ｆ、
Ｇ）のいずれも割れが発生している。特に、鋼中酸素含
有量が高くなると加工性の改善に効果のあるボロンが有
効に働らくなることが判った。(1) Regarding hot workability, as shown in Table 1, no cracks occurred during hot forging in any of the samples of the present invention: the hot workability was extremely good. On the other hand, in comparison, steels A and C do not contain boron, and M (B, E) contains boron but the oxygen content in the steel exceeds 60 ppm, or the boron content exceeds 0.01%. m (D, F,
G) Cracks have occurred in both cases. In particular, it has been found that boron, which is effective in improving workability, becomes less effective when the oxygen content in the steel increases.
（２）組織安定性と耐食性について
ａ１ａ安定性は、鋼に析出したσ相等の析出相量で評価
し、その結果を第１表に示す。また、耐食性については
第２表にその結果を示す。本発明鋼の場合はいずれも析
出相量は１％以下で低く、耐食性についても孔食試験、
すきま腐食試験で腐食度は０．１ｇ／ｍ”・ｈ以下と低
く、全面腐食試験で２．０ｇ／ｍ２・ｈ以下であった。(2) Regarding structural stability and corrosion resistance, a1a stability was evaluated by the amount of precipitated phases such as σ phase precipitated in the steel, and the results are shown in Table 1. Regarding corrosion resistance, the results are shown in Table 2. In the case of the steels of the present invention, the amount of precipitated phases is low at 1% or less, and the corrosion resistance is also determined by pitting tests and tests.
The degree of corrosion was as low as 0.1 g/m''·h or less in the crevice corrosion test, and it was 2.0 g/m2·h or less in the full surface corrosion test.
これに対して、比較鋼は、析出相量は１％を超え、孔食
およびすきま腐食試験の腐食度は０．１ｇ／ｍ ｔ・ｈ
を超えており、耐酸性に対しても比較鋼Ａ、 Ｂは２ｇ
／ｍ”・ｈを超えていた。On the other hand, in the comparison steel, the amount of precipitated phase exceeds 1%, and the degree of corrosion in pitting and crevice corrosion tests is 0.1 g/m t・h.
The acid resistance of comparative steels A and B exceeds 2g.
/m”・h.
第２図は、この実施例の鋼について熱間加工性に及ぼす
ＢおよびＯ含有量の影響を調べた結果を示す図で、熱間
加工性は、Ｂおよび酸素量に依存し、Ｂは加工性改善に
有効であるが０．０１％を超えると、逆に加工性は劣化
し、また、Ｏ含有量が６０ｐｐｍを超えると加工性は著
しく劣化することが確められた。Figure 2 shows the results of investigating the effects of B and O contents on hot workability for the steel of this example.Hot workability depends on B and oxygen content, and B It was confirmed that O content is effective in improving properties, but if it exceeds 0.01%, processability deteriorates, and if O content exceeds 60 ppm, processability deteriorates significantly.
また、第３図は、σ析出量に及ぼす各元素の影響を示す
図で、
Ｃｒ＋２Ｍｏ＋８Ｓｉ＋２Ｍｎ＋Ｗ＋３Ｖ ＞ （Ｃｒ
＋Ｃｕ＋５０Ｎ＋６．４）になると析出量は急増するこ
とが判った。In addition, Fig. 3 is a diagram showing the influence of each element on the amount of σ precipitation. Cr+2Mo+8Si+2Mn+W+3V > (Cr
+Cu+50N+6.4), the amount of precipitation increases rapidly.
さらに第４図は、耐食性に及ぼす各元素の影響を調べた
もので、Ｃｒ ＋ ａＭｏ ＋２０Ｎが４０％以上で耐
食性が良くなることが確認できた。Furthermore, FIG. 4 shows an investigation of the influence of each element on corrosion resistance, and it was confirmed that corrosion resistance improved when Cr + aMo + 20N was 40% or more.
第 ２ 表
（発明の効果）
以上説明したように本発明によれば、Ｂと○の含有量を
厳しく調整するという本発明において特有な合金設計に
より、耐酸性の他、耐孔食、耐すきま腐食などの耐食性
に優れると共に熱間加工性にも優れたオーステナイトス
テンレス鋼を工業的に安価に得ることができる。Table 2 (Effects of the Invention) As explained above, according to the present invention, the unique alloy design of the present invention, in which the content of B and O is strictly controlled, provides not only acid resistance but also pitting corrosion resistance and crevice resistance. Austenitic stainless steel with excellent corrosion resistance and hot workability can be obtained industrially at low cost.
第１図の（ａｌ、 （ｂｌは、すきま腐食試験片の正面
図および側面図、
第２図は、熱間加工性に及ぼすＢ、○の影響を示すグラ
フ、
第３図は、σ相析出量と各成分組成との関係を示すグラ
フ、
第４図は、耐孔食性と各成分組成との関係を示すグラフ
である。
第１図
（ａ）
（ｂ）
第２図
５（′／ａ）Figure 1 (al, (bl) is a front view and side view of the crevice corrosion test piece, Figure 2 is a graph showing the influence of B and ○ on hot workability, Figure 3 is σ phase precipitation Figure 4 is a graph showing the relationship between pitting corrosion resistance and the composition of each component. Figure 1 (a) (b) Figure 2 5 ('/a) )
Claims (1)
１．０ｗｔ％、Ｃｒ：１９〜３０ｗｔ％Ｎｉ：２０〜３
０ｗｔ％、 Ｍｏ：３．５〜７．０ｗｔ％、および Ｂ≦０．０１０ｗｔ％を含有し、 Ｃｒ＋３Ｍｏ＋２０Ｎ≧４０ Ｃｒ＋２Ｍｏ＋８Ｓｉ＋２Ｍｎ≦Ｎｉ＋５０Ｎ＋６．４
であり、そして Ｎ≦０．４０ｗｔ％、０≦０．００６０ｗｔ％Ｐ≦０．
０４０ｗｔ％、Ｓ≦０．００５ｗｔ％であって、残部が
Ｆｅおよび不可避的不純物よりなる熱間加工性に優れる
高耐食オーステナイトステンレス鋼。 ２、Ｃ≦０．０３０ｗｔ％、Ｓｉ≦２．０ｗｔ％Ｍｎ≦
１．０ｗｔ％、Ｃｒ：１９〜３０ｗｔ％Ｎｉ：２０〜３
０ｗｔ％、 Ｍｏ：３．５〜７．０ｗｔ％、および Ｂ≦０．０１０ｗｔ％を含有し、かつ Ｗ、ＶまたはＣｕの少なくとも一種を合計で２．０ｗｔ
％以下含有し、 Ｃｒ＋３Ｍｏ＋２０Ｎ≧４０ Ｃｒ＋２Ｍｏ＋８Ｓｉ＋２Ｍｎ≦Ｎｉ＋５０Ｎ＋６．４
であり、そして Ｎ≦０．４０ｗｔ％、０≦０．００６０ｗｔ％Ｐ≦０．
０４０ｗｔ％、Ｓ≦０．００５ｗｔ％であって、残部が
Ｆｅおよび不可避的不純物よりなる熱間加工性に優れる
高耐食オーステナイトステンレス鋼。 ３、Ｃ≦０．０３０ｗｔ％、Ｓｉ≦２．０ｗｔ％Ｍｎ≦
１．０ｗｔ％、Ｃｒ：１９〜３０ｗｔ％Ｎｉ：２０〜３
０ｗｔ％、 Ｍｏ：３．５〜７．０ｗｔ％、および Ｂ≦０．０１０ｗｔ％を含有し、 Ｃｒ＋３Ｍｏ＋２０Ｎ≧４０ Ｃｒ＋２Ｍｏ＋８Ｓｉ＋２Ｍｎ≦Ｎｉ＋５０Ｎ＋６．４
Ｎ≦０．４０ｗｔ％、０≦０．００６０ｗｔ％Ｐ≦０．
０４０ｗｔ％、Ｓ≦０．００５ｗｔ％であって、残部が
Ｆｅおよび不可避的不純物よりなる熱間加工性に優れる
高耐食オーステナイトステンレス鋼。 ４、Ｃ≦０．０３０ｗｔ％、Ｓｉ≦２．０ｗｔ％Ｍｎ≦
１．０ｗｔ％、Ｃｒ：１９〜３０ｗｔ％Ｎｉ：２０〜３
０ｗｔ％、Ｍｏ：３．５〜７．０ｗｔ％Ｂ≦０．０１０
ｗｔ％、および Ｍｇ≦０．０５ｗｔ％を含有し、かつ Ｗ、ＶまたはＣｕの少なくとも一種を合計で２．０ｗｔ
％以下含有し、 Ｃｒ＋３Ｍｏ＋２０Ｎ≧４０ Ｃｒ＋２Ｍｏ＋８Ｓｉ＋２Ｍｎ≦Ｎｉ＋５０Ｎ＋６．４
であり、そして Ｎ≦０．４０ｗｔ％、０≦０．００６０ｗｔ％Ｐ≦０．
０４０ｗｔ％、Ｓ≦０．００５ｗｔ％であって、残部が
Ｆｅおよび不可避的不純物よりなる熱間加工性に優れる
高耐食オーステナイトステンレス鋼。[Claims] 1. C≦0.030wt%, Si≦2.0wt%Mn≦
1.0wt%, Cr: 19-30wt% Ni: 20-3
0 wt%, Mo: 3.5 to 7.0 wt%, and B≦0.010 wt%, Cr+3Mo+20N≧40 Cr+2Mo+8Si+2Mn≦Ni+50N+6.4
and N≦0.40wt%, 0≦0.0060wt%P≦0.
040wt%, S≦0.005wt%, the balance being Fe and inevitable impurities, and highly corrosion-resistant austenitic stainless steel with excellent hot workability. 2, C≦0.030wt%, Si≦2.0wt%Mn≦
1.0wt%, Cr: 19-30wt% Ni: 20-3
0 wt%, Mo: 3.5 to 7.0 wt%, and B≦0.010 wt%, and a total of 2.0 wt% of at least one of W, V, or Cu.
% or less, Cr+3Mo+20N≧40 Cr+2Mo+8Si+2Mn≦Ni+50N+6.4
and N≦0.40wt%, 0≦0.0060wt%P≦0.
040wt%, S≦0.005wt%, the balance being Fe and inevitable impurities, and highly corrosion-resistant austenitic stainless steel with excellent hot workability. 3, C≦0.030wt%, Si≦2.0wt%Mn≦
1.0wt%, Cr: 19-30wt% Ni: 20-3
0 wt%, Mo: 3.5 to 7.0 wt%, and B≦0.010 wt%, Cr+3Mo+20N≧40 Cr+2Mo+8Si+2Mn≦Ni+50N+6.4
N≦0.40wt%, 0≦0.0060wt%P≦0.
040wt%, S≦0.005wt%, the balance being Fe and inevitable impurities, and highly corrosion-resistant austenitic stainless steel with excellent hot workability. 4, C≦0.030wt%, Si≦2.0wt%Mn≦
1.0wt%, Cr: 19-30wt% Ni: 20-3
0wt%, Mo: 3.5-7.0wt%B≦0.010
wt%, and Mg≦0.05wt%, and at least one of W, V, or Cu in a total of 2.0wt%.
% or less, Cr+3Mo+20N≧40 Cr+2Mo+8Si+2Mn≦Ni+50N+6.4
and N≦0.40wt%, 0≦0.0060wt%P≦0.
040wt%, S≦0.005wt%, the balance being Fe and inevitable impurities, and highly corrosion-resistant austenitic stainless steel with excellent hot workability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14028686A JPS62297443A (en) | 1986-06-18 | 1986-06-18 | Austenitic stainless steel having superior hot workability and high corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14028686A JPS62297443A (en) | 1986-06-18 | 1986-06-18 | Austenitic stainless steel having superior hot workability and high corrosion resistance |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6125176A Division JP2716937B2 (en) | 1994-06-07 | 1994-06-07 | High corrosion resistant austenitic stainless steel with excellent hot workability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62297443A true JPS62297443A (en) | 1987-12-24 |
| JPH0246662B2 JPH0246662B2 (en) | 1990-10-16 |
Family
ID=15265247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14028686A Granted JPS62297443A (en) | 1986-06-18 | 1986-06-18 | Austenitic stainless steel having superior hot workability and high corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62297443A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01259143A (en) * | 1988-04-11 | 1989-10-16 | Nippon Steel Corp | Cr-ni stainless steel hard to crack in casting stage or hot rolling stage thereafter |
| JPH04346638A (en) * | 1991-05-22 | 1992-12-02 | Nippon Yakin Kogyo Co Ltd | Sulfuric acid dew point corrosion resistant stainless steel excellent in hot workability |
| JPH06336652A (en) * | 1993-05-27 | 1994-12-06 | Agency Of Ind Science & Technol | Stainless forged steel for seawater pump of atomic power plant |
| JP2002069591A (en) * | 2000-09-01 | 2002-03-08 | Nkk Corp | High corrosion resistant stainless steel |
| WO2014087651A1 (en) * | 2012-12-05 | 2014-06-12 | Ｊｆｅスチール株式会社 | Stainless steel-clad steel plate having exceptional corrosion resistance to seawater |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4849731B2 (en) * | 2001-04-25 | 2012-01-11 | 日新製鋼株式会社 | Mo-containing high Cr high Ni austenitic stainless steel sheet excellent in ductility and manufacturing method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5120014A (en) * | 1974-08-08 | 1976-02-17 | Crucible Inc | |
| JPS5125422A (en) * | 1974-07-02 | 1976-03-02 | Westinghouse Electric Corp | |
| JPS54141310A (en) * | 1978-04-24 | 1979-11-02 | Kobe Steel Ltd | Austentic stainless steel with superior corrosion resistance and hot workability |
| JPS60211054A (en) * | 1984-04-03 | 1985-10-23 | Nippon Kokan Kk <Nkk> | Austenitic stainless steel having superior hot workability |
-
1986
- 1986-06-18 JP JP14028686A patent/JPS62297443A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5125422A (en) * | 1974-07-02 | 1976-03-02 | Westinghouse Electric Corp | |
| JPS5120014A (en) * | 1974-08-08 | 1976-02-17 | Crucible Inc | |
| JPS54141310A (en) * | 1978-04-24 | 1979-11-02 | Kobe Steel Ltd | Austentic stainless steel with superior corrosion resistance and hot workability |
| JPS60211054A (en) * | 1984-04-03 | 1985-10-23 | Nippon Kokan Kk <Nkk> | Austenitic stainless steel having superior hot workability |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01259143A (en) * | 1988-04-11 | 1989-10-16 | Nippon Steel Corp | Cr-ni stainless steel hard to crack in casting stage or hot rolling stage thereafter |
| JPH04346638A (en) * | 1991-05-22 | 1992-12-02 | Nippon Yakin Kogyo Co Ltd | Sulfuric acid dew point corrosion resistant stainless steel excellent in hot workability |
| JPH06336652A (en) * | 1993-05-27 | 1994-12-06 | Agency Of Ind Science & Technol | Stainless forged steel for seawater pump of atomic power plant |
| JP2002069591A (en) * | 2000-09-01 | 2002-03-08 | Nkk Corp | High corrosion resistant stainless steel |
| WO2014087651A1 (en) * | 2012-12-05 | 2014-06-12 | Ｊｆｅスチール株式会社 | Stainless steel-clad steel plate having exceptional corrosion resistance to seawater |
| EP2930254A4 (en) * | 2012-12-05 | 2015-12-30 | Jfe Steel Corp | Stainless steel-clad steel plate having exceptional corrosion resistance to seawater |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0246662B2 (en) | 1990-10-16 |
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