JPS629182B2 - - Google Patents
Info
- Publication number
- JPS629182B2 JPS629182B2 JP58005254A JP525483A JPS629182B2 JP S629182 B2 JPS629182 B2 JP S629182B2 JP 58005254 A JP58005254 A JP 58005254A JP 525483 A JP525483 A JP 525483A JP S629182 B2 JPS629182 B2 JP S629182B2
- Authority
- JP
- Japan
- Prior art keywords
- steel
- corrosion resistance
- present
- stainless steel
- strength
- 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
- 230000007797 corrosion Effects 0.000 claims description 31
- 238000005260 corrosion Methods 0.000 claims description 31
- 229910001208 Crucible steel Inorganic materials 0.000 claims description 12
- 229910001105 martensitic stainless steel Inorganic materials 0.000 claims description 7
- 229910052750 molybdenum Inorganic materials 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 description 19
- 239000010959 steel Substances 0.000 description 19
- 230000000052 comparative effect Effects 0.000 description 12
- 239000011651 chromium Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 239000002436 steel type Substances 0.000 description 6
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- 239000010935 stainless steel Substances 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910000734 martensite Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- 238000010612 desalination reaction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009661 fatigue test Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Landscapes
- Rolling Contact Bearings (AREA)
- Heat Treatment Of Steel (AREA)
Description
本発明は優れた耐食性と、腐食疲労強度とを兼
ね備えたマルテンサイト系ステンレス鋳鋼に関す
る。
腐食環境の厳しい河川用水車ランナー、化学プ
ラント、食品工業機械、製紙機械、淡水化装置等
においては優れた耐食性と腐食疲労強度とを共に
備えたステンレス鋳鋼が要求される。
従来、例えば、水車ランナー材には主として13
％Cr―Ni系マルテンサイトステンレス鋳鋼が使
用されていたが、この種ステンレス鋳鋼は、強
度、靭性および耐キヤビテーシヨン性は優れてい
るもののクロム含有量が低いためオーステナイト
系ステンレス鋼に比較して耐食性は充分とは云え
なかつた。
すなわち、腐食環境の厳しい条件で使用される
水車ランナー、淡水化装置、海洋構造物等におい
ては、高い腐食疲労強度を有する材料が絶対必要
条件であるが、上記の従来より使用されている13
％Cr―Ni系鋳鋼では耐食性および腐食疲労強度
が不十分であるため、より優れた耐食性と腐食疲
労強度とを兼ね備えたステンレス鋳鋼の開発が要
望されていた。
本発明は、上記に鑑みなされたもので、マルテ
ンサイト系ステンレス鋳鋼の優れた機械的性質す
なわち、高強度、高靭性を有し、しかも耐食性、
特に腐食疲労強度を大巾に改善したマルテンサイ
ト系ステンレス鋳鋼を提供することを目的とす
る。
この目的は、重量基準でC0.10％以下、Si1.00
％以下、Mn0.50―1.00％、Ni4.00―6.00％、
Cr16.00―18.00％、Mo0.50―1.50％を含みFeお
よび不可避不純物からなるマルテンサイト系ステ
ンレス鋳鋼により達成される。
本発明についてさらに詳細に説明する。
本発明のマルテンサイト系ステンレス鋳鋼は合
金成分として、上記のように、重量基準でC0.10
％以下、Si1.00％以下、Mn0.50―1.00％、Ni5.00
―6.00％、Cr16.00―18.00％、Mo0.50―1.50％を
含有するが、このように成分元素含有量を限定し
た理由について説明する。
Ｃはマルテンサイトの強度を向上させる作用を
有するが、これの過剰な添加は靭性および耐食性
を著しく低下させるので、その上限を0.1％とし
た。
SiおよびMnは、本発明鋼においても通常のマ
ルテンサイト系ステンレス鋼の組成範囲、すなわ
ちSi1.00％以下、Mn0.50―1.00％であつて、この
範囲において大気溶解にて工業的に容易に本発明
鋼は製造され得るものである。
NiはCrとの複合効果で耐食性を向上させると
ともに強度おび靭性の改善にも極めて有効な元素
であり、ステンレス鋼をマルテンサイト化するた
めには4.00―5.00％が適当である。
Crはステンレス鋼には重要な元素で耐食性を
向上させる作用を有するものであるが、耐食性を
著しく向上させるためには16.00％以上含有させ
る必要があり、一方18.00％をこえるとフエライ
ト相が増加し靭性を損なうので、その範囲を
16.00―18.00％に限定した。
Moは耐局部耐食性を著しく向上させる元素で
あるが、0.50％未満ではその効果は不充分であ
り、一方1.50％をこえると添加効果が飽和し、し
かもフエライト相を増加して靭性の低下を招くこ
とになるので、その範囲を0.50―1.50％に限定し
た。
なお、上記の成分範囲の限定理由は各成分元素
個々の効果について説明したが、本発明の効果
は、上記以外に、これら成分の相互作用ないし相
乗作用によりもたらされるものである。
つぎに本発明の特徴について、実施例に基づ
き、比較例との対比により詳述する。
第１表に本発明鋼の４の実施例および比較鋼
（６種類）の化学組成を示す。
The present invention relates to a martensitic stainless cast steel that has both excellent corrosion resistance and corrosion fatigue strength. Stainless steel cast steel with both excellent corrosion resistance and corrosion fatigue strength is required for river water turbine runners, chemical plants, food industry machinery, paper manufacturing machinery, desalination equipment, etc., which are exposed to harsh corrosive environments. Conventionally, for example, water turbine runner materials mainly used 13
%Cr-Ni martensitic stainless steel cast steel has been used, but although this type of stainless steel cast steel has excellent strength, toughness, and cavitation resistance, it has low chromium content and therefore has poor corrosion resistance compared to austenitic stainless steel. I couldn't say it was enough. In other words, materials with high corrosion fatigue strength are an absolute requirement for water turbine runners, desalination equipment, marine structures, etc. that are used in severe corrosive environments, but the materials that have been used conventionally as described above13
Since %Cr-Ni cast steel has insufficient corrosion resistance and corrosion fatigue strength, there has been a demand for the development of stainless steel cast steel that has both superior corrosion resistance and corrosion fatigue strength. The present invention has been made in view of the above, and has the excellent mechanical properties of martensitic stainless steel cast steel, that is, high strength and high toughness, as well as corrosion resistance and
In particular, the object is to provide a martensitic stainless steel cast steel with greatly improved corrosion fatigue strength. The purpose is to achieve C0.10% or less and Si1.00% by weight.
% or less, Mn0.50-1.00%, Ni4.00-6.00%,
This is achieved using martensitic stainless steel cast steel containing 16.00-18.00% Cr, 0.50-1.50% Mo, Fe, and inevitable impurities. The present invention will be explained in more detail. The martensitic stainless steel cast steel of the present invention has an alloy component of C0.10 on a weight basis, as mentioned above.
% or less, Si1.00% or less, Mn0.50-1.00%, Ni5.00
-6.00%, Cr16.00-18.00%, and Mo0.50-1.50%.The reason for limiting the component element content in this way will be explained. Although C has the effect of improving the strength of martensite, excessive addition of C significantly reduces toughness and corrosion resistance, so the upper limit was set at 0.1%. In the steel of the present invention, Si and Mn are in the composition range of normal martensitic stainless steel, that is, Si is 1.00% or less and Mn is 0.50-1.00%, and in this range, they can be easily dissolved industrially in the atmosphere. The steel of the present invention can be produced. Ni is an element that is extremely effective in improving corrosion resistance as well as strength and toughness due to its combined effect with Cr, and 4.00-5.00% is appropriate for converting stainless steel into martensite. Cr is an important element in stainless steel and has the effect of improving corrosion resistance, but in order to significantly improve corrosion resistance, it must be contained at 16.00% or more, while if it exceeds 18.00%, the ferrite phase increases. It will damage the toughness, so please limit the range.
Limited to 16.00-18.00%. Mo is an element that significantly improves local corrosion resistance, but if it is less than 0.50%, the effect is insufficient, while if it exceeds 1.50%, the added effect is saturated, and moreover, it increases the ferrite phase and causes a decrease in toughness. Therefore, we limited the range to 0.50-1.50%. Although the reasons for limiting the above component ranges have been explained with respect to the individual effects of each component element, the effects of the present invention are brought about by the interaction or synergistic effect of these components in addition to the above. Next, the features of the present invention will be explained in detail based on Examples and in comparison with Comparative Examples. Table 1 shows the chemical compositions of four examples of the steel of the present invention and comparative steels (six types).
【表】
つぎに第１表に示す各鋼種の機械的性質を第２
表、塩水中におけるアノード分極測定結果を第１
図、腐食疲労試験結果（Ｓ―Ｎ曲線）を第２図に
それぞれ示す。[Table] Next, the mechanical properties of each steel type shown in Table 1 are
Table 1 shows the results of anode polarization measurements in salt water.
Figure 2 shows the corrosion fatigue test results (SN curve).
【表】【table】
【表】
第１表および第２表より見てCr、Moが本発明
鋼より低く、耐食性の劣る比較鋼５，６では強度
が低いことと相まつて、腐食切欠き疲れ強さ（σ
wbkc）が低い。また、比較鋼７〜10はCr，Moが
高く良好な耐食性を有するからσwbkcは改善さ
れているが、本発明鋼に及ばない。これは強度が
低いためである。比較鋼１０はMoが本発明鋼以
上に含有し、良好な耐食性と高い強度を有するこ
とから、σwbkcは高い。しかしながらMo量が高
いため、デルタフエライトが増加するので、伸
び、絞り、衝撃値が低い。
他方、本発明鋼である１〜４は良好な耐食性を
有し、かつ強度レベルが高いため、いずれも高い
σwbkcを有する。また、伸び、絞り、衝撃値の
劣化もほとんどない。
耐腐食性に関しては、第１図に示すアノード分
極曲線でみると、アノードピーク電流および不働
態化保持電流がCr量の増加と共に低下してお
り、本発明鋼が他の比較鋼種（13Cr―4Ni―
Mo，16.5Cr―4.5Ni）より耐食性が極めて優れて
いることが明らかである。この事より、上記比較
鋼種と類似の13Cr―3.8Ni鋳鋼に比べ本発明鋼が
極めて優れた耐食性を有することは明らかであ
る。
さらに、第２図に示す腐食疲労強度（Ｓ―Ｎ曲
線）についてみると、本発明鋼は他の比較鋼種
（18―8Mo，13Cr―1Ni―1Mo，13Cr―4Ni，18―
８）より極めて優れた疲労寿命を有することが明
らかであり、勿論これら比較鋼種と類似の第１表
に示す各比較鋼種よりも優れていることは明らか
である。
以上説明したように、本発明鋼は、優れた機械
的性質を有すると共に耐食性および腐食疲労強度
が著るしく優れ、厳しい腐食環境下における使用
に適していることが明らかである。[Table] As seen from Tables 1 and 2, Cr and Mo are lower than that of the present invention steel, and Comparative Steels 5 and 6, which have inferior corrosion resistance, have low strength, and the corrosion notch fatigue strength (σ
wbkc) is low. Further, Comparative Steels 7 to 10 have high Cr and Mo content and have good corrosion resistance, so that σwbkc is improved, but it is not as good as the steel of the present invention. This is because the strength is low. Comparative Steel 10 contains more Mo than the steel of the present invention and has good corrosion resistance and high strength, so σwbkc is high. However, due to the high Mo content, delta ferrite increases, resulting in low elongation, narrowing, and impact values. On the other hand, steels 1 to 4 of the present invention have good corrosion resistance and a high strength level, so all have high σwbkc. Additionally, there is almost no deterioration in elongation, aperture, or impact value. Regarding corrosion resistance, the anode polarization curve shown in Figure 1 shows that the anode peak current and passivation holding current decrease with increasing Cr content, indicating that the steel of the present invention is superior to other comparative steel types (13Cr-4Ni). ―
It is clear that the corrosion resistance is extremely superior to that of Mo, 16.5Cr-4.5Ni). From this, it is clear that the steel of the present invention has extremely superior corrosion resistance compared to 13Cr-3.8Ni cast steel, which is similar to the comparative steel type mentioned above. Furthermore, looking at the corrosion fatigue strength (SN curve) shown in Fig. 2, the steel of the present invention was compared to other comparative steel types (18-8Mo, 13Cr-1Ni-1Mo, 13Cr-4Ni, 18-
8) It is clear that it has an extremely superior fatigue life, and of course it is clearly superior to each of the comparative steel types shown in Table 1 that are similar to these comparative steel types. As explained above, it is clear that the steel of the present invention has excellent mechanical properties and significantly excellent corrosion resistance and corrosion fatigue strength, and is suitable for use in a severe corrosive environment.
第１図は本発明鋼と比較鋼のアノード分極曲線
図、第２図は本発明鋼と比較鋼の腐食疲労強度：
Ｓ―Ｎ曲線図である。
Figure 1 shows the anode polarization curves of the inventive steel and comparative steel, and Figure 2 shows the corrosion fatigue strength of the inventive steel and comparative steel:
It is an SN curve diagram.
Claims (1)
Mn0.50―1.00％、Ni4.00―6.00％、Cr16.00―
18.00％、Mo0.50―1.50％を含み残部がFeおよび
不可避不純物から成ることを特徴とするマルテン
サイト系の高腐食疲労強度を有するステンレス鋳
鋼。1 C0.10% or less, Si1.00% or less on a weight basis,
Mn0.50―1.00%, Ni4.00―6.00%, Cr16.00―
Martensitic stainless steel cast steel with high corrosion fatigue strength, containing 18.00% Mo, 0.50-1.50% Mo, and the balance consisting of Fe and inevitable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP525483A JPS59129755A (en) | 1983-01-18 | 1983-01-18 | Stainless steel cast with high corrosion fatigue strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP525483A JPS59129755A (en) | 1983-01-18 | 1983-01-18 | Stainless steel cast with high corrosion fatigue strength |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59129755A JPS59129755A (en) | 1984-07-26 |
| JPS629182B2 true JPS629182B2 (en) | 1987-02-26 |
Family
ID=11606079
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP525483A Granted JPS59129755A (en) | 1983-01-18 | 1983-01-18 | Stainless steel cast with high corrosion fatigue strength |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59129755A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63171857A (en) * | 1987-01-10 | 1988-07-15 | Nippon Yakin Kogyo Co Ltd | Manufacture of precipitation hardening-type stainless steel excellent in fatigue characteristic |
| JP2622389B2 (en) * | 1987-12-08 | 1997-06-18 | 株式会社 クボタ | Martensitic stainless steel with high corrosion fatigue strength and excellent corrosion resistance |
| JPH01152243A (en) * | 1987-12-08 | 1989-06-14 | Kubota Ltd | Martensitic stainless steel having high corrosion fatigue strength and excellent corrosion resistance |
| JP2647906B2 (en) * | 1988-06-13 | 1997-08-27 | 株式会社クボタ | Martensitic stainless steel with excellent corrosion resistance |
-
1983
- 1983-01-18 JP JP525483A patent/JPS59129755A/en active Granted
Non-Patent Citations (1)
| Title |
|---|
| SULZER TECHNICAL REVIEW=1980 * |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59129755A (en) | 1984-07-26 |
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