JPS6358891B2 - - Google Patents
Info
- Publication number
- JPS6358891B2 JPS6358891B2 JP2327080A JP2327080A JPS6358891B2 JP S6358891 B2 JPS6358891 B2 JP S6358891B2 JP 2327080 A JP2327080 A JP 2327080A JP 2327080 A JP2327080 A JP 2327080A JP S6358891 B2 JPS6358891 B2 JP S6358891B2
- Authority
- JP
- Japan
- Prior art keywords
- wire
- tempering
- conveyor
- less
- cooled
- 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
- 238000005496 tempering Methods 0.000 claims description 24
- 229910000831 Steel Inorganic materials 0.000 claims description 23
- 239000010959 steel Substances 0.000 claims description 23
- 238000001816 cooling Methods 0.000 claims description 20
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 238000010622 cold drawing Methods 0.000 claims description 6
- 229910000734 martensite Inorganic materials 0.000 claims description 6
- 238000005098 hot rolling Methods 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 238000003303 reheating Methods 0.000 claims description 4
- 229910001566 austenite Inorganic materials 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims 1
- 238000005096 rolling process Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 229910001563 bainite Inorganic materials 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
Description
本発明はPC鋼線、コンクリートヒユーム管用
鋼線等に用いる高張力線材の製造方法に関するも
のである。
従来高張力線材はCr―Mo鋼、Cr鋼、或はMn
鋼の鋼を用い、圧延后一旦冷却されその后再加熱
して焼入、焼戻し処理を行つたのち引抜加工を施
して製造を行つていた。
このように従来法は、圧延後一旦常温に冷却さ
れた線材を再加熱して焼入れを行つていたため、
熱原単位が高く、又製造費および製造設備が嵩む
などの問題があつた。
本発明は上記問題点を解決する事を目的とした
ものであり、特定の成分の鋼を用いかつ圧延後特
定の条件で焼入れを行う事により、従来の再加熱
焼入工程を省略し、更に焼戻し処理と適当な減面
率の冷間引抜きとを組み合わせる事により引張強
度のバラツキが少なく降伏比、比例限及び延性に
優れた従来と同等もしくは同等以上の高張力線材
を製造することを可能とするものである。
更に詳細に述べれば
本発明は衝風焼入れ后の引張強度は140Kg／mm2
以上を有し、焼戻し後の引張強度は引抜加工時の
強度上昇分を勘案して所望強度より約10Kg／mm2下
げ80〜130Kg／mm2となし、最終成品としての引張
強度は90〜140Kg／mm2で強度バラツキが少なく、
降伏比が88〜97％、延性（絞り率）60％以上の高
張力鋼線を得る事を目的とする。
すなわち本発明は、Ｃ：0.20〜0.40％、Si：
0.20〜1.50％、Mn：0.70〜2.50％、Cr：0.10〜
1.50％、Ｂ：0.0002〜0.005％、SolAl0.060％以
下、或は上記成分に更にTi：0.05〜0.15％、Ｖ：
0.03〜0.08％及びNb：0.02〜0.08％のいずれか１
種又は２種以上を含有させ、残部Fe及び不可避
的不純物からなる鋼を、熱間圧延後直ちに500〜
700℃に強制冷却し過冷オーステナイトの状態で
コンベア上に連続したリング状となして展開し、
衝風によつて７℃／sec以上の冷却速度で冷却し
てコンベア上において線材全体をマルテンサイト
組織となした後、200〜300℃の温度範囲で集束装
置にてコイル状に集束し、徐冷してセルフテンパ
ーを行い、その後400〜600℃に再加熱して焼戻し
処理を行つた後減面率10％以下の冷間引抜を施し
所望の引張強度を有する高張力線材を得る事を特
徴とするものである。
次に本発明の成分の限定理由について述べる。
Ｃは鋼に必要な強度と焼入性を与える為に添加さ
れるが、Ｃ量が0.20％未満では、衝風冷却後の強
度140Kg／mm2以上の引張強度が得られず、一方Ｃ
量が0.40％を越えると140Kg／mm2以上の引張強度
を得る事は可能であるが加工性、点溶接性が著し
く劣下し好ましくない。
Siは焼入性の向上、強度および靭性の改善に有
効な元素であるが、Si量が0.20％未満ではその効
果が少なく、Si量が1.50％を越えると延性が劣化
し好ましくない。
Mnは焼入性を向上させる元素であるが、Mn
量が0.70％未満では焼入性向上は期待できず、一
方線材の径（通常5.5〜11mmφ）が小さいのでMn
量を2.50％を越えて添加しなくても十分焼入性は
得られる。
CrはMnと同様焼入性を向上させる元素である
が、Cr量が0.10％未満では焼入性効果は少なく、
Cr量が1.50％を越えて添加しなくてもMnと同様
の理由で十分焼入性は得られる。
ＢもMnと同様焼入性を向上させる元素である
が、Ｂ量が0.0002％未満では焼入性の効果は期待
できず、Ｂ量が0.005％を越えてもより一層の焼
入性効果が得られない。
SolAlは加工性の向上に有効な元素であるが、
SolAl量が0.060％を越えるとかえつて加工性が悪
くなり好ましくない。
一方Ti：0.05〜0.15％、Ｖ：0.03〜0.08％、
Nb：0.02〜0.08％の３元素は焼戻軟化の抑制に有
効な元素であるが、各元素の下限値未満では焼戻
軟化の抑制効果が期待できず、各元素の上限値を
越えると焼戻軟化の抑制効果が飽和するからであ
る。
次に本発明において熱間圧延后の強制冷却温度
を500〜700℃にした理由を説明する。
すなわち過冷オーステナイト化温度を500〜700
℃としたのは、理論的には700℃以上の温度で材
料を冷却してもコンベア上においてマルテンサイ
ト組織を得ることは可能であるが、冷却開始温度
が高くなると必然的に衝風時間が長くなり、従つ
て７℃／sec程度の冷却速度では現実的なコンベ
ア長さの制限があるため、マルテンサイト変態が
完了しないうちに次工程の集束装置によつて集束
されるので、部分的にベイナイト組織が生じ所期
の目的を達成することができないからである。一
方下限の強制冷却温度を500℃としたのは、実際
の圧延作業においては圧延直後極く短時間のうち
にこれより低い温度まで冷却する事は困難だから
である。
衝風による冷却速度を７℃／sec以上としたの
は、冷却速度７℃／sec未満の速度ではベイナイ
ト組織、フエライト組織等が発生し不完全焼入組
織となり好ましくないからである。
一方、衝風にて冷却後、集束装置においてコイ
ル状となす時の線材の温度は200〜300℃が適当で
ある。この温度範囲で集束装置にて集束し徐冷を
行うとセルフテンパーも並行して行われることに
より線材は焼戻しマルテンサイト組織となり、靭
性が向上するとともに巻取時のワレ又は置きワレ
等を防止することができる。
焼戻し温度400〜600℃とする理由は、400℃未
満では青熱脆性域となり又強度バラツキが大きく
なり、600℃をこえると強度の低下が大きくなり
好ましくないからである。
減面率を10％以下とした理由は、10％を越える
と、降伏比、比例限の低下が著しくなるので好ま
しくないからである。
次に本発明の実施例について述べる。
第１表に示す本発明鋼の化学成分の鋼を供試材
とした。
The present invention relates to a method for manufacturing high-tensile wire rods used for PC steel wires, steel wires for concrete humid pipes, and the like. Conventional high tensile strength wire rods are Cr-Mo steel, Cr steel, or Mn
After rolling, the steel was once cooled, then reheated, quenched and tempered, and then drawn. In this way, in the conventional method, the wire rod was once cooled to room temperature after rolling, and then quenched by reheating.
There were problems such as high heat consumption and increased manufacturing costs and manufacturing equipment. The present invention aims to solve the above problems, and by using steel with a specific composition and quenching under specific conditions after rolling, the conventional reheating and quenching process can be omitted, and By combining tempering treatment and cold drawing with an appropriate area reduction rate, it is possible to manufacture high-tensile wire rods with less variation in tensile strength and excellent yield ratio, proportionality limit, and ductility that are equivalent to or better than conventional wire rods. It is something to do. More specifically, the present invention has a tensile strength of 140 kg/mm 2 after blast hardening.
The tensile strength after tempering is approximately 10Kg/ mm2 lower than the desired strength, taking into account the increase in strength during drawing, to 80-130Kg/ mm2 , and the final product has a tensile strength of 90-140Kg. /mm 2 with little strength variation,
The aim is to obtain a high tensile strength steel wire with a yield ratio of 88 to 97% and ductility (reduction ratio) of 60% or more. That is, in the present invention, C: 0.20 to 0.40%, Si:
0.20~1.50%, Mn: 0.70~2.50%, Cr: 0.10~
1.50%, B: 0.0002 to 0.005%, SolAl 0.060% or less, or in addition to the above components Ti: 0.05 to 0.15%, V:
Any one of 0.03-0.08% and Nb: 0.02-0.08%
Immediately after hot rolling, steel containing Fe or two or more species, the remainder being Fe and unavoidable impurities, is heated to a
It is forcibly cooled to 700℃ and is rolled out in a continuous ring shape on a conveyor in the state of supercooled austenite.
After being cooled by air blast at a cooling rate of 7°C/sec or more to make the entire wire into a martensitic structure on a conveyor, it is collected into a coil shape by a converging device at a temperature range of 200 to 300°C, and gradually It is characterized in that it is cooled and self-tempered, then reheated to 400-600°C for tempering treatment, and then subjected to cold drawing with an area reduction of 10% or less to obtain a high-tensile wire rod with the desired tensile strength. That is. Next, the reasons for limiting the components of the present invention will be described.
C is added to give steel the necessary strength and hardenability, but if the amount of C is less than 0.20%, it will not be possible to obtain a tensile strength of 140 kg/mm 2 or more after blast cooling;
If the amount exceeds 0.40%, it is possible to obtain a tensile strength of 140 Kg/mm 2 or more, but workability and spot weldability are significantly deteriorated, which is not preferable. Si is an element effective in improving hardenability, strength, and toughness, but if the Si content is less than 0.20%, the effect is small, and if the Si content exceeds 1.50%, the ductility deteriorates, which is not preferable. Mn is an element that improves hardenability, but Mn
If the amount is less than 0.70%, no improvement in hardenability can be expected, and on the other hand, since the wire rod diameter (usually 5.5 to 11 mmφ) is small, Mn
Sufficient hardenability can be obtained without adding more than 2.50%. Cr, like Mn, is an element that improves hardenability, but if the amount of Cr is less than 0.10%, the hardenability effect is small;
Even if the amount of Cr does not exceed 1.50%, sufficient hardenability can be obtained for the same reason as with Mn. Like Mn, B is an element that improves hardenability, but if the amount of B is less than 0.0002%, no effect on hardenability can be expected, and even if the amount of B exceeds 0.005%, an even greater effect on hardenability can be expected. I can't get it. SolAl is an effective element for improving workability, but
If the amount of SolAl exceeds 0.060%, workability will deteriorate, which is not preferable. On the other hand, Ti: 0.05-0.15%, V: 0.03-0.08%,
Nb: The three elements of 0.02 to 0.08% are effective elements for suppressing tempering softening, but below the lower limit of each element, the effect of suppressing tempering softening cannot be expected, and when the upper limit of each element is exceeded, This is because the effect of suppressing back softening is saturated. Next, the reason why the forced cooling temperature after hot rolling is set to 500 to 700°C in the present invention will be explained. In other words, the supercooled austenitizing temperature is 500 to 700
℃ was chosen because theoretically it is possible to obtain a martensitic structure on the conveyor even if the material is cooled to a temperature of 700℃ or higher, but as the cooling start temperature increases, the blast time will inevitably decrease. Therefore, with a cooling rate of about 7°C/sec, there is a practical limit to the length of the conveyor, so the conveyor is focused by the focusing device in the next process before the martensitic transformation is completed, so the conveyor is partially focused. This is because a bainite structure occurs and the intended purpose cannot be achieved. On the other hand, the lower limit forced cooling temperature was set at 500°C because in actual rolling operations, it is difficult to cool the steel to a lower temperature within a very short time immediately after rolling. The reason why the blast cooling rate is set to 7° C./sec or more is because if the cooling rate is less than 7° C./sec, bainite structure, ferrite structure, etc. will occur, resulting in an incompletely quenched structure, which is not preferable. On the other hand, the appropriate temperature of the wire is 200 to 300°C when it is formed into a coil in a converging device after being cooled by air blast. When the wire is bundled using a bundler in this temperature range and slowly cooled, self-tempering is also performed in parallel, resulting in a tempered martensitic structure, which improves toughness and prevents cracking during winding or placement. be able to. The reason why the tempering temperature is set to 400 to 600°C is that if it is less than 400°C, it will become a blue brittle region and the strength variation will increase, and if it exceeds 600°C, the strength will decrease significantly, which is not preferable. The reason why the area reduction rate is set to 10% or less is that if it exceeds 10%, the yield ratio and proportionality limit will drop significantly, which is not preferable. Next, examples of the present invention will be described. A steel having the chemical composition of the steel of the present invention shown in Table 1 was used as a test material.
【表】
これらの鋼を用い1150〜1200℃にて鋼片を加熱
し、加熱後連続式圧延機にて10.3mmφに圧延を行
つた。この時の圧延開始温度は1150〜1250℃で仕
上温度は900〜950℃であり、その後直ちに強制冷
却設備にて水冷により550℃、600℃及び650℃に
急冷した後レーイングコーンによりリング状とし
コンベア上に展開し0.4ｍ／secの速度でコンベア
上を移動させた。この時コンベア上の線材を上部
及び下部より衝風により冷却速度10℃／secにて
冷却を行つた。尚コンベア長さは40ｍであり冷却
時間は約100秒であつた。次いで集中装置におい
てコイル状に集束した。この時の線材温度は230
〜280℃で該温度にてセルフテンパーを行つた後
各試料数の採取を行つた。この時の機械的性質を
第２表に示す。
その後、焼戻し処理として、500℃×２時間加
熱后空冷にて常温まで冷却を行い、その後減面率
７％の引抜加工を行い9.9mmφの伸線となした後
各試料数の採取を行つた。こうして得られた線材
の機械的性質を第２表に示す。[Table] Using these steels, steel slabs were heated at 1150 to 1200°C, and after heating, they were rolled to 10.3 mmφ using a continuous rolling mill. The rolling start temperature at this time is 1150-1250℃, and the finishing temperature is 900-950℃.After that, it is immediately cooled to 550℃, 600℃ and 650℃ using forced cooling equipment, and then rolled into a ring shape using a laying cone. It was spread on a conveyor and moved on the conveyor at a speed of 0.4 m/sec. At this time, the wire rod on the conveyor was cooled from the top and bottom by blast air at a cooling rate of 10° C./sec. The length of the conveyor was 40 m, and the cooling time was approximately 100 seconds. It was then focused into a coil in a concentrator. The wire temperature at this time is 230
After self-tempering at ~280°C, a number of samples were taken. The mechanical properties at this time are shown in Table 2. Thereafter, as a tempering treatment, the wire was heated at 500°C for 2 hours and then cooled to room temperature by air cooling, after which it was drawn with an area reduction rate of 7% and drawn into a wire of 9.9 mmφ, after which each number of samples was collected. . The mechanical properties of the wire thus obtained are shown in Table 2.
【表】
第２表で判る如く、本発明鋼の引張強度及び強
度バラツキについては従来鋼と同等の機械的性質
を有し、又絞り値については従来鋼よりも優れて
いる。
次に第１表に示す本発明鋼のＡ，Ｃ，Ｆ，Ｋの
４鋼種を、上記実施例と同様の圧延条件及び強制
冷却、衝風冷却、セルフテンパーを施した後の線
材を用い焼戻し温度を、300℃、350℃、400℃、
450℃、480℃、500℃、550℃、600℃、650℃、
700℃に変え、それぞれ２時間加熱の焼戻しを施
し引張強度を調べた。その結果を第１図に示す。
第１図で判る如く600℃以下の焼戻し温度では、
焼戻し処理後における線材の引張強度の下限値で
ある80Kg／mm2以上あり、600℃を越えると引張強
度の低下が大きくなつていることが判る。
更に上記供試材Ｋを用い、焼戻し温度480℃×
２時間加熱を行つた後、減面率を５％、10％、15
％、20％にそれぞれ変えて引抜加工を行つたもの
と、焼戻し温度600℃×２時間加熱を行つた後、
減面率を５％、10％、15％、20％にそれぞれ変え
て引抜加工を行つた時の引張強度と降伏比との関
係を第２図に示す。
第２図で判る如く、減面率が大きくなるにした
がい引張強度は上昇する。たとえば減面率10％で
は10〜12Kg／mm2の引張強度の上昇があり、一方降
伏比については、減面率５％以下では１〜３％の
降伏比が向上し、減面率５％を越えると少しずつ
降伏比が低下し、特に減面率10％を越えると降伏
比の低下が大きくなり６〜７％の降伏比の低下が
起きる。
たとえば１例として本発明鋼の供試材Ｋの圧延
及び強制冷却、衝風冷却、セルフテンパーを行つ
た後の線材の引張強度は165Kg／mm2（平均値）あ
り、該線材を焼戻し温度480℃×２時間加熱を施
したこの時の焼戻し後の引張強度は113Kg／mm2
（平均値）に低下し、該強度の線材を減面率５％
にて引抜加工を施した時の引張強度は119Kg／mm2
（引抜加工による強度上昇は６Kg／mm2）で、降伏
比は95％であつた。又減面率を10％に変えて引抜
加工を施した時の引張強度は124Kg／mm2（引抜加
工による強度上昇は11Kg／mm2）で降伏比は93％で
あつた。
一方焼戻し温度600℃×２時間加熱を施した。
この時の焼戻し後の引張強度は95Kg／mm2（平均
値）に低下し該強度の線材を減面率５％にて引抜
加工を施した時の引張強度は103Kg／mm2（引抜加
工による強度上昇は８Kg／mm2）で、降伏比は93％
であつた。又減面率を10％に変えて引抜加工を施
した時の、引張強度は106Kg／mm2（引抜加工によ
る強度上昇は11Kg／mm2）で、降伏比は91％であつ
た。上記のように焼戻し温度480℃及び600℃と、
減面率５％及び10％の引抜加工を組み合わせる事
により、引張強度103Kg／mm2、106Kg／mm2、119
Kg／mm2、124Kg／mm2の高張力線材を得ることがで
きた。
以上の説用で明らかなように、本発明法によれ
ば特定の成分の鋼を、圧延後冷却を行い、更に焼
戻し処理と適当な減面率の冷間引抜きとを組み合
せる事により従来と同等の引張強度を有し、強度
バラツキも少なく従来よりも優れた絞り性を有し
た引張強度90〜140Kg／mm2の範囲のPC鋼線、コン
クリートヒユーム管等の高張力線材を任意に製造
することができ、更に加工工程も従来法に比べ再
加熱の焼入工程が省略されており、エネルギー節
減の上でも大きな効果が得られた。[Table] As can be seen from Table 2, the steel of the present invention has mechanical properties equivalent to conventional steel in terms of tensile strength and strength variation, and is superior to conventional steel in terms of reduction of area. Next, four steel types of the present invention steels A, C, F, and K shown in Table 1 were tempered using the same rolling conditions as in the above example and the wire rods that had been subjected to forced cooling, blast cooling, and self-tempering. Temperature: 300℃, 350℃, 400℃,
450℃, 480℃, 500℃, 550℃, 600℃, 650℃,
The temperature was changed to 700°C, and each piece was heated and tempered for 2 hours, and the tensile strength was examined. The results are shown in FIG. As can be seen in Figure 1, at tempering temperatures below 600℃,
It can be seen that the lower limit of the tensile strength of the wire after tempering treatment is 80 kg/mm 2 or more, and that the tensile strength decreases significantly when the temperature exceeds 600°C. Furthermore, using the above sample material K, the tempering temperature was 480℃×
After heating for 2 hours, the area reduction rate was changed to 5%, 10%, 15
% and 20%, respectively, and after heating at a tempering temperature of 600℃ for 2 hours,
Figure 2 shows the relationship between tensile strength and yield ratio when drawing was performed with the area reduction ratio changed to 5%, 10%, 15%, and 20%. As can be seen from FIG. 2, as the area reduction rate increases, the tensile strength increases. For example, when the area reduction rate is 10%, the tensile strength increases by 10 to 12 Kg/mm 2 , while when the area reduction rate is 5% or less, the yield ratio increases by 1 to 3%, and when the area reduction rate is 5%. When the area reduction ratio exceeds 10%, the yield ratio gradually decreases, and especially when the area reduction ratio exceeds 10%, the yield ratio decreases significantly, and the yield ratio decreases by 6 to 7%. For example, as an example, the tensile strength of the wire rod after rolling, forced cooling, blast cooling, and self-tempering of test material K of the steel of the present invention is 165 Kg/mm 2 (average value), and the wire rod is tempered at a temperature of 480 kg/mm 2 (average value). The tensile strength after tempering is 113Kg/mm 2 after heating for 2 hours at ℃.
(average value), and the area reduction rate is 5% for wire rods with this strength.
The tensile strength when subjected to drawing processing is 119Kg/mm 2
(The strength increase due to drawing was 6 kg/mm 2 ), and the yield ratio was 95%. Further, when the area reduction rate was changed to 10% and drawing was performed, the tensile strength was 124 Kg/mm 2 (strength increase by drawing was 11 Kg/mm 2 ) and the yield ratio was 93%. On the other hand, heating was performed at a tempering temperature of 600°C for 2 hours.
At this time, the tensile strength after tempering decreased to 95Kg/mm 2 (average value), and when a wire rod with this strength was subjected to drawing with an area reduction rate of 5%, the tensile strength was 103Kg/mm 2 (due to drawing The strength increase is 8Kg/mm 2 ) and the yield ratio is 93%.
It was hot. When drawing was performed with the area reduction rate changed to 10%, the tensile strength was 106 Kg/mm 2 (strength increase by drawing was 11 Kg/mm 2 ) and the yield ratio was 91%. Tempering temperature 480℃ and 600℃ as above,
By combining drawing processes with area reduction rates of 5% and 10%, tensile strength of 103Kg/mm 2 , 106Kg/mm 2 , 119
We were able to obtain high tensile strength wire rods of Kg/mm 2 and 124 Kg/mm 2 . As is clear from the above explanation, according to the method of the present invention, steel with a specific composition is cooled after rolling, and is further combined with tempering treatment and cold drawing with an appropriate area reduction. We can optionally manufacture high-tensile wire rods such as PC steel wires and concrete fume pipes with a tensile strength range of 90 to 140 Kg/ mm2 that have the same tensile strength, less strength variation, and better drawability than conventional ones. Furthermore, compared to the conventional method, the reheating and quenching process was omitted, resulting in a significant energy saving effect.
第１図は焼戻し温度と引張強度との関係を示す
図、第２図は冷間引抜加工（減面率）と引張強度
及び降伏比との関係を示す図である。
FIG. 1 is a diagram showing the relationship between tempering temperature and tensile strength, and FIG. 2 is a diagram showing the relationship between cold drawing (area reduction ratio), tensile strength, and yield ratio.
Claims (1)
0.70〜2.50％、Cr：0.10〜1.50％、Ｂ：0.0002〜
0.005％、Sol.Al0.060％以下、残部はFe及び不可
避的不純物からなる鋼を、熱間圧延后直ちに500
〜700℃に強制冷却し、過冷オーステナイトの状
態でコンベア上に連続したリング状となして展開
し、衝風によつて７℃／Sec以上の冷却速度で冷
却してコンベア上において線材全体をマルテンサ
イト組織となした後、200〜300℃の温度範囲でコ
イル状に集束し徐冷してセルフテンパーを行い、
400〜600℃に再加熱して焼戻し処理を行つた後、
減面率10％以下の冷間引抜加工を施すことを特徴
とする高張線材の製造方法。 ２ Ｃ：0.20〜0.40％、Si：0.20〜1.50％、Mn：
0.70〜2.50％、Cr：0.10〜1.50％、Ｂ：0.0002〜
0.005％、SolAl：0.060％以下に更にTi：0.05〜
0.15％、Ｖ：0.03〜0.08％及びNb：0.02〜0.08％
のいずれか１種又は２種以上を含有させ、残部
Fe及び不可避的不純物からなる鋼を、熱間圧延
後、直ちに500〜700℃に強制冷却し、過冷オース
テナイトの状態でコンベア上に連続したリング状
となして展開し、衝風によつて７℃／Sec以上の
冷却速度で冷却してコンベア上において線材全体
をマルテンサイト組織となした後、200〜300℃の
温度範囲でコイル状に集束し徐冷してセルフテン
パーを行い、その後400〜600℃に再加熱して焼戻
し処理を行つた後、減面率10％以下の冷間引抜加
工を施すことを特徴とする高張力線材の製造方
法。[Claims] 1 C: 0.20-0.40%, Si: 0.20-1.50%, Mn:
0.70~2.50%, Cr: 0.10~1.50%, B: 0.0002~
0.005%, Sol.Al 0.060% or less, the balance being Fe and unavoidable impurities. Immediately after hot rolling, the steel is
The wire is forcedly cooled to ~700°C, and the supercooled austenite is rolled out in a continuous ring shape on a conveyor.The wire is then cooled by blast air at a cooling rate of 7°C/Sec or more, and the entire wire is placed on the conveyor. After forming a martensitic structure, self-tempering is performed by focusing it into a coil shape at a temperature range of 200 to 300℃ and slowly cooling it.
After being reheated to 400-600℃ and tempered,
A method for producing a high tensile wire rod, characterized by performing cold drawing with an area reduction rate of 10% or less. 2 C: 0.20-0.40%, Si: 0.20-1.50%, Mn:
0.70~2.50%, Cr: 0.10~1.50%, B: 0.0002~
0.005%, SolAl: 0.060% or less, and Ti: 0.05~
0.15%, V: 0.03-0.08% and Nb: 0.02-0.08%
Contain one or more of the following, and the remainder
After hot rolling, steel consisting of Fe and unavoidable impurities is immediately forcedly cooled to 500 to 700°C, rolled out in the form of a continuous ring on a conveyor in the state of supercooled austenite, and then blasted with air to form a continuous ring. After cooling the wire at a cooling rate of ℃/Sec or higher to make the entire wire into a martensitic structure on a conveyor, it is focused into a coil shape at a temperature range of 200 to 300℃ and slowly cooled to perform self-tempering. A method for producing high-tensile wire rods, which comprises reheating to 600°C and tempering, followed by cold drawing with an area reduction of 10% or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2327080A JPS56119728A (en) | 1980-02-25 | 1980-02-25 | Manufacture of high tensile wire rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2327080A JPS56119728A (en) | 1980-02-25 | 1980-02-25 | Manufacture of high tensile wire rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56119728A JPS56119728A (en) | 1981-09-19 |
| JPS6358891B2 true JPS6358891B2 (en) | 1988-11-17 |
Family
ID=12105904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2327080A Granted JPS56119728A (en) | 1980-02-25 | 1980-02-25 | Manufacture of high tensile wire rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56119728A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0421182U (en) * | 1990-06-08 | 1992-02-21 |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57126913A (en) * | 1981-01-27 | 1982-08-06 | Kobe Steel Ltd | Production of high-toughness high-strength wire or rod steel |
| JPS6013029A (en) * | 1983-07-01 | 1985-01-23 | Kawasaki Steel Corp | Production of high-tension steel bar material |
| JP2698374B2 (en) * | 1988-05-26 | 1998-01-19 | 川崎製鉄株式会社 | Method of manufacturing high-strength PC steel rod |
| US4938811A (en) * | 1988-07-15 | 1990-07-03 | Sumitomo Electric Industries, Ltd. | Steel wire for a spring and method for the production thereof |
| DE19962801A1 (en) * | 1999-12-23 | 2001-06-28 | Sms Demag Ag | Process for heat treating wire |
| CN103866195B (en) * | 2012-12-14 | 2016-08-03 | 中国兵器科学研究院宁波分院 | Carbon and low-alloy boron-containing structural steel and heat treatment method in one |
| CN107254635B (en) * | 2017-06-26 | 2019-02-19 | 邢台钢铁有限责任公司 | It is a kind of to exempt from annealed alloy steel wire rod and its production method with excellent drawing property |
| JP7091163B2 (en) * | 2018-06-27 | 2022-06-27 | 日本製鉄株式会社 | PC steel rod |
-
1980
- 1980-02-25 JP JP2327080A patent/JPS56119728A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0421182U (en) * | 1990-06-08 | 1992-02-21 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56119728A (en) | 1981-09-19 |
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