JPS63130268A - Hot scarfing method - Google Patents

Abstract

PURPOSE:To prevent the generation of scarfing remainders of a corner part of a hot billet, and to improve the yield by increasing an oxygen flow rate of the end part of a nozzle unit corresponding to the size of the hot billet, at the time of bringing the hot billet to whole surface scarfing by a hot scarfing machine. CONSTITUTION:At the time of hot scarfing of a hot billet 1, a nozzle unit 10 is brought into contact with the hot billet 1 by a part of a shoe 2, and by sliding it, a prescribed interval is kept and the scarfing quantity is stabilized. In that case, oxygen for scarfing is jetted from a nozzle of a small diameter of an orifice plate 7 through a head 5 and a baffle plate 6 from a manifold 4 within a range corresponding to width of the hot billet 1 by an oxygen piston 3. In said nozzle unit 10, the oxygen jet quantity of both end parts is increased by providing a diameter difference on both end parts and the center part of said baffle plate 6. In such a way, the generation of scarfing remainders of a corner part whose temperature is apt to drop is prevented, surplus scarfing is made unnecessary, and the yield is improved.

Description

【発明の詳細な説明】 ［産業上の利用分野コ 本発明は熱鋼片をホットスカーフマシンによって全面溶
削する時、角部の溶削残り防止を可能とした熱間溶削方
法に関するものである。[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a hot cutting method that makes it possible to prevent uncut corners from remaining when a heated steel billet is entirely cut by a hot scarf machine. be.

［従来の技術コ 熱鋼片のホットスカーフマシンによる全面溶削は上下面
及び両側面の溶削用火口ユニットを用いて行う。[Conventional technology The entire surface of a heated steel billet is melt-cut using a hot scarf machine using melt-cutting nozzle units on the top, bottom, and both sides.

火口ユニットからのガス噴出址は火ロユニット＋ｉ全長
にわたって均一になるようにしており、鋼種・温度など
熱鋼片の特性や所要の溶削深さによりガス圧や溶剤時の
熱鋼片通過スピードの設定値を変えているが、熱鋼片角
部の溶剤残りが見られる場合は，ガス圧を高くしたり、
熱鋼片通過スピードを下げたりして対抗するケースもあ
る。また特公昭５７−５６２２号のように熱鋼片角部専
用の火口ユニットを別に設置し、角部の溶削量の向上を
図るなどの例がある。The gas ejected area from the crater unit is made to be uniform over the entire length of the crater unit, and the speed at which the hot billet passes when using gas pressure and solvent is determined by the properties of the hot billet such as steel type and temperature, and the required cutting depth. If you are changing the setting value of the hot steel sheet, but if solvent remains on the corner of the hot steel piece, increase the gas pressure or
In some cases, countermeasures include lowering the speed at which the hot steel billet passes. In addition, as in Japanese Patent Publication No. 57-5622, there is an example of installing a separate crater unit exclusively for the corner of a hot steel piece to improve the amount of cutting at the corner.

これら従来の方法には以下に示す問題点がある。These conventional methods have the following problems.

第２図はホットスカーフマシンによる溶削前後の鋼材の
断面形状を示す図であるが、図により問題点を説明すれ
ば，溶削前の鋼材断面形状８に対し、溶削後の鋼材断面
形状９は、辺の溶削量に比較して角部の溶削量が小さく
、溶削残りが発生している事がわかる。これは角部の温
度低下などによるものであるが、この角部のみが溶削さ
れずに残存するため、ビレットなどの圧延製品において
、ヘゲやシーム疵が残存するなどの問題点があった。Figure 2 is a diagram showing the cross-sectional shape of a steel material before and after melt cutting with a hot scarf machine.To explain the problem with the figure, the cross-sectional shape of the steel material 8 before melt cutting is different from the cross-sectional shape of the steel material after melt cutting. In No. 9, the amount of cutting on the corners is smaller than the amount of cutting on the sides, and it can be seen that there is some remaining material left after cutting. This is due to a drop in temperature at the corners, but since only these corners remain without being melted, there are problems such as sagging and seam flaws remaining in rolled products such as billets. .

また高炭素鋼材においては、脱炭はバネなどの疲労寿命
を低下させる事から線材の重要な品質項目であるが、ビ
レットでの脱炭が高炭素鋼線材の部分的脱炭になるなど
の問題があった。溶剤残りの状況によっては、１ランク
溶剤址を上げるなどして対処するケースがあるが十分で
はなく、鋼片のグラインダー手入により角部の入念な手
入を必要とし、品質保証、コストの面で問題があった。In addition, in high carbon steel materials, decarburization is an important quality item for wire rods as it reduces the fatigue life of springs, etc. However, there are problems such as decarburization in billets resulting in partial decarburization of high carbon steel wire rods. was there. Depending on the situation with remaining solvent, there are cases where raising the solvent level by one rank is a solution, but this is not sufficient, and the corners need to be carefully cleaned by grinding the steel pieces, which is a problem in terms of quality assurance and cost. There was a problem.

［発明の目的コ 本発明はこれらの問題が生ずる原因となるところの熱細
片の角部の溶剤残り防止を可能とした熱間溶剤方法を堤
供するものである。[Object of the Invention] The present invention provides a hot solvent method that makes it possible to prevent solvent from remaining at the corners of hot strips, which is the cause of these problems.

本発明は熱鋼片をホットスカーフマシンによって全面溶
剤する際、熱鋼片寸法に対応する火口ユニット端部の酸
素流量を増加させる熱間溶剤方法である。The present invention is a hot solvent method for increasing the oxygen flow rate at the end of the nozzle unit corresponding to the size of the hot steel piece when the hot steel piece is completely solvent-treated by a hot scarf machine.

［問題点を解決するための手段、作用］第１図は本発明
法の１例の模式図で、熱鋼片の４面に配した火口ユニッ
トのうちの１ユニツトについてその断面を示した説明図
であり、以下第１図により本発明を説明すれば、熱間溶
剤時、火口ユニットは熱鋼片１にシュー２の部分で接触
しスライドして一定間隔を保ち溶剤駄を安定させている
。[Means and effects for solving the problems] Figure 1 is a schematic diagram of one example of the method of the present invention, and is an explanation showing a cross section of one of the crater units arranged on the four sides of a hot steel piece. The present invention will be explained below with reference to FIG. 1. During hot solvent use, the nozzle unit contacts the hot steel piece 1 at the shoe 2 and slides to maintain a constant distance and stabilize the solvent drop. .

溶剤用酸素は酸素ピストン３による熱鋼片中に対応する
範囲においてマニホルド４からヘッド５．バッフルプレ
ート６を（例えば紙面の手前側及び裏側を）経てオリフ
ィスプレート７の直線に配置された小径のノズルから噴
出されるが、バッフルプレート６の両端部と中央部に径
差を設け、両端部を細くする事により、酸素の流れの抵
抗が小さくなり噴出斌が多くなる。径差を設ける部分の
長さ及び径差は熱鋼片の寸法・コーナーＲ等により決め
られる。　火口ユニット端部の酸素流量を増加させる方
法はバッフルプレートに径差を設ける方法の外に、専用
ユニットを設けることなく、同一火口ユニットの端部を
別の酸素系統にするなどの方法も可能である。Solvent oxygen is supplied from the manifold 4 to the head 5. It passes through the baffle plate 6 (for example, on the front side and the back side of the page) and is ejected from a small diameter nozzle arranged in a straight line on the orifice plate 7, but there is a diameter difference between both ends and the center of the baffle plate 6, By making it thinner, the resistance to the flow of oxygen becomes smaller and the number of blowouts increases. The length and diameter difference of the portion where the diameter difference is provided are determined by the dimensions of the hot steel piece, corner radius, etc. To increase the oxygen flow rate at the end of the crater unit, in addition to creating a diameter difference in the baffle plate, it is also possible to use a different oxygen system at the end of the same crater unit without installing a dedicated unit. be.

つぎに本発明を実施した場合と従来法での鋼片のグライ
ンダー手入能率の比較の１例を第１表に示す。第１表に
示す如く、本方案では角部溶剤残りを防止出来た事によ
り、手入能率は５０．９％と著しく向上した。Next, Table 1 shows an example of a comparison of the grinder maintenance efficiency of steel slabs when the present invention is implemented and the conventional method. As shown in Table 1, this method significantly improved the cleaning efficiency to 50.9% due to the prevention of solvent residue at the corners.

第　　　１　　　表 但し　　傘１　　（Ｃ）＝（Ａ）−（Ｂ）峠（Ｄ）＝（
Ｃ）／（Ｂ）ｘ１００％ また高炭素鋼線材の脱炭基準外れの発生率について本発
明を実施した場合と従来法との比較を第２表に示す。表
に示すごとく、本発明では角部溶剤残りを防ｆヒ出来た
事により、線材の部分脱炭による基準外れ発生率が減少
し、切り込み加工が不要となった。First Table However, Umbrella 1 (C) = (A) - (B) Pass (D) = (
C)/(B)x100% Furthermore, Table 2 shows a comparison between the case where the present invention is implemented and the conventional method regarding the incidence of deviation from the decarburization standard of high carbon steel wire rods. As shown in the table, in the present invention, since the residual solvent at the corners can be prevented from fraying, the incidence of deviation from the standard due to partial decarburization of the wire rod is reduced, and cutting is no longer necessary.

第　　　２　　　表 但し　−１（Ｃ）＝（Ａ）−（ロ） 傘２　　　（Ｄ）＝　　（（Ａ）−（Ｂ））　　／（Ａ
）Ｘ１００％［発明の効果］ 本発明は以上の説明の如く次のような効果がある。Table 2 Provided that -1 (C) = (A) - (B) Umbrella 2 (D) = ((A) - (B)) / (A
)X100% [Effects of the Invention] As explained above, the present invention has the following effects.

（１）溶剤斌が辺と角部が同程度に均一化されることか
ら余分に溶剤盪を増加させる必要がなくなり歩留が向上
する。(1) Since the solvent droplet is made uniform to the same extent on the sides and corners, there is no need to increase the solvent droplet, and the yield is improved.

（２）鋼片角部のヘゲ疵やシーム疵が減少する事からグ
ラインダー手入能率が著しく向上する。(2) The grinder maintenance efficiency is significantly improved since the number of sludge defects and seam defects on the corners of the steel billet is reduced.

（３）高炭素鋼材においては脱炭不良による切込加工量
が減少する。(3) In high carbon steel materials, the amount of cutting due to poor decarburization is reduced.

（４）品質が安定する。(4) Quality is stable.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明を示す火ｌ］ユニットの例の断面説明図
、第２図は従来法によるホットスカーフ前後の鋼材の断
面形状を示す図である。 ■・・・熱鋼片、２・・・シュー、３・・・酸素ピスト
ン、４・・・マニホルド、５・・・ヘッド、６・・・バ
ッフルプレート、７・・・オリフィスプレー１へ、８・
・・溶剤Ｍｆ鋼材断面形状、９・・・溶剤後鋼材断面形
状、１０・・・火口ユニット。 特許出願人　　新日本製鐵株式会社 日本スピング株式会社FIG. 1 is a cross-sectional explanatory diagram of an example of a hot scarf unit showing the present invention, and FIG. 2 is a diagram showing the cross-sectional shape of a steel material before and after a hot scarf according to a conventional method. ■... Hot steel piece, 2... Shoe, 3... Oxygen piston, 4... Manifold, 5... Head, 6... Baffle plate, 7... To orifice spray 1, 8・
... Solvent Mf steel material cross-sectional shape, 9... Steel material cross-sectional shape after solvent, 10... Crater unit. Patent applicant Nippon Steel Corporation Nippon Sping Co., Ltd.

Claims (1)

【特許請求の範囲】[Claims] 熱鋼片をホットスカーフマシンによって全面溶剤する際
、熱鋼片寸法に対応する火口ユニット端部の酸素流量を
増加させることによって熱鋼片角部の溶削残り防止を可
能とすることを特徴とする熱間溶削方法When a hot steel billet is entirely subjected to solvent treatment using a hot scarf machine, it is possible to prevent residual machining at the corners of the hot steel billet by increasing the oxygen flow rate at the end of the crater unit corresponding to the size of the hot steel billet. Hot cutting method