JPS6214008B2 - - Google Patents
Info
- Publication number
- JPS6214008B2 JPS6214008B2 JP11414781A JP11414781A JPS6214008B2 JP S6214008 B2 JPS6214008 B2 JP S6214008B2 JP 11414781 A JP11414781 A JP 11414781A JP 11414781 A JP11414781 A JP 11414781A JP S6214008 B2 JPS6214008 B2 JP S6214008B2
- Authority
- JP
- Japan
- Prior art keywords
- wire
- gas
- decarburization
- heat treatment
- dew point
- 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
- 238000010438 heat treatment Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 11
- 230000007935 neutral effect Effects 0.000 claims description 7
- 229910000831 Steel Inorganic materials 0.000 claims description 6
- 239000010959 steel Substances 0.000 claims description 6
- 229910001566 austenite Inorganic materials 0.000 claims description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims 1
- 239000007789 gas Substances 0.000 description 23
- 238000005261 decarburization Methods 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910000677 High-carbon steel Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- DYRBFMPPJATHRF-UHFFFAOYSA-N chromium silicon Chemical compound [Si].[Cr] DYRBFMPPJATHRF-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
Description
【発明の詳細な説明】
この発明は線材の熱処理方法、とくに炭素を
0.4％以上含む高炭素鋼線材の熱処理方法に関す
るものである。[Detailed Description of the Invention] This invention relates to a method for heat treatment of wire rods, especially carbon treatment.
This relates to a heat treatment method for high carbon steel wire containing 0.4% or more.
オイルテンパー線やピアノ線等は炭素含有量が
高く熱処理工程において脱炭をおこしがちである
が、この表面脱炭は最終製品の表面硬度を低下さ
せ、バネなどにおける最も重要な特性である疲労
特性を大幅に低下させる。特に高級バネ用線とし
て使用されるシリコンクロム鋼ではシリコン含有
量が高いため脱炭をおこしやすく、この鋼種では
完全に脱炭なしで熱処理を行なうことは至難であ
る。従来、高炭素鋼用熱処理として一般に行なわ
れているのは、炉内雰囲気として空燃比を調整し
た燃焼空気、RXガス、DXガスを用いる方法であ
るが、特に脱炭しやすい鋼のばあいは炉内の温度
バランスやCO／CO2比率の変動あるいは炉気中
露点の変動などのために完全に脱炭を防止するこ
とは困難であつた。また窒素ガスのような中性ガ
ス中で間接的に加熱して熱処理を行なう方法も行
なわれているが、実際には完全な中性ガス雰囲気
を維持することはできないために脱炭が起ること
は避けられなかつた。 Oil-tempered wire, piano wire, etc. have a high carbon content and tend to decarburize during the heat treatment process, but this surface decarburization reduces the surface hardness of the final product, resulting in fatigue properties, which are the most important properties for springs, etc. significantly lowers In particular, silicon chromium steel used as wire for high-grade springs has a high silicon content and is therefore prone to decarburization, and it is extremely difficult to heat treat this type of steel without completely decarburizing it. Conventionally, the commonly used heat treatment method for high carbon steel is to use combustion air, RX gas, or DX gas with an adjusted air-fuel ratio as the furnace atmosphere. It has been difficult to completely prevent decarburization due to changes in the temperature balance in the furnace, the CO/CO 2 ratio, and the dew point in the furnace air. Heat treatment is also performed by indirect heating in a neutral gas such as nitrogen gas, but in practice decarburization occurs because it is not possible to maintain a complete neutral gas atmosphere. It was inevitable.
この発明はこのような従来の欠点の解決のため
になされたものであり、高炭素鋼線材を表面の脱
炭を生じさせることなく熱処理する方法を提供す
るものである。すなわち、この発明は実質上スケ
ール、赤錆、脱炭層等のない表面を有する鋼線材
を熱処理する方法において、線材表面を100〜570
℃の範囲内で予備加熱した後、露点―10℃以下の
中性ガス雰囲気中もしくは還元性ガス雰囲気中で
加熱オーステナイト化後冷却するようにしたもの
である。 The present invention has been made to solve these conventional drawbacks, and provides a method for heat treating high carbon steel wire without causing surface decarburization. That is, the present invention provides a method for heat treating a steel wire having a surface substantially free of scale, red rust, decarburized layer, etc.
After preheating within a temperature range of -10°C, the material is heated to austenite in a neutral gas atmosphere or reducing gas atmosphere with a dew point of -10°C or lower, and then cooled.
オーステナイト化加熱の際の雰囲気ガスとして
中性ガスを用いても、このガス中に不純物が含ま
れていたり、ガス供給前に存在した大気雰囲気成
分が一部残留していたり、あるいは線材とともに
水分や大気成分が持ち込まれたりすることによ
り、脱炭を起すに足るCO2ガス、H2Oなどが雰囲
気中に含まれることになる。脱炭反応は主に
Ｃ（inγ―Fe）＋CO2→2CO ……(1)
の反応によつて起り、また
Ｃ（inγ―Fe）＋1/2O2→CO ……(2)
Ｃ（inγ―Fe）＋O2→CO2 ……(3)
Ｃ（inγ―Fe）＋2H2→CH4 ……(4)
の反応によつても起る。なお、雰囲気ガス中に水
分を含むと
CO＋H2OCO2＋H2 ……(5)
の水性ガス反応の平衡により、高温ではCO2が増
加するため脱炭は上記(1)式に従つて大幅に促進さ
れる。このため雰囲気中の水分（露点）の管理が
重要となる。そこでこの発明ではそれ自体では脱
炭を生じさせないガスとして露点―10℃以下のガ
スを用い、さらに被処理線材が水分等を持ち込む
のを防止するために予備加熱を行なうようにして
いる。すなわち、予備加熱を行なうことによつて
被処理線材の表面に附着、吸着している水分や微
量の油分等を蒸発、揮発させて雰囲気ガスが脱炭
性になることを防止し、また予備加熱を行なうこ
とによつて線材表面に緻密で薄いFe2O3の酸化膜
層を生成させ、雰囲気ガスと鋼材表面との脱炭反
応を防止するようにしている。このような作用効
果を生じさせるにはその温度範囲は100〜570℃が
必要であり、100℃以下では水分の蒸発が不完全
となり、また570℃以上ではスケールの生成速度
が大きくかつ厚いFeO層が生じてしまう。 Even if a neutral gas is used as the atmospheric gas during austenitizing heating, the gas may contain impurities, some of the atmospheric components that existed before the gas supply may remain, or moisture may be present along with the wire. When atmospheric components are brought in, the atmosphere contains CO 2 gas, H 2 O, etc., which are sufficient to cause decarburization. The decarburization reaction mainly occurs due to the reaction of C(inγ-Fe) + CO 2 →2CO ...(1), and the reaction of C(inγ-Fe) + 1/2O 2 →CO ...(2) C(inγ- It also occurs due to the reaction of Fe) + O 2 → CO 2 ... (3) C (inγ-Fe) + 2H 2 → CH 4 ... (4). Note that when moisture is included in the atmospheric gas, due to the equilibrium of the water gas reaction CO + H 2 OCO 2 + H 2 ... (5), CO 2 increases at high temperatures, so decarburization is significantly reduced according to equation (1) above. promoted. For this reason, it is important to control the moisture (dew point) in the atmosphere. Therefore, in the present invention, a gas with a dew point of -10°C or less is used as a gas that does not cause decarburization by itself, and further, preheating is performed to prevent moisture and the like from being brought into the wire material to be treated. That is, by performing preheating, moisture and trace amounts of oil adhering to or adsorbed on the surface of the wire to be processed are evaporated and volatilized, thereby preventing the atmospheric gas from becoming decarburized. By doing this, a dense and thin Fe 2 O 3 oxide film layer is generated on the wire surface, thereby preventing a decarburization reaction between the atmospheric gas and the steel surface. In order to produce such effects, the temperature range needs to be between 100 and 570°C; below 100°C, moisture evaporation is incomplete, and above 570°C, scale formation is rapid and a thick FeO layer is formed. will occur.
上記中性ガスとしては、例えば窒素ガスまたは
アルゴンガスを用いればよく、また還元性ガスと
してはアンモニア分解ガスを用いればよい。 As the neutral gas, for example, nitrogen gas or argon gas may be used, and as the reducing gas, ammonia decomposition gas may be used.
実施例
Ｃ＝0.54％、Si：1.44％、Mn：0.72％、Cr：
0.65％（JIS.G3566、SWOSC―Ｖ）の線材（直径
7.5mm）を以下の方法で熱処理した。すなわち、
線材表面温度250℃に予備加熱し（この際の酸化
膜の色は黄褐色）、これを露点―60℃の窒素ガス
雰囲気の炉で900℃に加熱後溶融鉛浴中で冷却し
た。これによつて得られた線材の表面部近傍の組
織は、第１図に示すように、フエライト脱炭層は
なく、かつ部分脱炭もない。Example C=0.54%, Si: 1.44%, Mn: 0.72%, Cr:
0.65% (JIS.G3566, SWOSC-V) wire rod (diameter
7.5mm) was heat treated in the following manner. That is,
The wire was preheated to a surface temperature of 250°C (the color of the oxide film was yellowish brown), heated to 900°C in a nitrogen gas atmosphere furnace with a dew point of -60°C, and then cooled in a molten lead bath. As shown in FIG. 1, the structure near the surface of the wire thus obtained has no ferrite decarburized layer and no partial decarburization.
一方、上記と同成分の材料を予備加熱を行なわ
ずに上記オーステナイト化熱処理を行なつたとこ
ろ、第２図に示すような組識になり、深さ0.15mm
の脱炭層が生じた。 On the other hand, when a material with the same composition as above was subjected to the above austenitizing heat treatment without preheating, the structure became as shown in Figure 2, with a depth of 0.15 mm.
A decarburized layer was formed.
また、上記両方法によつて得られた線材をそれ
ぞれ直径４mmの線材に伸線加工した後オイルテン
パー処理し、その硬度分布を見ると第３図に示す
ようになつた。すなわち、曲線１は予備加熱を行
なつたもの（本発明品）、曲線２は予備加熱を行
なわなかつたもの（従来品）の硬度分布を示し、
これより明らかなように従来法によるものでは表
面脱炭に起因する表面部の硬度の低下が認められ
るが、本発明によるものでは表面部まで硬度分布
は均一である。 Further, the wire rods obtained by both of the above methods were each drawn into wire rods with a diameter of 4 mm, and then subjected to oil tempering treatment, and the hardness distribution thereof was as shown in FIG. 3. That is, curve 1 shows the hardness distribution of the product that was preheated (product of the present invention), curve 2 shows the hardness distribution of the product that was not preheated (conventional product),
As is clear from this, in the case of the conventional method, there is a decrease in hardness at the surface due to surface decarburization, but in the case of the method of the present invention, the hardness distribution is uniform up to the surface.
また上記材料について上記予備加熱後雰囲気ガ
スとして露点―15℃のクラツクドアンモニアを用
いて900℃で加熱したばあいも脱炭は認められず
硬度分布も表面部まで均一であつた。さらに、
Ｃ：0.72％、Si：0.22％、Mn：0.69％、Cr：0.01
％（JIS.G3502.SWRS.72B）の線材（直径7.5
mm）についても上記熱処理による比較を行なつた
が結果はほぼ同じであつた。 Further, when the above material was heated at 900°C using cracked ammonia with a dew point of -15°C as the atmospheric gas after the above preheating, no decarburization was observed and the hardness distribution was uniform all the way to the surface. moreover,
C: 0.72%, Si: 0.22%, Mn: 0.69%, Cr: 0.01
% (JIS.G3502.SWRS.72B) wire rod (diameter 7.5
mm) was also compared using the heat treatment described above, and the results were almost the same.
以上説明したように、この発明は加熱オーステ
ナイト化処理の際の脱炭を防止するために、特定
の中性ガスを用いるとともに予備加熱を行なうよ
うにしたものであり、線材表面の脱炭は完全に防
止できて硬度分布も均一化されるとともに疲労限
も向上でき、品質のすぐれた線材を得ることがで
きるものである。なお、この発明は高炭素高マン
ガン非磁性鋼や過共析鋼の熱処理にも適用可能で
ある。 As explained above, this invention uses a specific neutral gas and performs preheating in order to prevent decarburization during heated austenitizing treatment, and the wire surface is completely decarburized. It is possible to prevent this from occurring, to make the hardness distribution uniform, and to improve the fatigue limit, making it possible to obtain a wire rod of excellent quality. Note that the present invention is also applicable to heat treatment of high carbon, high manganese nonmagnetic steel and hypereutectoid steel.
第１図はこの発明の方法によつて得られた線材
の組織写真、第２図は従来法による組織写真、第
３図は第１図および第２図の線材の硬度分布図で
ある。
１……本発明による線材の硬度分布、２……従
来法による線材の硬度分布。
FIG. 1 is a photograph of the structure of the wire rod obtained by the method of the present invention, FIG. 2 is a photograph of the structure of the wire rod obtained by the conventional method, and FIG. 3 is a hardness distribution diagram of the wire rods shown in FIGS. 1 and 2. 1... Hardness distribution of the wire rod according to the present invention, 2... Hardness distribution of the wire rod according to the conventional method.
Claims (1)
を有する鋼線材を熱処理する方法において、線材
表面を100〜570℃の範囲内で予備加熱した後、露
点―10℃以下の中性ガス雰囲気中もしくは還元性
ガス雰囲気中で加熱オーステナイト化後冷却する
ことを特徴とする線材の熱処理方法。1 In a method of heat treating steel wire having a surface virtually free of scale, red rust, decarburized layer, etc., the wire surface is preheated within the range of 100 to 570°C, and then heated in a neutral gas atmosphere with a dew point of -10°C or less. Alternatively, a method for heat treatment of a wire rod characterized by heating it to austenite in a reducing gas atmosphere and then cooling it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11414781A JPS5816033A (en) | 1981-07-20 | 1981-07-20 | Heat treatment for wire rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11414781A JPS5816033A (en) | 1981-07-20 | 1981-07-20 | Heat treatment for wire rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5816033A JPS5816033A (en) | 1983-01-29 |
| JPS6214008B2 true JPS6214008B2 (en) | 1987-03-31 |
Family
ID=14630318
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11414781A Granted JPS5816033A (en) | 1981-07-20 | 1981-07-20 | Heat treatment for wire rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5816033A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61163217A (en) * | 1985-01-08 | 1986-07-23 | Nippon Steel Corp | Method for annealing high cr steel wire rod |
| JPS62164818A (en) * | 1986-01-13 | 1987-07-21 | Honda Motor Co Ltd | Annealing method and direct firing type combustion furnace for annealing |
| JP2756003B2 (en) * | 1989-09-22 | 1998-05-25 | ブリヂストンメタルファ株式会社 | High strength steel cord excellent in corrosion fatigue resistance and method of manufacturing the same |
| CN102828017A (en) * | 2012-09-14 | 2012-12-19 | 南京钢铁股份有限公司 | Heating process of wire rod for tyre bead steel wire |
-
1981
- 1981-07-20 JP JP11414781A patent/JPS5816033A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5816033A (en) | 1983-01-29 |
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