JPS62199751A - Steel for header - Google Patents
Steel for headerInfo
- Publication number
- JPS62199751A JPS62199751A JP3937486A JP3937486A JPS62199751A JP S62199751 A JPS62199751 A JP S62199751A JP 3937486 A JP3937486 A JP 3937486A JP 3937486 A JP3937486 A JP 3937486A JP S62199751 A JPS62199751 A JP S62199751A
- Authority
- JP
- Japan
- Prior art keywords
- header
- delayed fracture
- steel
- strength
- fracture resistance
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 19
- 239000010959 steel Substances 0.000 title claims abstract description 19
- 230000003111 delayed effect Effects 0.000 claims abstract description 26
- 239000012535 impurity Substances 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 7
- 229910052796 boron Inorganic materials 0.000 claims abstract description 6
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 abstract description 5
- 230000001105 regulatory effect Effects 0.000 abstract description 4
- 229910052804 chromium Inorganic materials 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 238000000137 annealing Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000010791 quenching Methods 0.000 description 4
- 230000000171 quenching effect Effects 0.000 description 4
- 238000005496 tempering Methods 0.000 description 4
- 238000005452 bending Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000012669 compression test Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は主にボルト類に用いられるヘッダー用鋼に関す
る。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to header steel mainly used for bolts.
（従来の技術及び問題点）
最近、切削加工や熱間鋳造に代わり、冷間鋳造によって
製造される機械構造部品が増加してきている。特にボル
ト類は従来より冷間ヘッダーによって加工されているが
、加工の高速化や過酷化（加工率の増大）に伴ってヘッ
ダー性の優れた線材が要求されるようになった。ヘッダ
ー性としては、変形抵抗が小さく変形能が大きいことが
必要とされるが、かへるヘッダー用線材は、ボルト類に
用いられるのが殆どであり、当然のことながら使用時に
要求される諸特性も満足することが重要である。特に引
張強・さが１１０ ｋｇ ｆ ／ｍｍ”以上の高強度域
で使用される場合には、遅れ破壊に敏感になることから
、耐遅れ破壊性に対して十分な配慮を払う必要がある。(Prior Art and Problems) Recently, an increasing number of mechanical structural parts are manufactured by cold casting instead of cutting or hot casting. In particular, bolts have traditionally been processed using cold headers, but as processing becomes faster and more severe (increasing processing rates), wire rods with excellent header properties are required. Header properties require low deformation resistance and high deformability, but since wire rods for headers are mostly used for bolts, they naturally meet the various requirements during use. It is important that the characteristics are also satisfied. In particular, when used in a high-strength region with a tensile strength of 110 kg f /mm'' or higher, sufficient consideration must be given to delayed fracture resistance since the material is sensitive to delayed fracture.
この点、従来のへラダー用材料はへラダー性はもとより
特に耐遅れ破壊性が必ずしも十分でなく、高強度域での
使用に問題があった。In this regard, conventional materials for ladders do not necessarily have sufficient laddering properties and especially delayed fracture resistance, and have had problems in use in high-strength regions.
（発明の目的）
本発明は、上記従来技術の欠点を解消し、ヘッダー性及
び耐遅れ破壊性に優れたヘッダー用鋼を提供することを
目的とするものである。(Objective of the Invention) An object of the present invention is to eliminate the drawbacks of the above-mentioned prior art and provide a steel for a header that has excellent header properties and delayed fracture resistance.
（発明の構成）
上記目的を達成するため、本発明は、ヘッダー性、耐遅
れ破壊性に及ぼす合金元素の影響を種々検討し、各合金
元素を特定の範囲に規制することにより可能としたもの
である。(Structure of the Invention) In order to achieve the above object, the present invention was made possible by various studies on the effects of alloying elements on header properties and delayed fracture resistance, and by regulating each alloying element within a specific range. It is.
すなわち、本発明は、Ｃ： ０．２０−０．５０％を含
み、Ｓｉ≦０．１０％、ＭｎＳ１．６０％、Ｐ≦０．０
１５％、Ｓ≦０．００５％に規制し、更にＣｒ： ０．
０１〜２０％及びＡｌ：０．００５〜０．０ ！５０％
を添加し、必要に応じてＮｉ二０．１〜２０％、Ｍｏ：
０．１−１，０％、Ｖ ： ０．０１〜０．５０％及び
Ｂ ： ０．０００５〜０．００５０％のうちの１種又
２種以上を添加し、残部がＦｅ及び不可避的不純物から
なる成分組成とすることを特徴とし、優れたヘッダー性
及び耐遅れ破壊性を付与したヘッダー用鋼である。That is, the present invention includes C: 0.20-0.50%, Si≦0.10%, MnS 1.60%, P≦0.0
15%, S≦0.005%, and further Cr: 0.
01-20% and Al: 0.005-0.0! 50%
0.1-20% of Ni, Mo:
0.1-1.0%, V: 0.01-0.50% and B: 0.0005-0.0050%, and the remainder is Fe and inevitable impurities. This header steel is characterized by having a composition consisting of the following, and has excellent header properties and delayed fracture resistance.
以下に本発明を実施例に基づいて詳述する。The present invention will be explained in detail below based on examples.
まず１本発明鋼における成分並びにその含有量限定理由
を説明する。First, the components in the steel of the present invention and the reasons for limiting their contents will be explained.
Ｃ：
Ｃはヘッダー用鋼として要求される強度を付与するため
に有効な元素であり、０．２０％以上を必要とする。し
かし、多くすると強度が高くなるものの、靭性及び耐遅
れ破壊性が劣化するので、０．５０％を上限とする。C: C is an effective element for imparting the strength required for header steel, and requires 0.20% or more. However, if the content is increased, the strength increases, but the toughness and delayed fracture resistance deteriorate, so the upper limit is set at 0.50%.
Ｓｉ：
Ｓｉは、溶製時に不純物として混入する元素であり、フ
ェライト中に固溶し、焼きなまし時の強度を高め、すな
わち変形抵抗を高める元素である。Si: Si is an element that is mixed as an impurity during melting, and is a solid solution in ferrite that increases the strength during annealing, that is, increases the deformation resistance.
本発明ではＳｉ量は低ければ低いほど良いが、溶製上の
技術面を考慮して０．１０％を上限とする。In the present invention, the lower the amount of Si, the better, but considering the technical aspect of melting, the upper limit is set at 0.10%.
Ｍｎ：
ＭｎはＳｉと同様、不純物として混入する元素であり、
焼入れに先立つオーステナイト化時において旧オーステ
ナイト粒界へのＰの偏析を助長し粒界を脆化させて酎遅
れ破壊性を劣化させるので。Mn: Like Si, Mn is an element mixed as an impurity,
During austenitization prior to quenching, it promotes the segregation of P to prior austenite grain boundaries, embrittles the grain boundaries, and deteriorates delayed fracture properties.
Ｍｎ量は低ければ低いほど良い。１．６％以上で上記の
傾向が大きいので、これを上限とする。The lower the Mn content, the better. Since the above tendency is significant at 1.6% or more, this is set as the upper limit.
Ｐ二
Ｐは粒界に偏析して粒界を脆化させ遅れ破壊を助長させ
るので、０．０１５％以下に規制する。Since P2P segregates at grain boundaries, embrittles the grain boundaries, and promotes delayed fracture, it is regulated to 0.015% or less.
Ｓ ：
ＳはＭｎと共に非金属介在物（ＭｎＳ）を形成し、特に
苛酷な八ツダー加工においてはこの非金属介在物が基点
となって破壊を生じ、変形能を劣化させることになるの
で、０．００５％以下に規制する。S: S forms non-metallic inclusions (MnS) together with Mn, and in particularly severe Yatsuda machining, these non-metallic inclusions serve as starting points to cause fractures and deteriorate deformability, so 0 Regulated to .005% or less.
Ｃｒ：
Ｃｒは焼入れ性を向上する元素であり、そのためには０
．０１％以上を添加する必要があり、多いほど良いが、
経済性を考慮して２０％を上限とする。Cr: Cr is an element that improves hardenability, and for that purpose 0
．． It is necessary to add 0.01% or more, the more the better.
Considering economic efficiency, the upper limit is set at 20%.
Ａｌ、：
ＡｌはＳｉに代替する脱酸剤として添加する元素であり
、しかも結晶粒を細粒化するのに効果的な元素でもある
。そのために０．００５％以上を添加する必要があるが
、あまり多く添加しても効果が飽和するので０．０５０
％を上限とする。Al: Al is an element added as a deoxidizing agent to replace Si, and is also an effective element for refining crystal grains. For this reason, it is necessary to add 0.005% or more, but if too much is added, the effect will be saturated, so 0.05%
The upper limit is %.
Ｎｉ、Ｍｏ、Ｖ％Ｂ：
ヘッダー用鋼に要求される通常の強度は上記Ｃ量によっ
て得られるが、焼入性を向上させたい場合には、Ｎｉ、
Ｍｏ、■及びＢのうちの１種又は２種以上を適量添加す
ることができる。添加するときはＮｉ、Ｍｏ、Ｖを各々
０．０１％以上とし、Ｂは０．０００５％以上とする。Ni, Mo, V%B: The normal strength required for header steel can be obtained by the above amount of C, but if you want to improve hardenability, Ni,
Appropriate amounts of one or more of Mo, (1) and B can be added. When added, Ni, Mo, and V are each 0.01% or more, and B is 0.0005% or more.
しかし、多く添加しても上記効果が飽和し、強度が高く
なりすぎるとヘッダー性の劣化を招くので、Ｎｉは２０
％、Ｍｏは１．０％、■は０．５０％、Ｂは０．００５
０％を上限とする。However, even if a large amount of Ni is added, the above effect will be saturated, and if the strength becomes too high, the header properties will deteriorate.
%, Mo is 1.0%, ■ is 0.50%, B is 0.005
The upper limit is 0%.
なお、上記組成のヘッダー用鋼は主としてボルト類を対
象とするが、線材として或いは棒線材として類似の機械
構造部品の加工に供し得ることは云うまでもない。その
際、冷間ヘッダー加工に先立って焼なまし処理を施し、
加工後は焼入れ、焼もどしにより調質されるのが通例で
ある。Although the header steel having the above composition is mainly used for bolts, it goes without saying that it can also be used as a wire rod or rod for processing similar mechanical structural parts. At that time, annealing treatment is performed prior to cold header processing,
After processing, it is usually tempered by quenching and tempering.
本発明鋼は、か＼る製造プロセスにおいて優れた八ツダ
ー加工性を有するので、変形抵抗が小さく、苛酷なヘッ
ダーを行っても割れが発生しにくく、また加工後の製品
使用時においては、特に耐遅れ破壊性が優れているので
、高強度域でも信頼性を確保することができる。The steel of the present invention has excellent eight-dimensional workability in the manufacturing process, so it has low deformation resistance and is less prone to cracking even when subjected to severe headers, and is particularly suitable for use after processing. Since it has excellent delayed fracture resistance, reliability can be ensured even in the high strength range.
（実施例）
第１表に示す化学成分（ｗｔ％）の各種鋼を溶製し、１
５ｍｍφの線材に圧延し、球状化焼なましを施した後に
引張試験及び圧縮試験を実施して機械的性質並びに限界
圧縮率による変形能を調べた。(Example) Various steels with chemical compositions (wt%) shown in Table 1 were melted, and 1
After rolling into a wire rod of 5 mm diameter and annealing it to form a spheroid, a tensile test and a compression test were conducted to examine the mechanical properties and the deformability depending on the limit compressibility.
なお、上記焼なまし処理は第１図に示す加熱温度、保持
時間及び冷却条件により行った。また限界圧縮率は第２
図に示す如く６φＸ １２ （ｍｍ）の円柱状体（高さ
ｒ−ｏ ）を圧縮し、割れが発生したときの高さくＬ）
を求め、 （（Ｌ、−Ｌ）／Ｌ、）Ｘ１００（％）に
て求めた。The above annealing treatment was carried out under the heating temperature, holding time and cooling conditions shown in FIG. Also, the critical compression ratio is the second
As shown in the figure, a cylindrical body (height ro) of 6φX 12 (mm) is compressed, and the height when a crack occurs is L)
was calculated using ((L, -L)/L,)X100(%).
以上の各試験の結果を第２表に示す。The results of each of the above tests are shown in Table 2.
次いで、使用状態での耐遅れ破壊性を調べるために、第
３表に示す焼入れ温度、焼もどし温度にて焼入れ、焼も
どし処理を施して同表に示す硬さに調質した後、遅れ破
壊強度比（σ３ｏｈｒ／σｓｅ）を求めた。その際、本
発明ｍ（Ｌ）（Ｎα１〜２）はＨＲ（，３６〜３７（１
１５〜１２０ｋｇｆ ／ｍｍ２）に、本発明鋼（２）
（Ｎα４〜９）はＨＲＣ４２〜４３（１３０〜１４０ｋ
ｇｆ ／＋ｎｏ＋”）に各々調質して耐遅れ破壊性を評
価した。Next, in order to examine the delayed fracture resistance under use, the hardening and tempering treatments were performed at the quenching and tempering temperatures shown in Table 3, and the hardness was tempered to the hardness shown in the same table. The intensity ratio (σ3ohr/σse) was determined. At that time, the present invention m(L) (Nα1-2) is HR(,36-37(1
15 to 120 kgf/mm2), the invention steel (2)
(Nα4-9) is HRC42-43 (130-140k
gf /+no+") to evaluate delayed fracture resistance.
なお、遅れ破壊試験方法としては、第３図に示す形状、
寸法（Ｉｌｍ）の試験片を準備し、第４図に示す如くこ
の試験片１の一端をホルダー２で支持すると共に他端に
モーメントアーム３を取り付け、試験片１の中央から４
００ｍｍの位置にあるモーメントアーム先端に重り４を
懸吊して試験片１に曲げ応力をかけた。試験片１の中央
には０．ＩＮの塩酸を常時滴下した。応力（公称曲げ応
力）と破断までの時間の関係を求めて遅れ破壊曲線を作
製した後、３０ｈｒにおける時間強度を読みとり、静曲
げ応力（σｓｏ）に対する３０時間強度（σ：１Ｏｈｒ
）の比を遅れ破壊強度比（σ、、ｈｒ／σｓＢ）とした
。In addition, as a delayed fracture test method, the shape shown in Fig. 3,
A test piece having a size (Ilm) is prepared, one end of this test piece 1 is supported by a holder 2, and a moment arm 3 is attached to the other end as shown in FIG.
A weight 4 was suspended from the tip of the moment arm at a position of 00 mm to apply bending stress to the test piece 1. 0.0 in the center of test piece 1. IN hydrochloric acid was constantly added dropwise. After determining the relationship between stress (nominal bending stress) and time to fracture and creating a delayed fracture curve, the time strength at 30 hours was read, and the 30 hour strength (σ: 1 Ohr) was calculated relative to the static bending stress (σso).
) was defined as the delayed fracture strength ratio (σ, hr/σsB).
【以下余白１
第２表かられかるように１本発明鋼（１）、（２）はい
ずれも引張強さ、０．２％耐力が低く、変形抵抗が小さ
いことを示し、また限界圧縮率が大きく、変形能が向上
していることを示し、したがって八ッグー性が優れてい
る。[Margin below 1 As seen from Table 2, both the invention steels (1) and (2) have low tensile strength, 0.2% proof stress, low deformation resistance, and limit compressibility. is large, indicating improved deformability, and therefore has excellent eight-glue properties.
また、第３表に示すように、焼入れ、焼もどしを施した
後の使用状態における耐遅れ破壊性についても１本発明
鋼（１）、（２）のいずれも各強度域において遅れ破壊
強度比が大きく、特に高強度域でも優れた耐遅れ破壊性
を示している。In addition, as shown in Table 3, regarding the delayed fracture resistance in the service state after quenching and tempering, both of the invention steels (1) and (2) have delayed fracture strength ratios in each strength range. is large, showing excellent delayed fracture resistance, especially in the high strength range.
（発明の効果）
以上詳述したように１本発明によれば、ヘッダー用鋼に
つきＣを適正量にすると共に不純物成分としてのＳｉ、
Ｍｎ、Ｐ、Ｓを規制し、更にＣｒ、Ａｌを適当量添加し
、必要に応じてＮｉ、Ｍｏ、Ｖ、Ｂのうちの１種又は２
種以上を適当量添加するものであるから、八ツグー性が
優れ、しかも耐遅れ破壊性が特に高強度域での使用状態
でも優れているため、苛酷な八ツグーによっても割れが
発生することなく製品歩留りが向上でき、使用時での信
頼性も向上することができる。(Effects of the Invention) As detailed above, according to the present invention, in addition to setting an appropriate amount of C in header steel, Si as an impurity component,
Control Mn, P, and S, further add appropriate amounts of Cr and Al, and add one or two of Ni, Mo, V, and B as necessary.
Since it contains a suitable amount of 50% or more, it has excellent 80% resistance, and its delayed fracture resistance is also excellent even in high-strength use conditions, so it will not crack even under severe 80% strength. Product yield can be improved and reliability during use can also be improved.
第１図は焼なまし条件を示す図、
第２図は圧縮試験で限界圧縮率の求め方を説明する図、
第３図乃至第５図は遅れ破壊試験方法を説明する図、第
３図は試験片の形状、寸法（ｍｍ）を示す図、第４図は
試験方法を示す図、第５図は遅れ破壊強度比の求め方を
示す図である。
１・・・遅れ破壊試験片、 ２・・・ホルダー。
３・・・モーメントアーム、 ４・・・重り。
特許出願人 大同特殊鋼株式会社
代理人弁理士 中 村 尚
第１図
第３図
第４図
第５図
時間Figure 1 is a diagram showing the annealing conditions, Figure 2 is a diagram explaining how to determine the limit compressibility in a compression test, Figures 3 to 5 are diagrams explaining the delayed fracture test method, Figure 3 4 is a diagram showing the shape and dimensions (mm) of the test piece, FIG. 4 is a diagram showing the test method, and FIG. 5 is a diagram showing how to determine the delayed fracture strength ratio. 1... Delayed fracture test piece, 2... Holder. 3... Moment arm, 4... Weight. Patent applicant: Daido Steel Co., Ltd. Patent attorney Hisashi Nakamura Figure 1 Figure 3 Figure 4 Figure 5 Time
Claims (2)
０％を含み、Ｓｉ≦０．１０％、Ｍｎ≦１．６０％、Ｐ
≦０．０１５％、Ｓ≦０．００５％に規制すると共にＣ
ｒ：０．０１〜２．０％、Ａｌ：０．００５〜０．０５
０％を含み、残部がＦｅ及び不可避的不純物からなるこ
とを特徴とするヘッダー性及び耐遅れ破壊性の優れたヘ
ッダー用鋼。(1) In weight% (the same applies hereinafter), C: 0.20 to 0.5
0%, Si≦0.10%, Mn≦1.60%, P
≦0.015%, S≦0.005% and C
r: 0.01-2.0%, Al: 0.005-0.05
A header steel with excellent header properties and delayed fracture resistance, characterized by containing 0% Fe and the remainder consisting of Fe and unavoidable impurities.
０％、Ｍｎ≦１．６０％、Ｐ≦０．０１５％、Ｓ≦０．
００５％に規制すると共にＣｒ：０．０１〜２．０％及
びＡｌ：０．００５〜０．０５０％を含み、更にＮｉ：
０．１〜２．０％、Ｍｏ：０．１〜１．０％、Ｖ：０．
０１〜０．５０％及びＢ：０．０００５〜０．００５０
％のうちの１種又は２種以上を含み、残部がＦｅ及び不
可避的不純物からなることを特徴とするヘッダー性及び
耐遅れ破壊性の優れたヘッダー用鋼。(2) Contains C: 0.20-0.50%, Si≦0.1
0%, Mn≦1.60%, P≦0.015%, S≦0.
005% and contains Cr: 0.01-2.0% and Al: 0.005-0.050%, and further Ni:
0.1-2.0%, Mo: 0.1-1.0%, V: 0.
01-0.50% and B: 0.0005-0.0050
A header steel having excellent header properties and delayed fracture resistance, characterized in that the remainder is Fe and inevitable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3937486A JPS62199751A (en) | 1986-02-25 | 1986-02-25 | Steel for header |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3937486A JPS62199751A (en) | 1986-02-25 | 1986-02-25 | Steel for header |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62199751A true JPS62199751A (en) | 1987-09-03 |
Family
ID=12551262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3937486A Pending JPS62199751A (en) | 1986-02-25 | 1986-02-25 | Steel for header |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62199751A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63259053A (en) * | 1987-01-29 | 1988-10-26 | イスコール リミテッド | High strength and high toughness steel round rod material and its production |
| JPH02145744A (en) * | 1988-11-29 | 1990-06-05 | Kawasaki Steel Corp | Carbon steel for machine structural use having excellent cold forgeability and induction hardenability |
-
1986
- 1986-02-25 JP JP3937486A patent/JPS62199751A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63259053A (en) * | 1987-01-29 | 1988-10-26 | イスコール リミテッド | High strength and high toughness steel round rod material and its production |
| JPH02145744A (en) * | 1988-11-29 | 1990-06-05 | Kawasaki Steel Corp | Carbon steel for machine structural use having excellent cold forgeability and induction hardenability |
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