JPH10195590A - High strength and high toughness non-heat treated steel - Google Patents
High strength and high toughness non-heat treated steelInfo
- Publication number
- JPH10195590A JPH10195590A JP35756996A JP35756996A JPH10195590A JP H10195590 A JPH10195590 A JP H10195590A JP 35756996 A JP35756996 A JP 35756996A JP 35756996 A JP35756996 A JP 35756996A JP H10195590 A JPH10195590 A JP H10195590A
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- steel
- heat treated
- strength
- toughness
- treated steel
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、焼入れ焼戻しを行
わなくとも熱間加工まま若しくは焼ならしのみで、削岩
用部品に必要な強度と靱性を有し、かつ安価な鋼に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive steel having the strength and toughness required for rock drilling parts without quenching and tempering, as it is while hot working or normalizing.
【０００２】[0002]
【従来技術】鉱業および土木建築の分野においてチゼル
やロッドなどの削岩用部品は、HRC40 以上と高強度はも
ちろん、衝撃による高靱性が特に要求されるため、機械
構造用合金鋼であるSCR 、SCM およびSNCMや中空鋼であ
るSKC などの低合金強靱鋼を調質して使用されている。
これらの部品は、その他の機械部品に比べれば摩耗や折
損などにより寿命が極めて短時間であることから、消耗
部品として位置付けられており、寿命を改善するには合
金元素が多量添加されたものへと選択されるため、コス
トアップの要因となっていた。そこで、コストダウンを
目的として合金元素を減らしても、強度および靱性を確
保することは困難であることから、調質処理を省略もし
くは焼きならしままで強度と靱性を有する鋼の開発が望
まれている。2. Description of the Related Art In the fields of mining and civil engineering, rock drilling components such as chisel and rods are required to have not only high strength of HRC40 or more but also high toughness due to impact. SCM and SNCM and low alloy tough steel such as hollow steel SKC are used after tempering.
Since these parts have a very short life due to wear and breakage compared to other mechanical parts, they are positioned as consumable parts. This was a factor in cost increase. Therefore, it is difficult to secure the strength and toughness even if the alloying elements are reduced for the purpose of cost reduction.Therefore, the development of steel with strength and toughness up to omission of tempering treatment or normalizing is desired. I have.
【０００３】このような要求に対し、熱処理省略もしく
は簡略に寄与する鋼としては、非調質鋼がある。非調質
鋼は、調質処理を施すことなく熱間加工−空冷まま若し
くは焼ならしままで所望の硬さを有することから、熱処
理コストの低減およびリードタイムの短縮の効果が大き
く、主に自動車および建設機械部品で適用が拡大されて
きた。ただ強度的に見て硬さHRC30 以下の非調質鋼が適
用されているのがほとんどで、高強度を図るほど靱性が
低下することから、掘削用および鉱山機械用の掘削部品
に実用化された例はいままでない。[0003] As a steel that contributes to the omission or simplification of the heat treatment to such a demand, there is a non-heat treated steel. Since non-heat treated steel has the desired hardness from hot working to air cooling or normalizing without heat treatment, the effect of reducing heat treatment cost and lead time is significant. And its application has expanded in construction machinery parts. However, in terms of strength, non-heat treated steel with a hardness of HRC30 or less is mostly used, and the higher the strength, the lower the toughness.Therefore, it is practically used for drilling parts for drilling and mining equipment. There has never been an example.
【０００４】[0004]
【発明が解決しようとする課題】本発明は上記の問題点
を解決するものであり、熱間加工まま若しくは焼ならし
のみで硬さがHRC40 以上、衝撃値が従来の調質鋼と同等
の2UE20℃＝49J/cm2 (2mmＵノッチシャルピー衝撃試験
片による20℃での衝撃値）以上を有する鋼を安価に提供
することを目的とする。SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and has a hardness equal to or more than HRC40 and an impact value equivalent to that of a conventional tempered steel by hot working or normalizing only. An object of the present invention is to provide inexpensively a steel having 2U E 20 ° C. = 49 J / cm 2 (impact value at 20 ° C. by a 2 mm U notch Charpy impact test piece).
【０００５】[0005]
【課題を解決するための手段】重量比で、C:0.20〜0.35
% 、Si:1.5〜2.5%、Mn:1.8〜2.5%、Cr:0.3〜1.0%、Al:
0.005〜0.05% 、Ti:0.005〜0.05% 、V:0.05〜0.5%、N:
0.008 〜0.05% を含有し、残部がFeおよび不可避不純物
からなることを特徴とする高強度高靱性非調質鋼であ
る。[Means for Solving the Problems] By weight ratio, C: 0.20 to 0.35
%, Si: 1.5-2.5%, Mn: 1.8-2.5%, Cr: 0.3-1.0%, Al:
0.005-0.05%, Ti: 0.005-0.05%, V: 0.05-0.5%, N:
This is a high-strength, high-toughness, non-heat treated steel containing 0.008 to 0.05%, with the balance being Fe and unavoidable impurities.
【０００６】また、上記の鋼成分において、さらに、N
i:0.1〜2.0%、Mo:0.05 〜1.0%、B:0.0005〜0.005%から
選んだ１種または２種以上の元素を含有せしめたことを
特徴とする高強度高靱性非調質鋼である。[0006] In the above steel components, N
i: 0.1 to 2.0%, Mo: 0.05 to 1.0%, B: 0.0005 to 0.005%. A high-strength, high-toughness non-heat treated steel characterized by containing one or more elements selected from the group consisting of: .
【０００７】鋼の高強度高靱性を達成するために、本発
明ではコスト的に安価なSiの効果について検討した。Si
はフェライト中に固溶して強化する元素であることは従
来からの知見であるが、靱性に対する影響は知られてい
なかった。本発明ではSi量を変化させた鋼を溶製し、熱
間加工ままおよび焼きならし後の衝撃特性を調査したと
ころ、Si量の増加に伴って強度は上昇するが、靱性が全
く劣化しないことを見出した(図１および図２参照）。
特にHRC40 以上では機械構造用合金鋼であるSCR、SCM
の調質材と同等以上の靱性を有することを見出した。[0007] In order to achieve high strength and high toughness of steel, the present invention examined the effect of Si which is inexpensive in terms of cost. Si
Is a known element that forms a solid solution in ferrite and strengthens it, but its influence on toughness was not known. In the present invention, steel with varied Si content is melted, and the impact characteristics after hot working and after normalizing are investigated, the strength increases with an increase in Si content, but the toughness does not deteriorate at all. (See FIGS. 1 and 2).
In particular, SCR and SCM which are alloy steels for machine
It has been found that it has toughness equal to or higher than that of the tempered material.
【０００８】本発明ではさらにコスト的に高価な元素で
あるNiの効果についても確認し、機械構造用合金鋼SNCM
や中空鋼SKC に添加されるNi量の半分以下で、熱間加工
まま若しくは焼きならしのみでSNCM以上、SKC 同等の衝
撃特性を有することも見出した。In the present invention, the effect of Ni, which is an element that is more expensive in terms of cost, was also confirmed, and the alloy steel SNCM for machine structure was used.
It was also found that, with less than half the amount of Ni added to SKC and hollow steel, the impact properties were as high as SNCM and equivalent to SKC with hot working or normalizing only.
【０００９】以下に本発明の成分の限定理由を述べる。 C:0.20〜0.35% C は、強度を確保するのに必須の元素であり、0.20% 以
上を必要とする。しかし、多すぎると靱性が劣化するの
で0.35% 以下とする。The reasons for limiting the components of the present invention are described below. C: 0.20 to 0.35% C is an essential element for securing strength, and requires 0.20% or more. However, if the content is too large, the toughness deteriorates.
【００１０】Si:1.5〜2.5% Siは、溶製時の脱酸材であるが、本発明では高強度高靱
性を達成するのに安価な元素であり、掘削用部品として
要求される強度を満足させるには1.5%以上を必要とす
る。しかし、多量に添加するとその効果は飽和し、却っ
て靱性を劣化させるので2.5%を上限とする。Si: 1.5 to 2.5% Si is a deoxidizing material at the time of smelting. In the present invention, Si is an inexpensive element for achieving high strength and high toughness. You need more than 1.5% to be satisfied. However, if a large amount is added, the effect is saturated and the toughness is rather deteriorated. Therefore, the upper limit is 2.5%.
【００１１】Mn:1.8〜2.5% Mnは、Siと同様に溶製時の脱酸材であるが、強度および
靱性を確保する元素である。その効果を得るには1.8%以
上を必要とし、2.5%以上ではその効果は飽和するので、
上限を2.5%とする。Mn: 1.8 to 2.5% Mn is a deoxidizing material at the time of melting, like Si, but is an element that ensures strength and toughness. To obtain the effect, you need 1.8% or more, and at 2.5% or more, the effect is saturated,
The upper limit is set to 2.5%.
【００１２】Cr:0.3〜1.0% Crは、強度確保するのに必須の元素であり、その効果を
発揮するには0.3%以上を必要とする。しかし、多すぎる
と靱性が劣化するので1.0%を上限とする。Cr: 0.3 to 1.0% Cr is an essential element for securing the strength, and 0.3% or more is required to exhibit its effect. However, if it is too large, the toughness deteriorates, so the upper limit is made 1.0%.
【００１３】Al:0.005〜0.05% Alは、SiおよびMnと同様に溶製時の脱酸材であるが、N
と結合してAlN を生成し、熱間加工時もしくは焼きなら
し時の結晶粒粗大化を防止するのに必須の元素である。
その効果を得るには0.005%以上を必要とし、多すぎると
介在物を形成して機械的性質が劣化するので0.05% 以下
とする。Al: 0.005 to 0.05% Al is a deoxidizing material at the time of melting like Si and Mn.
Is an element essential for preventing the formation of coarse grains during hot working or normalizing.
To obtain the effect, 0.005% or more is required. If it is too much, inclusions are formed and mechanical properties are deteriorated.
【００１４】Ti:0.005〜0.05% Tiは、Alと同様に結晶粒粗大化を防止する元素として必
須の元素であり、0.005%以上を必要とする。しかし、多
すぎるとその効果は飽和し、コストアップとなるため0.
05% を上限とする。Ti: 0.005 to 0.05% Ti is an essential element for preventing crystal grain coarsening like Al, and requires 0.005% or more. However, if the amount is too large, the effect will be saturated and the cost will increase.
The upper limit is 05%.
【００１５】V:0.05〜0.5% V は、鋼中に固溶して強度および靱性を確保するのに必
要な元素であり、0.05% 以上を必要とする。しかし、多
すぎるとその効果は飽和し、コストアップとなるため0.
5%を上限とする。V: 0.05 to 0.5% V is an element necessary for solid solution in steel to secure strength and toughness, and requires 0.05% or more. However, if the amount is too large, the effect will be saturated and the cost will increase.
5% is the upper limit.
【００１６】N:0.008 〜0.05% N は、AlN を生成する元素であり、0.008%以上を必要と
する。しかし、多すぎるとその効果は飽和し、また熱間
加工性を劣化させるため0.05% 以下とする。N: 0.008 to 0.05% N is an element that forms AlN, and requires 0.008% or more. However, if the content is too large, the effect is saturated and the hot workability is deteriorated.
【００１７】Ni:0.1〜2.0% Niは、靱性を確保するのに必須の元素であり、また質量
効果が大きくなると冷却速度の低下により硬さが低下す
るため、少なくとも0.1%以上を必要とする。しかし、多
量に添加するとその効果は飽和し、またコストが上昇す
るため2.0%を上限とする。Ni: 0.1 to 2.0% Ni is an essential element for securing toughness, and when the mass effect is increased, the cooling rate is lowered to lower the hardness, so that at least 0.1% or more is required. . However, if a large amount is added, the effect is saturated and the cost increases, so the upper limit is 2.0%.
【００１８】Mo:0.05 〜1.0% Moも、Niと同様の効果が有り、0.05% 以上を必要があ
る。しかし、多すぎるとその効果は飽和し、コストが上
昇するため1.0%を上限とする。Mo: 0.05 to 1.0% Mo also has the same effect as Ni, and needs to be 0.05% or more. However, if the amount is too large, the effect is saturated and the cost increases, so the upper limit is 1.0%.
【００１９】B:0.0005〜0.005% B も、Niと同様の効果が有り、そして質量効果が大きい
ときに冷却能の違いによる機械的性質のバラツキを抑え
るための元素であり、少なくとも0.0005% を必要とす
る。しかし、多量に添加するとその効果は飽和するので
0.005%を上限とする。B: 0.0005 to 0.005% B also has the same effect as Ni, and is an element for suppressing a variation in mechanical properties due to a difference in cooling capacity when the mass effect is large. At least 0.0005% is necessary. And However, the effect is saturated when added in large amounts, so
The upper limit is 0.005%.
【００２０】[0020]
【発明の実施の形態】本願発明の実施の形態を以下に記
す。請求項１の発明の形態は、重量比にて、C:0.20〜0.
35% 、Si:1.5〜2.5%、Mn:1.8〜2.5%、Cr:0.3〜1.0%、A
l:0.005〜0.05% 、Ti:0.005〜0.05% 、V:0.05〜0.5%、
N:0.008 〜0.05% を含有し、残部がFeおよび不可避不純
物からなる高強度高靱性非調質鋼である。Embodiments of the present invention will be described below. According to the embodiment of the present invention, C: 0.20 to 0.2 in weight ratio.
35%, Si: 1.5-2.5%, Mn: 1.8-2.5%, Cr: 0.3-1.0%, A
l: 0.005-0.05%, Ti: 0.005-0.05%, V: 0.05-0.5%,
N: A high-strength, high-toughness non-heat treated steel containing 0.008 to 0.05%, with the balance being Fe and unavoidable impurities.
【００２１】請求項２の発明の実施の形態は、上記の請
求項１の実施の形態の鋼において、さらに、Ni:0.1〜2.
0%、Mo:0.05 〜1.0%または．0.0005〜0.05% から選んだ
１種または２種以上の成分を含有し、残部がFeおよび不
可避不純物からなる高強度高靱性非調質鋼である。According to a second aspect of the present invention, there is provided the steel according to the first aspect of the present invention, wherein Ni: 0.1-2.
0%, Mo: 0.05 to 1.0% or. It is a high-strength, high-toughness non-heat treated steel containing one or more components selected from 0.0005 to 0.05%, with the balance being Fe and unavoidable impurities.
【００２２】[0022]
【実施例】以下に本発明の実施例について説明する。表
１に示す成分を100Kkg真空溶解炉にて溶製し、100Kkg鋼
塊へ鋳造した後、加熱温度1200℃にて外径φ30mmの丸棒
へ鍛伸した。番号１〜７は発明鋼、番号８〜１２は比較
鋼、番号１３〜１５は従来鋼である。ここで番号８およ
び９はそれぞれSiおよびTiが下限以下であり、番号１０
はC が上限以上である。番号１１はMnが下限以下であ
り、番号１２はCrが上限以上である。また番号１３はSC
R440、番号１４はSCM440、番号１５はSNCM439、番号１
６はSNCM630 、番号１７はSKC24 である。Embodiments of the present invention will be described below. The components shown in Table 1 were melted in a 100 kg vacuum melting furnace, cast into a 100 kg steel ingot, and then forged into a round bar having an outer diameter of 30 mm at a heating temperature of 1200 ° C. Numbers 1 to 7 are invention steels, numbers 8 to 12 are comparative steels, and numbers 13 to 15 are conventional steels. Here, in Nos. 8 and 9, Si and Ti are respectively lower than the lower limit, and
Is such that C is greater than or equal to the upper limit. In number 11, Mn is lower than the lower limit, and in number 12, Cr is higher than the upper limit. Number 13 is SC
R440, number 14 is SCM440, number 15 is SNCM439, number 1
6 is SNCM630, and number 17 is SKC24.
【００２３】表１の材料のうち、発明鋼および比較鋼
（番号１〜１２）の衝撃試験と硬さの結果を表２に示し
た。発明鋼はすべて、硬さHRC40 以上、衝撃値49J/cm2
を満足している。番号８は、衝撃値は満足しているもの
の硬さを満足していない。番号９および１２は硬さは満
足しているものの衝撃値を満足していない。番号１０お
よび番号１１は硬さおよび衝撃値ともに満足していな
い。Table 2 shows the results of the impact test and hardness of the invention steels and comparative steels (Nos. 1 to 12) among the materials shown in Table 1. All invention steels have hardness of HRC40 or more and impact value of 49 J / cm 2
Are satisfied. In No. 8, the impact value was satisfied but the hardness was not satisfied. Nos. 9 and 12 satisfy the hardness but do not satisfy the impact value. Nos. 10 and 11 do not satisfy both hardness and impact value.
【００２４】[0024]
【表１】 [Table 1]
【００２５】さらに、発明鋼と従来鋼の比較を行った結
果を図３に示す。なお、従来鋼は焼入処理を行った後、
焼戻し温度を変えて種々の硬さが得られるように処理を
行った。従来鋼と比較して発明鋼は、同等若しくはそれ
以上の衝撃特性が得られていることがわかる。特に発明
鋼番号２および３は、硬さが同一レベルの従来鋼番号１
５および１６の半分以下のＮｉ量で衝撃特性が上回って
いることから素材費のコストダウンを図ることが可能と
なる。FIG. 3 shows the results of comparison between the inventive steel and the conventional steel. In addition, after the conventional steel is quenched,
The treatment was performed so as to obtain various hardnesses by changing the tempering temperature. It can be seen that the invention steel has equal or better impact characteristics than the conventional steel. In particular, inventive steel numbers 2 and 3 are conventional steel numbers 1 having the same level of hardness.
Since the impact characteristics are superior when the Ni content is less than half of 5 and 16, the material cost can be reduced.
【００２６】[0026]
【表２】 [Table 2]
【００２７】[0027]
【発明の効果】本発明によれば、チゼル、アンカーを始
めとして掘削用部品に適用されてきた機械構造用合金鋼
および中空鋼の代替が可能であり、調質処理省略による
コスト削減だけでなく、リードタイムの短縮になり、ま
たNi含有鋼では従来鋼の半分以下のNi量で同等の特性を
有することから、素材費のコストダウンにも寄与できる
など優れた効果を奏するものである。According to the present invention, it is possible to replace alloy steel and hollow steel for machine structural use which have been applied to excavating parts such as chisels and anchors, and not only to reduce costs by omitting tempering treatment, but also to reduce costs. In addition, since the lead time is shortened, and the Ni-containing steel has the same characteristics with less than half of the amount of the conventional steel, it has excellent effects such as being able to contribute to a reduction in material costs.
【図１】鋼材の硬さに及ぼすSi量の影響を示すグラフで
ある。FIG. 1 is a graph showing the effect of the amount of Si on the hardness of a steel material.
【図２】衝撃値に及ぼすSi添加による硬さの影響を示す
グラフである。FIG. 2 is a graph showing the effect of hardness by addition of Si on impact value.
【図３】実施例における発明鋼と従来鋼の衝撃値と硬さ
の関係を示すグラフである。FIG. 3 is a graph showing the relationship between the impact value and the hardness of the inventive steel and the conventional steel in Examples.
Claims (2)
2.5%、Mn:1.8〜2.5%、Cr:0.3〜1.0%、Al:0.005〜0.05%
、Ti:0.005〜0.05% 、V:0.05〜0.5%、N:0.008 〜0.05%
を含有し、残部がFeおよび不可避不純物からなる高強
度高靱性非調質鋼。(1) C: 0.20 to 0.35% by weight, Si: 1.5 to
2.5%, Mn: 1.8-2.5%, Cr: 0.3-1.0%, Al: 0.005-0.05%
, Ti: 0.005-0.05%, V: 0.05-0.5%, N: 0.008-0.05%
A high-strength, high-toughness non-heat-treated steel containing Fe and inevitable impurities.
に、Ni:0.1〜2.0%、Mo:0.05 〜1.0%、B:0.0005〜0.005%
から選んだ元素１種または２種以上を含有し、残部がFe
および不可避不純物からなる高強度高靱性非調質鋼。2. The steel composition according to claim 1, further comprising: Ni: 0.1 to 2.0%, Mo: 0.05 to 1.0%, B: 0.0005 to 0.005%.
Contains one or more elements selected from the group consisting of Fe
High-strength, high-toughness non-heat treated steel consisting of unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35756996A JPH10195590A (en) | 1996-12-27 | 1996-12-27 | High strength and high toughness non-heat treated steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35756996A JPH10195590A (en) | 1996-12-27 | 1996-12-27 | High strength and high toughness non-heat treated steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10195590A true JPH10195590A (en) | 1998-07-28 |
Family
ID=18454798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35756996A Pending JPH10195590A (en) | 1996-12-27 | 1996-12-27 | High strength and high toughness non-heat treated steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10195590A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100619841B1 (en) | 2004-11-24 | 2006-09-08 | 송치복 | High elasticity and high strength steel in the composition of high silicon with low alloy for the purpose of impact resistance and abrasion resistance and manufacturing method of the same steel |
-
1996
- 1996-12-27 JP JP35756996A patent/JPH10195590A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100619841B1 (en) | 2004-11-24 | 2006-09-08 | 송치복 | High elasticity and high strength steel in the composition of high silicon with low alloy for the purpose of impact resistance and abrasion resistance and manufacturing method of the same steel |
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