JP3747585B2 - High hardness martensitic stainless steel with excellent workability and corrosion resistance - Google Patents
High hardness martensitic stainless steel with excellent workability and corrosion resistance Download PDFInfo
- Publication number
- JP3747585B2 JP3747585B2 JP22861997A JP22861997A JP3747585B2 JP 3747585 B2 JP3747585 B2 JP 3747585B2 JP 22861997 A JP22861997 A JP 22861997A JP 22861997 A JP22861997 A JP 22861997A JP 3747585 B2 JP3747585 B2 JP 3747585B2
- Authority
- JP
- Japan
- Prior art keywords
- corrosion resistance
- less
- stainless steel
- hardness
- martensitic stainless
- 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 - Fee Related
Links
Landscapes
- Heat Treatment Of Steel (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、マルテンサイト系ステンレス鋼の改良に関し、加工性および耐食性に優れた高硬度マルテンサイト系ステンレス鋼を提供する。
【０００２】
【従来の技術】
各種の機械類の部品の中で、高い硬度を要求されるものの材料とするステンレス鋼としては、ＳＵＳ４２０Ｊ２やＳＵＳ４４０Ｃなどが代表的な材料として使用されて来た。 しかし、ＳＵＳ４２０Ｊ２は耐食性が高いとはいえない上に、焼入れ後の硬度が不十分であり、一方、ＳＵＳ４４０Ｃは焼入れ後の硬度は良好であるが、耐食性が劣る上、製造時に巨大な共晶炭化物が鋼中に残留しやすく、そのため熱間および冷間の加工性が劣るという問題があった。
【０００３】
【発明が解決しようとする課題】
本発明の目的は、ＪＩＳで規格化されているマルテンサイト系ステンレス鋼の中で最も高い硬度をもつ、ＳＵＳ４４０Ｃの硬さ規格ＨＲＣ≧５８を満たす硬さと、ＳＵＳ４２０Ｊ２の耐食性を超える耐食性とを有し、さらに熱間および冷間の加工性を向上させた、高硬度マルテンサイト系ステンレス鋼を提供することにある。
【０００４】
【課題を解決するための手段】
本発明の加工性および耐食性に優れた高硬度マルテンサイト系ステンレス鋼は、基本的な合金組成としては、重量％で、Ｃ：０．２０〜０．５０％、Ｓｉ：１．５％以下、Ｍｎ：２．０％以下、Ｃｕ：０．５〜２．０％、Ｃｒ：１０．０〜１５．０％およびＮ：０．０６〜０．２０％を含有し、Ｐ：０．０３％以下、Ｓ：０．００５０％以下、Ａｌ：０．０３０％以下、かつＯ：０．０１０％以下であって、残部が実質的にＦｅからなる合金組成を有する。
【０００５】
【発明の実施の形態】
本発明の高硬度マルテンサイト系ステンレス鋼は、上記の基本的な合金組成に加えて、下記のグループの成分を、少なくともひとつ含有することができる。
【０００６】
（１）Ｍｏ：０．１０〜１．０％およびＮｉ：０．１０〜１．０％の１種または２種、
（２）Ｂ：０．００１〜０．０１０％、Ｍｇ：０．００１〜０．０１０％およびＣａ：０．００１〜０．０１０％の１種または２種以上、
（３）Ｖ：０．０５〜０．５０％、Ｗ：０．０５〜０．５０％、Ｔｉ：０．０５〜０．５０％およびＮｂ：０．０５〜０．５０％の１種または２種以上、
（４）ＲＥＭ：０．０１０〜０．０５０。
【０００７】
本発明鋼における各合金成分の役割と組成範囲の限定理由を述べれば、つぎのとおりである。
【０００８】
Ｃ：０．２９〜０．５０％
Ｃは、マルテンサイト系ステンレス鋼の硬さを得るために最も重要な元素の一つである。０．２９％未満では、焼入れ焼戻し後の硬さが前記したＳＵＳ４４０Ｃの焼入れ焼戻し硬さ下限であるＨＲＣ５８を超える硬さを得ることができず、０．５０％を超える添加は、粗大な炭化物を生成させて、加工性および耐食性を低下させる。
【０００９】
Ｓｉ：１．５％以下
Ｓｉは脱酸剤であり、必要な限度で添加するが、靱性を低下させる成分であるから、その上限を１．５％とした。
【００１０】
Ｍｎ：２．０％以下
Ｍｎはオーステナイト生成元素であり、同時に、鋼中のＳを固定するはたらきをする。 多量の添加は、焼入れ時の残留オーステナイトを増加させ、硬度の低下を招く。 そこで、上限を２．０％とした。
【００１１】
Ｃｕ：０．５〜２．０％
Ｃｕもオーステナイト生成元素のひとつであり、耐食性および靱性の向上に寄与する。 とくに本発明においては、耐食性の向上への寄与が著しい。 ０．５％未満では効果が低く、２．０％を超える添加は、熱間加工性を劣化させるとともに、焼入れ時の残留オーステナイトを増加させ、やはり硬度を低下させる。 これらの兼ね合いで、上記の範囲０．５〜２．０％をえらんだ。
【００１２】
Ｃｒ：１０．０〜１５．０％
Ｃｒは、耐食性の確保に必須の元素であり、十分な耐食性をもたせるためには１０．０％以上の添加が必要であるが、１５．０％を超えるとＭ７Ｃ３型の粗大な炭化物が晶出し、加工性を下げる。この理由で、１０．０〜１５．０％の範囲を定めた。
【００１３】
Ｎ：０．０６〜０．２０％
Ｎは、強度の向上に大きく寄与し、Ｃを低減して炭化物の生成を抑えつつ硬度を高めることを可能にする結果、耐食性および加工性が向上する。 ０．０６％未満の添加ではその効果が小さく、０．２０％を超えて添加すると、凝固時に窒素ブローが発生して、製造が困難となる。 従って含有量の範囲を０．０６〜０．２０％とした。
【００１４】
本発明の鋼において不純物の含有量を規制する理由は、つぎのとおりである。
【００１５】
Ｐ：０．０３％以下
Ｐは、粒界腐食性を劣化させるので含有量は低い方が望ましいが、極度に低下させることは製造コストを上昇させる。 許容できる限度として、０．０３％を設けた。
【００１６】
Ｓ：０．００５０％以下
Ｓは、Ｍｎと化合物をつくり耐食性を劣化させるため、やはり含有量は低い方が望ましい。 しかしこれも、極度に低下させようとすると製造コストの上昇につながるので、許容限度０．００５０％を設けた。
【００１７】
Ａｌ：０．０３０％以下
Ａｌは脱酸剤として使用されるが、多量の添加は多量の酸化物が生成する結果を招き、冷間加工性を低くするので、その上限を０．０３０％とした。
【００１８】
Ｏ：０．０１０％以下
Ｏは金属元素と結合して介在物をつくり、冷間加工性を劣化させる。 許容限度が０．０１０％である。
【００１９】
任意に添加することのできる合金成分の作用と組成範囲の限定理由は、つぎのとおりである。
【００２０】
Ｍｏ：０．１０〜１．０％
Ｍｏは、マトリクスに固溶し、耐食性をいっそう向上させ、固溶強化により硬さを高める。 その効果は０．１０％未満では小さい。 １．０％を超えると、炭化物中にＭｏが含まれることにより炭化物が粗大化する。 結局、その範囲を０．１０〜１．０％とした。
【００２１】
Ｎｉ：０．１０〜１．０％
Ｎｉは、耐食性の向上に寄与し、他方で凝固時の窒素ブローを抑制する効果がある。 ０．１０％未満ではほとんど効果がなく、１．０％を超えると焼入れ硬さを低下させるので、その範囲を０．１０〜１．０％とした。
【００２２】
Ｂ：０.００１〜０.０１０、Ｍｇ:０.００１〜０.０１０％、Ｃａ:０．００１〜０．０１０％
Ｂ，ＭｇおよびＣａは、いずれも熱間加工性を向上させる元素である。 その効果は、０．００１％未満では小さく、０．０１０％を超えると、かえって熱間加工性を害するため、その範囲を０．００１〜０．０１０％とした。
【００２３】
Ｖ：０.０５〜０.５０、Ｗ：０．０５〜０．５０、Ｔｉ：０．０５〜０．５０、Ｎｂ：０．０５〜０．５０
Ｖ，Ｗ，ＴｉおよびＮｂは、安定化した微細な炭化物を形成し、それによって結晶粒を微細化して、強度、靱性等の機械的性質を向上させる。 ０．０５％未満ではほとんど効果がなく、０．５０％を超えると、加工性および靱性が低下する。
【００２４】
ＲＥＭ：０．０１０〜０．０５０
ＲＥＭは、鋼の脱硫、脱酸に有効な元素であり、また熱間加工性を改善する目的で添加してもよい。 ０．０１０％未満では効果が乏しく、０．０５０％を超えると、逆に熱間加工性を害する。
【００２５】
【実施例】
本発明を具体的に説明するため、以下にその実施例を示す。 表１Ａおよび表１Ｂに示す化学成分（重量％、残部Ｆｅ）の鋼を高周波誘導炉で溶製し、５０kg鋼塊に鋳造した。
【００２６】
【表１Ａ】
【００２７】
グリーブル試験は、Ｍ６×１１０mmの試験片を、１００sec.の間に所望の温度に加熱し、その温度に６０sec.保持した後に、２in／sec.の速度で引っ張ることにより行なった。 そのときの絞り値が６０％以上である温度範囲がどうであるかによって、熱間加工性を評価した。 評価は、つぎの四段階とした：
Ａ：３００℃以上、
Ｂ：２５０℃〜３００℃、
Ｃ：２００℃〜２５０℃、および
Ｄ：２００℃以下。
【００２８】
限界割れ試験は、径１５mm×高さ２２．５mmの試験片を使用して、端面拘束圧縮試験を行なって、５０％に割れが発生する限界の圧縮率を求めた。
【００２９】
湿潤試験は、径１５mm×高さ１１５mmの試験片を使用して、５０℃×９５％ＲＨ雰囲気中で９６Hr保持した後の、腐食の有無を確認することにより行なった。試験後の評価は、つぎの四段階とした：
Ａ：腐食せず、
Ｂ：若干の腐食あり、
Ｃ：腐食あり、および
Ｄ：全面腐食。
【００３０】
上記の各試験の結果を、表２Ａおよび表２Ｂに示す。
【００３１】
表２Ａ 実施例
比較例１は、ＣとＮの添加量が少ないため、硬さの要求を満足しない。 比較例２は、Ｃの添加量が多すぎるため、熱間および冷間の加工性と、耐食性において劣る。 比較例３は、Ｃｕを添加しないため耐食性が劣る。 その他の比較例についても、熱間加工性、硬さ、耐食性のいずれかに問題があることが、表２Ａおよび２Ｂのデータからわかる。
【００３３】
【発明の効果】
本発明により、加工性および耐食性に優れた高硬度マルテンサイト系ステンレス鋼が提供される。 この材料を使用することにより、各種機械類の部品（たとえば、軸受け、シャフト等）において、高硬度と耐食性の要求を、同時に満たすことができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of martensitic stainless steel, and provides a high-hardness martensitic stainless steel excellent in workability and corrosion resistance.
[0002]
[Prior art]
SUS420J2 and SUS440C have been used as typical materials for stainless steels that are required to have high hardness among various machine parts. However, SUS420J2 cannot be said to have high corrosion resistance and has insufficient hardness after quenching, whereas SUS440C has good hardness after quenching, but has poor corrosion resistance and a large eutectic carbide during production. However, there is a problem that hot and cold workability is inferior.
[0003]
[Problems to be solved by the invention]
The object of the present invention is to have the hardness which satisfies the hardness standard HRC ≧ 58 of SUS440C, which has the highest hardness among martensitic stainless steels standardized by JIS, and the corrosion resistance which exceeds the corrosion resistance of SUS420J2. Another object of the present invention is to provide a high-hardness martensitic stainless steel with improved hot and cold workability.
[0004]
[Means for Solving the Problems]
The high-hardness martensitic stainless steel excellent in workability and corrosion resistance according to the present invention has, as a basic alloy composition, wt%, C: 0.20 to 0.50%, Si: 1.5% or less, Mn: 2.0% or less, Cu: 0.5-2.0%, Cr: 10.0-15.0% and N: 0.06-0.20%, P: 0.03% Hereinafter, S: 0.0050% or less, Al: 0.030% or less, and O: 0.010% or less, with the balance being substantially composed of Fe.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The high-hardness martensitic stainless steel of the present invention can contain at least one of the following groups of components in addition to the above basic alloy composition.
[0006]
(1) One or two of Mo: 0.10 to 1.0% and Ni: 0.10 to 1.0%,
(2) B: 0.001 to 0.010%, Mg: 0.001 to 0.010%, and Ca: 0.001 to 0.010%, one or more,
(3) One of V: 0.05 to 0.50%, W: 0.05 to 0.50%, Ti: 0.05 to 0.50% and Nb: 0.05 to 0.50% or 2 or more types,
(4) REM: 0.010 to 0.050.
[0007]
The role of each alloy component in the steel of the present invention and the reason for limiting the composition range are described as follows.
[0008]
C: 0.29 to 0.50%
C is one of the most important elements for obtaining the hardness of martensitic stainless steel. If it is less than 0.29%, the hardness after quenching and tempering cannot obtain a hardness exceeding HRC58 which is the lower limit of quenching and tempering hardness of SUS440C described above, and addition exceeding 0.50% results in coarse carbides. To reduce workability and corrosion resistance.
[0009]
Si: 1.5% or less Si is a deoxidizer and is added to the necessary limit. However, since it is a component that lowers toughness, the upper limit was made 1.5%.
[0010]
Mn: 2.0% or less Mn is an austenite-forming element and simultaneously serves to fix S in steel. A large amount of addition increases the retained austenite at the time of quenching and causes a decrease in hardness. Therefore, the upper limit was made 2.0%.
[0011]
Cu: 0.5 to 2.0%
Cu is also an austenite-generating element and contributes to the improvement of corrosion resistance and toughness. Particularly in the present invention, the contribution to the improvement of corrosion resistance is remarkable. If it is less than 0.5%, the effect is low, and if it exceeds 2.0%, the hot workability is deteriorated, the retained austenite at the time of quenching is increased, and the hardness is also lowered. In view of these factors, the above range of 0.5 to 2.0% was selected.
[0012]
Cr: 10.0-15.0%
Cr is an essential element for ensuring corrosion resistance, and in order to have sufficient corrosion resistance, addition of 10.0% or more is necessary, but if it exceeds 15.0%, coarse carbide of M 7 C 3 type Crystallizes and decreases workability. For this reason, a range of 10.0 to 15.0% is determined.
[0013]
N: 0.06-0.20%
N greatly contributes to the improvement of strength, and as a result of reducing C and suppressing the formation of carbides while increasing the hardness, corrosion resistance and workability are improved. If the addition is less than 0.06%, the effect is small. If the addition exceeds 0.20%, nitrogen blow occurs during solidification, which makes production difficult. Therefore, the content range is set to 0.06 to 0.20%.
[0014]
The reason for regulating the content of impurities in the steel of the present invention is as follows.
[0015]
P: 0.03% or less P has a lower content because it degrades intergranular corrosion. However, extremely lowering the production cost increases. As an acceptable limit, 0.03% was set.
[0016]
S: 0.0050% or less Since S forms a compound with Mn and degrades the corrosion resistance, the lower content is desirable. However, since this also leads to an increase in manufacturing cost if an attempt is made to reduce it extremely, an allowable limit of 0.0050% is set.
[0017]
Al: 0.030% or less Al is used as a deoxidizing agent. However, addition of a large amount leads to the formation of a large amount of oxides and lowers the cold workability, so the upper limit is 0.030%. did.
[0018]
O: 0.010% or less O is combined with a metal element to form inclusions and deteriorate cold workability. The allowable limit is 0.010%.
[0019]
The reasons for limiting the action and composition range of the alloy components that can be optionally added are as follows.
[0020]
Mo: 0.10 to 1.0%
Mo dissolves in the matrix, further improves the corrosion resistance, and increases the hardness by solid solution strengthening. The effect is small at less than 0.10%. If it exceeds 1.0%, the carbide is coarsened due to the inclusion of Mo in the carbide. Eventually, the range was made 0.10 to 1.0%.
[0021]
Ni: 0.10 to 1.0%
Ni contributes to the improvement of corrosion resistance and, on the other hand, has an effect of suppressing nitrogen blow during solidification. If it is less than 0.10%, there is almost no effect, and if it exceeds 1.0%, the quenching hardness is reduced, so the range was made 0.10 to 1.0%.
[0022]
B: 0.001 to 0.010, Mg: 0.001 to 0.010%, Ca: 0.001 to 0.010%
B, Mg and Ca are all elements that improve hot workability. The effect is small if it is less than 0.001%, and if it exceeds 0.010%, the hot workability is adversely affected. Therefore, the range is made 0.001 to 0.010%.
[0023]
V: 0.05-0.50, W: 0.05-0.50, Ti: 0.05-0.50, Nb: 0.05-0.50
V, W, Ti, and Nb form stabilized fine carbides, thereby refining crystal grains and improving mechanical properties such as strength and toughness. If it is less than 0.05%, there is almost no effect, and if it exceeds 0.50%, workability and toughness deteriorate.
[0024]
REM: 0.010 to 0.050
REM is an element effective for desulfurization and deoxidation of steel, and may be added for the purpose of improving hot workability. If it is less than 0.010%, the effect is poor, and if it exceeds 0.050%, hot workability is adversely affected.
[0025]
【Example】
In order to describe the present invention specifically, examples thereof are shown below. Steels having the chemical components shown in Tables 1A and 1B (wt%, balance Fe) were melted in a high frequency induction furnace and cast into a 50 kg steel ingot.
[0026]
[Table 1A]
[0027]
The greeble test was performed by heating a test piece of M6 × 110 mm to a desired temperature for 100 sec., Holding at that temperature for 60 sec., And then pulling at a speed of 2 in / sec. The hot workability was evaluated depending on the temperature range in which the aperture value at that time was 60% or more. The evaluation was divided into the following four stages:
A: 300 ° C. or higher,
B: 250 ° C to 300 ° C,
C: 200 ° C. to 250 ° C., and D: 200 ° C. or less.
[0028]
In the limit cracking test, an end face constrained compression test was performed using a test piece having a diameter of 15 mm and a height of 22.5 mm, and the compression ratio at which cracking occurred at 50% was determined.
[0029]
The wetting test was performed by using a test piece having a diameter of 15 mm and a height of 115 mm and confirming the presence or absence of corrosion after being held for 96 hours in a 50 ° C. × 95% RH atmosphere. The post-test evaluation was divided into the following four stages:
A: No corrosion,
B: There is some corrosion,
C: Corrosion, and D: Overall corrosion.
[0030]
The results of the above tests are shown in Table 2A and Table 2B.
[0031]
Table 2A Examples
Since the comparative example 1 has few addition amounts of C and N, it does not satisfy the hardness requirement. Comparative Example 2 is inferior in hot and cold workability and corrosion resistance because the amount of C added is too large. Since the comparative example 3 does not add Cu, corrosion resistance is inferior. It can be seen from the data in Tables 2A and 2B that other comparative examples also have problems in any of hot workability, hardness, and corrosion resistance.
[0033]
【The invention's effect】
The present invention provides a high-hardness martensitic stainless steel excellent in workability and corrosion resistance. By using this material, it is possible to satisfy the requirements of high hardness and corrosion resistance at the same time in parts of various machines (for example, bearings, shafts, etc.).
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22861997A JP3747585B2 (en) | 1997-08-25 | 1997-08-25 | High hardness martensitic stainless steel with excellent workability and corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22861997A JP3747585B2 (en) | 1997-08-25 | 1997-08-25 | High hardness martensitic stainless steel with excellent workability and corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1161351A JPH1161351A (en) | 1999-03-05 |
| JP3747585B2 true JP3747585B2 (en) | 2006-02-22 |
Family
ID=16879190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22861997A Expired - Fee Related JP3747585B2 (en) | 1997-08-25 | 1997-08-25 | High hardness martensitic stainless steel with excellent workability and corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3747585B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000329042A (en) * | 1999-05-20 | 2000-11-28 | Mitsubishi Electric Corp | Starter |
| SE522352C2 (en) * | 2000-02-16 | 2004-02-03 | Sandvik Ab | Elongated element for striking rock drilling and use of steel for this |
| KR20010097129A (en) * | 2000-04-20 | 2001-11-08 | 이구택 | Nitrogen bearing martensitic stainless steel |
| FR2896514B1 (en) * | 2006-01-26 | 2008-05-30 | Aubert & Duval Soc Par Actions | STAINLESS STEEL MARTENSITIC STEEL AND METHOD FOR MANUFACTURING A WORKPIECE IN THIS STEEL, SUCH AS A VALVE. |
| KR101239589B1 (en) | 2010-12-27 | 2013-03-05 | 주식회사 포스코 | High corrosion resistance martensite stainless steel and method of manufacturing the same |
| DE102013220840B4 (en) * | 2013-10-15 | 2017-08-03 | Schaeffler Technologies AG & Co. KG | Bearing element for a rolling or sliding bearing |
| CN103667960B (en) * | 2013-11-08 | 2016-04-20 | 铜陵安东铸钢有限责任公司 | Carbon stainless steel material and preparation method thereof in one |
| JP2017150045A (en) * | 2016-02-26 | 2017-08-31 | 山陽特殊製鋼株式会社 | Martensitic stainless steel |
| CN109750222B (en) * | 2017-12-08 | 2020-12-15 | 上海落日新材料科技有限公司 | High-performance martensitic stainless steel and manufacturing method of high-flatness plate thereof |
| KR20220016835A (en) * | 2019-06-05 | 2022-02-10 | 에이비 산드빅 매터리얼즈 테크놀로지 | Martensitic stainless steel alloy |
| CN112048677A (en) * | 2020-08-28 | 2020-12-08 | 阳江十八子刀剪制品有限公司 | Martensite stainless steel for cutter and preparation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56158847A (en) * | 1980-05-09 | 1981-12-07 | Hitachi Ltd | Heat resistant chromium steel |
| JPH07278758A (en) * | 1994-04-13 | 1995-10-24 | Nippon Steel Corp | Stainless steel for engine gasket and its production |
| JP2968844B2 (en) * | 1995-01-13 | 1999-11-02 | 日立金属株式会社 | High hardness martensitic stainless steel with excellent pitting resistance |
| JPH11303874A (en) * | 1997-04-16 | 1999-11-02 | Nippon Seiko Kk | Rolling member |
-
1997
- 1997-08-25 JP JP22861997A patent/JP3747585B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1161351A (en) | 1999-03-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1873270B1 (en) | Low alloy steel | |
| JP3763573B2 (en) | Spring steel with improved hardenability and pitting corrosion resistance | |
| JP2001355048A (en) | Ferritic free-cutting stainless steel | |
| JP4816642B2 (en) | Low alloy steel | |
| JP3747585B2 (en) | High hardness martensitic stainless steel with excellent workability and corrosion resistance | |
| CN109790602B (en) | Steel | |
| JP2834654B2 (en) | High toughness hot work tool steel | |
| JP4396561B2 (en) | Induction hardening steel | |
| JPS5946300B2 (en) | Steel for cold forging with excellent machinability and its manufacturing method | |
| JP2000328198A (en) | Austenitic stainless steel excellent in hot workability | |
| JP7149250B2 (en) | Hot work tool steel with excellent high temperature strength and toughness | |
| JP5245544B2 (en) | Common rail with excellent fatigue characteristics | |
| JP4108493B2 (en) | Austenitic S free-cutting stainless steel | |
| JP2022143564A (en) | Hot work tool steel having excellent softening resistance and quenchability | |
| JP3494271B2 (en) | Free-cutting non-heat treated steel with excellent strength and toughness | |
| JP3249646B2 (en) | Machine structural steel with excellent machinability and cold forgeability | |
| JP2006089784A (en) | Bn-containing free cutting steel | |
| JPH0820841A (en) | Rolling member | |
| JP4515347B2 (en) | Method for determining fatigue resistance of spring steel wires and spring steel wires | |
| JP3460721B2 (en) | Machine structural steel | |
| JP3662151B2 (en) | Heat-resistant cast steel and heat treatment method thereof | |
| JP2733989B2 (en) | Free cutting steel with excellent hot ductility | |
| JP2018028149A (en) | Case hardened steel | |
| JP7141944B2 (en) | Non-tempered forged parts and steel for non-tempered forgings | |
| JP3299034B2 (en) | Machine structural steel with excellent cold forgeability, machinability, mechanical properties after quenching and tempering, and fatigue strength properties |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040625 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20050414 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050426 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050624 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20051108 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20051121 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081209 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091209 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091209 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101209 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101209 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111209 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111209 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121209 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121209 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131209 Year of fee payment: 8 |
|
| LAPS | Cancellation because of no payment of annual fees |