JPH01162786A - Method for pickling high strength austenitic stainless steel - Google Patents
Method for pickling high strength austenitic stainless steelInfo
- Publication number
- JPH01162786A JPH01162786A JP32133687A JP32133687A JPH01162786A JP H01162786 A JPH01162786 A JP H01162786A JP 32133687 A JP32133687 A JP 32133687A JP 32133687 A JP32133687 A JP 32133687A JP H01162786 A JPH01162786 A JP H01162786A
- Authority
- JP
- Japan
- Prior art keywords
- nitric
- acid
- treatment
- descaling
- immersion
- 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
- 229910000963 austenitic stainless steel Inorganic materials 0.000 title claims abstract description 13
- 238000000034 method Methods 0.000 title claims description 36
- 238000005554 pickling Methods 0.000 title claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 35
- 238000007654 immersion Methods 0.000 claims abstract description 30
- 150000003839 salts Chemical class 0.000 claims abstract description 24
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 20
- 238000005097 cold rolling Methods 0.000 claims abstract description 8
- 229960002050 hydrofluoric acid Drugs 0.000 claims description 35
- 238000005868 electrolysis reaction Methods 0.000 claims description 34
- 239000007788 liquid Substances 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 238000007598 dipping method Methods 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 abstract description 30
- 239000002253 acid Substances 0.000 abstract description 15
- 229910000831 Steel Inorganic materials 0.000 abstract description 14
- 239000010959 steel Substances 0.000 abstract description 14
- 230000007935 neutral effect Effects 0.000 abstract description 8
- 238000007670 refining Methods 0.000 abstract description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 15
- 239000000243 solution Substances 0.000 description 13
- 239000000523 sample Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000005096 rolling process Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000010960 commercial process Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 238000002203 pretreatment Methods 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 239000010960 cold rolled steel Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- CCJHDZZUWZIVJF-UHFFFAOYSA-N iodo nitrate Chemical compound [O-][N+](=O)OI CCJHDZZUWZIVJF-UHFFFAOYSA-N 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- JVJQPDTXIALXOG-UHFFFAOYSA-N nitryl fluoride Chemical compound [O-][N+](F)=O JVJQPDTXIALXOG-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/08—Iron or steel
- C23G1/086—Iron or steel solutions containing HF
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は冷間圧延後に低温域での熱処理を行い高強度化
をはかったオーステナイト系ステンレス鋼の酸洗方法に
関するものである。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pickling method for austenitic stainless steel, which is subjected to heat treatment in a low temperature range after cold rolling to increase its strength.
〈従来の技術〉
高強度オーステナイト系ステンレス鋼の製造法のひとつ
として加工硬化現象を利用する方法がよく用いられてい
る。この方法は熱延鋼帯を冷間圧延した後、約１０００
〜１１５０℃の固溶化熱処理および脱スケール処理を行
った後に圧延率５〜３０％程度の軽度の冷間圧延をほど
こして高強度を得る方法である。これは固溶化熱処理に
より完全に軟化した状態の材料を軽度の冷間圧延により
高強度化する方法であり、とくにｓｕｓ ３ｏｉａにつ
いて多用されている。以後この製造法を圧延ｇｌｌｆ法
と呼ぶ。<Prior Art> As one of the methods for manufacturing high-strength austenitic stainless steel, a method that utilizes work hardening phenomenon is often used. This method involves cold-rolling a hot-rolled steel strip and then
This is a method of obtaining high strength by performing solution heat treatment at ~1150°C and descaling treatment, and then applying mild cold rolling at a rolling reduction of about 5 to 30%. This is a method of increasing the strength of a material that has been completely softened by solution heat treatment by mild cold rolling, and is particularly frequently used for SUS 3OIA. Hereinafter, this manufacturing method will be referred to as the rolling gllf method.
一方、この調質圧延法に対し、製造工程の短縮と良好な
鋼板形状を得る製造法として特開昭６０−４３４２９号
の方法が提案されている。この方法は熱延鋼帯を製品厚
まで冷間圧延した後、７５０〜９５０℃の低温域の熱処
理を行って高強度を得る方法である。以後この方法を熱
処理調質法と呼ぶ。On the other hand, in contrast to this temper rolling method, a method has been proposed in JP-A-60-43429 as a manufacturing method that shortens the manufacturing process and provides a good steel sheet shape. This method is a method in which a hot rolled steel strip is cold rolled to a product thickness and then heat treated at a low temperature range of 750 to 950°C to obtain high strength. Hereinafter, this method will be referred to as the heat treatment and refining method.
調質圧延法における固溶化熱処理および熱処理調質法に
おける低温域の熱処理は通常酸化性雰圀気で行われ表面
に酸化スケールが形成されるので、熱処理に引続いて脱
スケール処理が行われる。Solution heat treatment in the temper rolling method and heat treatment in the low temperature range in the heat treatment temper method are usually performed in an oxidizing atmosphere and oxide scale is formed on the surface, so a descaling treatment is performed subsequent to the heat treatment.
オーステナイト系ステンレス冷延鋼板の脱スケール処理
は次に示す３種の方法で通常行われている。Descaling treatment of cold-rolled austenitic stainless steel sheets is usually carried out by the following three methods.
■硝酸電解または硫酸電解→硝弗酸浸漬■ソルト処理→
硝酸電解または硫酸電解→硝弗酸浸漬
■中性塩電解→硝弗゛酸浸漬
上記■〜■のプロセスにおいて、ソルト処理。■Nitric acid electrolysis or sulfuric acid electrolysis → Nitrofluoric acid immersion ■Salt treatment →
Nitric acid electrolysis or sulfuric acid electrolysis → nitric-fluoric acid immersion ■ Neutral salt electrolysis → nitric-fluoric acid immersion In the process of ① to ① above, salt treatment.
硝酸電解、硫酸電解、中性塩電解はいずれも後続の硝弗
酸浸漬の負荷を軽減させるための前処理であり、脱スケ
ールの主体は硝弗酸浸漬によっている。Nitric acid electrolysis, sulfuric acid electrolysis, and neutral salt electrolysis are all pretreatments to reduce the load of subsequent nitric-fluoric acid immersion, and descaling is mainly performed by nitric-fluoric acid immersion.
硝弗酸は硝酸と弗酸の混合水溶液であるが、オーステナ
イト系ステンレス鋼板の脱スケールに用いられる水溶液
の酸濃度は一般に硝酸濃度５％超えの５〜２０−ｔ％、
弗酸濃度０．５〜４ｗｔ％（以下単に％とする）である
。Nitrofluoric acid is a mixed aqueous solution of nitric acid and hydrofluoric acid, and the acid concentration of the aqueous solution used for descaling austenitic stainless steel sheets is generally 5 to 20-t%, with a nitric acid concentration exceeding 5%,
The hydrofluoric acid concentration is 0.5 to 4 wt% (hereinafter simply referred to as %).
１０００〜１１５０℃の固溶化熱処理後の脱スケールに
おいては前述の■〜■の脱スケールプロセスで迅速でか
つ表面仕上がり良好な脱スケールが可能であった。In descaling after solution heat treatment at 1,000 to 1,150°C, rapid descaling with a good surface finish was possible using the descaling processes (1) to (4) described above.
ところが熱処理調質法の低温域熱処理後の脱スケールに
おいては従来条件の■〜■の脱スケールプロセスでは脱
スケールが困難となり、脱スケール処理時間が長くなり
、かつ仕上がり表面にむらが生じやすいという問題点が
生じていた。However, in descaling after low-temperature heat treatment in the heat treatment and refining method, it is difficult to descale using the conventional descaling processes (1) to (3), the descaling process takes a long time, and the finished surface tends to be uneven. A dot had appeared.
〈発明が解決しようとする問題点〉
本発明の目的は数多くの利点を有する熱処理調質法の有
効活用をはかるため、低温域の熱処理後の脱スケールに
通した脱スケール条件を提案することである。<Problems to be Solved by the Invention> The purpose of the present invention is to propose descaling conditions for descaling after heat treatment in a low temperature range, in order to effectively utilize the heat treatment refining method, which has many advantages. be.
く問題点を解決するための手段〉
本発明は、冷間圧延後に９５０’Ｃ以下の低温域で熱処
理を施し高強度化したオーステナイト系ステンレス鋼を
、硝酸電解処理または硫酸電解処理後に、あるいはソル
ト処理の後の硝酸電解処理または硫酸電解処理後に、あ
るいは中性塩電解処理後に硝弗酸に浸漬して脱スケール
処理を行うに際し、前記浸漬用硝弗酸の液組成を＋ｖｏ
、： ２．５〜５．Ｏｗｔ％、 ＩＦ： ０．６〜
２．Ｏｗｔ％の範囲の水溶液とすることを特徴とする高
強度オーステナイト系ステンレス鋼の酸洗方法である。Means for Solving the Problems> The present invention provides austenitic stainless steel that has been heat-treated at a low temperature of 950'C or less after cold rolling to increase its strength, after nitric acid electrolytic treatment or sulfuric acid electrolytic treatment, or by salt treatment. When performing descaling treatment by immersion in nitric-fluoric acid after nitric acid electrolysis treatment or sulfuric acid electrolysis treatment after treatment, or after neutral salt electrolysis treatment, the liquid composition of the nitric-fluoric acid for immersion is +vo.
,: 2.5-5. Owt%, IF: 0.6~
2. This is a pickling method for high-strength austenitic stainless steel characterized by using an aqueous solution in the range of Owt%.
く作 用〉
本発明者らは前記目的達成のため、オーステナイト系ス
テンレス冷延鋼板に対し従来実施されている脱スケール
法の各プロセスにおける脱スケール作用と低温域熱処理
後の脱スケールが困難となる原因について調べ、以下の
ことを見出した。In order to achieve the above-mentioned objective, the present inventors discovered that the descaling effect in each process of the descaling method conventionally carried out on austenitic stainless steel cold rolled steel sheets and the descaling after low-temperature heat treatment are difficult. We investigated the cause and found the following.
硝弗酸浸漬前に行われる、ソルト処理、硫酸電解、硝酸
電解、中性塩電解のいずれもがその主な作用は酸化スケ
ールを改質して、後続の硝弗酸浸漬において酸液が酸化
スケール直下の地鉄まで浸透しやす（させることである
。The main effect of salt treatment, sulfuric acid electrolysis, nitric acid electrolysis, and neutral salt electrolysis performed before nitric-fluoric acid immersion is to modify the oxidized scale, so that the acid solution is oxidized during the subsequent nitric-fluoric acid immersion. It is easy to penetrate into the substructure directly below the scale.
この酸化スケールの改質作用は低温域熱処理で形成され
た酸化スケールに対しても、高温の固溶化熱処理で形成
された酸化スケールに対すると同等に有効に働いている
ことが判明した。It has been found that this oxidized scale reforming effect works equally effectively on the oxidized scale formed by low-temperature heat treatment as it does for the oxidized scale formed by high-temperature solution heat treatment.
一方硝弗酸漫漬の作用は酸化スケール直下の地鉄表層部
に形成されている脱Ｃｒ層（Ｃｒ欠乏層ともいう）を溶
解することにより酸化スケールを除去することであり、
硝弗酸はこの脱ＣｒＪｉを溶解するのに適した酸液とし
て利用されてきた。On the other hand, the action of nitrofluoric acid pickling is to remove oxide scale by dissolving the Cr-depleted layer (also called Cr-deficient layer) that is formed on the surface layer of the steel directly below the oxide scale.
Nitrofluoric acid has been used as an acid solution suitable for dissolving this CrJi removal.
因みに、脱ＣｒＮはステンレス鋼が酸化するｇ （ｒが
Ｆｅよりも優先酸化するために酸化スケール直下の地鉄
のＣｒ含有量が地鉄中心部のＣｒ含有量よりも低くなる
ために形成されるものである。Incidentally, de-CrN is formed when stainless steel oxidizes (g), which oxidizes more preferentially than Fe, so that the Cr content in the steel base immediately below the oxidation scale becomes lower than the Cr content in the center of the steel base. It is something.
高温で行われる固溶化熱処理の場合は酸化が十分に進み
、したがって脱ＣｒＦＪの形成も十分に行われるため、
硝弗酸による溶解作用が有効に働き脱スケールがすみや
かに行われる。In the case of solution heat treatment carried out at high temperatures, oxidation progresses sufficiently and therefore the formation of Cr-free FJ is also sufficiently carried out.
The dissolving action of nitric hydrofluoric acid works effectively and descaling is carried out quickly.
しかしながら低温域熱処理の場合は酸化が十分に進まず
、したがって脱ＣｒＮの形成が不十分となるため、硝弗
酸による溶解作用が有効に行われず、脱スケールが困難
となり、仕上がり表面にむらを住じやすくなると考えら
れる。However, in the case of low-temperature heat treatment, oxidation does not proceed sufficiently and the formation of CrN removal is therefore insufficient, so the dissolving action of nitric-fluoric acid is not effective, making descaling difficult and causing unevenness on the finished surface. This is thought to make it easier to understand.
本発明者らは脱ＣｒＪｉの形成が不十分な場合に酸化ス
ケール直下の地鉄表層部を溶解させるのに適した酸液の
条件を検討した結果、従来の領域とは異なった特定濃度
範囲の硝弗酸が通していることを見出した。またこの特
定濃度範囲の硝弗酸は通常行われる固溶化熱処理後の十
分に脱Ｃｒ層が形成されている場合には溶解力が劣り適
していないことも見出した。The present inventors investigated the conditions for acid solution suitable for dissolving the surface layer of the steel directly under the oxide scale when the formation of CrJi removal is insufficient. It was discovered that nitric fluoric acid passed through it. It has also been found that nitric-fluoric acid in this specific concentration range is not suitable because of its poor dissolving power when a sufficient Cr-free layer is formed after the usual solution heat treatment.
次に硝弗酸の濃度範囲の限定理由を第１図に基づいて説
明する。Next, the reason for limiting the concentration range of nitric hydrofluoric acid will be explained based on FIG.
！＋Ｎｏ、ｆｉ度が５．０％を越える領域Ｂは従来使用
されている濃度範囲を含む領域であるが、脱Ｃｒ層の形
成が不十分な場合は酸化スケール直下の地鉄の熔解力が
弱いため脱スケールに長時間を要する。! +No, region B where the fi degree exceeds 5.0% is a region that includes the conventionally used concentration range, but if the formation of the Cr-free layer is insufficient, the melting power of the base iron directly under the oxide scale is weak. Therefore, it takes a long time to descale.
）ＩＮＯ３濃度が２．５〜５％で、かつＨＦ濃度が０．
６〜２．０の領域Ａは本発明法の濃度範囲であり、脱Ｃ
ｒ層の形成が不十分な場合に酸化スケール直下の地鉄を
迅速に溶解する作用があるため、脱スケールが短時間で
可能となり、また仕上がり表面も均一性にすぐれたもの
となる。)INO3 concentration is 2.5-5% and HF concentration is 0.
Region A of 6 to 2.0 is the concentration range of the method of the present invention, and
When the r-layer is insufficiently formed, it has the effect of quickly dissolving the base iron directly under the oxide scale, so descaling can be done in a short time, and the finished surface also has excellent uniformity.
ｏＮｏｓｅ４度ｆＪ＜２．５〜５％テアッテも、ＨＦ濃
度が０．６％以下の領域Ｃの場合は溶解力が低下するた
め脱スケールに長時間を要し、逆に１ＩＦｉｆ１度が２
．０％を越える領域りの場合は溶解力が著しく強まり、
仕上がり表面が荒れて粗面となる。oNose 4 degrees fJ < 2.5-5% Teatte also takes a long time to descale when the HF concentration is in region C below 0.6%, as the dissolving power decreases;
．． In the area exceeding 0%, the dissolving power becomes significantly stronger,
The finished surface becomes rough and rough.
１（ｊ１０３濃度が２．５％以下の領域Ｅの場合は熔解
力が低下し脱スケールに長時間を要するようになる。1 (j) In the case of region E where the concentration of 103 is 2.5% or less, the melting power decreases and descaling takes a long time.
硝弗酸の負荷を軽減するため硝弗酸浸漬前に従来実施さ
れているソルト処理、硝酸電解、硫酸電解、中性塩電解
などの前処理は本発明法においても有効に作用するので
必要であり、それら個々の処理条件は従来と同一の条件
が本発明法においても適用できる。Pretreatments such as salt treatment, nitric acid electrolysis, sulfuric acid electrolysis, and neutral salt electrolysis, which are conventionally carried out before nitric-fluoric acid immersion in order to reduce the load of nitric-fluoric acid, are also effective in the method of the present invention and are therefore not necessary. The same processing conditions as in the conventional method can also be applied to the method of the present invention.
硝弗酸の液温は高い方が溶解力が強くなるが高くなりす
ぎるとＨＦの気化蒸発が激しくなるので室温〜７０℃の
範囲が通用されるが、５０〜６０“Ｃが最適である。The higher the liquid temperature of nitric-fluoric acid, the stronger the dissolving power will be, but if it becomes too high, the vaporization of HF will be intense, so a range of room temperature to 70°C is commonly used, but 50 to 60"C is optimal.
硝弗酸への浸漬時間は熱処理時間（主として板厚によっ
て決まる）および硝弗酸浸漬前の前処理の程度によって
異なるが、例えば板厚１．５ｍでソルト処理と硫酸電解
を行った場合は約１分間程度の硝弗酸浸漬で十分に脱ス
ケールが可能である。The immersion time in nitric-fluoric acid varies depending on the heat treatment time (mainly determined by the board thickness) and the degree of pretreatment before immersion in nitric-fluoric acid, but for example, when salt treatment and sulfuric acid electrolysis are performed on a board with a thickness of 1.5 m, approximately Sufficient descaling is possible by immersion in nitrofluoric acid for about 1 minute.
硝弗酸浸漬により脱スケール処理は完了するが、脱スケ
ール後の地鉄表面の不動態化をより強固にするため硝弗
酸浸漬に引続いて硝酸浸漬あるいは硝酸電解を随時付加
してもよい。Descaling treatment is completed by dipping in nitric-fluoric acid, but nitric acid dipping or nitric acid electrolysis may be added at any time following dipping in nitric-fluoric acid to further strengthen the passivation of the surface of the bare metal after descaling. .
〈実施例〉
実施例１
第１表に示す化学組成をもつ焼鈍および酸洗を行った板
厚４．０胴の熱延鋼帯を商用工程により板厚１．０調に
冷間圧延し、８３０℃，７０秒の低温域熱処理を行い、
脱スケール実験用供試材とした。<Examples> Example 1 A hot-rolled steel strip with a thickness of 4.0 that had been annealed and pickled and had the chemical composition shown in Table 1 was cold rolled to a thickness of 1.0 using a commercial process. Perform low-temperature heat treatment at 830°C for 70 seconds,
This was used as a sample material for descaling experiments.
供試材について、ソルト処理→硫酸電解→硝弗酸浸漬の
プロセスで脱スケール処理を行い、処理後の表面状況を
調べた。The sample materials were descaled using a process of salt treatment, sulfuric acid electrolysis, and nitrofluoric acid immersion, and the surface condition after treatment was investigated.
ソルト処理は４３０’Ｃ，３０秒浸漬、硫酸電解は濃度
５％、液温５０℃１電流密度１０Ａ／ｄｍ”、 アノ
ード２秒カソード２秒の一定条件とし、硝弗酸浸漬条件
を変化させた。The salt treatment was carried out at 430'C for 30 seconds, and the sulfuric acid electrolysis was carried out under the following conditions: concentration 5%, liquid temperature 50°C, current density 10 A/dm'', anode 2 seconds and cathode 2 seconds, and nitric hydrofluoric acid immersion conditions varied. .
得られた結果を第２表に示す。本発明の硝弗酸濃度範囲
にあるＮα３．Ｎα４．Ｎα５は６０秒以下の浸漬で良
好に脱スケールすることができた。一方、従来の硝弗酸
濃度範囲にある場合はＮα２のように６０秒の浸漬では
スケール残りが生じ、Ｎα１のように２４０秒の浸漬を
行うとスケールは除去されたが表面に色調むらを生じた
。The results obtained are shown in Table 2. Nα3 within the nitrofluoric acid concentration range of the present invention. Nα4. Nα5 could be successfully descaled by immersion for 60 seconds or less. On the other hand, when the concentration is within the conventional nitrofluoric acid concentration range, 60 seconds of immersion like Nα2 leaves scale residue, while 240 seconds of immersion like Nα1 removes the scale but causes uneven color tone on the surface. Ta.
実施例２
第１表に示す化学組成をもつ焼鈍および酸洗を行った板
厚４．０ｍｍ０熱延鋼帯を商用工程により板厚１．５鵬
に冷間圧延し、９００℃，１２０秒の低温域熱処理を行
い、脱スケール実験用供試材とした。Example 2 A hot-rolled steel strip with a thickness of 4.0 mm that had been annealed and pickled and had the chemical composition shown in Table 1 was cold rolled to a thickness of 1.5 mm by a commercial process, and then rolled at 900°C for 120 seconds. It was subjected to low temperature heat treatment and used as a sample material for descaling experiments.
供試材について、中性塩電解→硝弗酸浸漬のプロセスで
脱スケール処理を行い、処理後の表面状況を調べた。The sample materials were descaled using a process of neutral salt electrolysis and nitric fluoride immersion, and the surface condition after treatment was investigated.
中性塩電解は溶液濃度２０％Ｎａ２５Ｏｎ＋ 液温８５
℃１電流密度６Ａ／ｄｍ”、 カソード１５秒アノー
ド１５秒の一定条件とし、硝弗酸浸漬条件を変化させた
。For neutral salt electrolysis, the solution concentration is 20% Na25On+ and the liquid temperature is 85%.
℃ 1 current density 6 A/dm'', cathode 15 seconds anode 15 seconds, and nitric-fluoric acid immersion conditions were varied.
得られた結果を第３表に示す。硝弗酸濃度が本発明範囲
内にあるＮα８．Ｎα９は４０秒以下の浸漬で良好に脱
スケールしている。一方、従来の硝弗酸濃度範囲にある
場合はＮα７のように４０秒の浸漬ではスケール残りが
生じ、Ｎα１のように１２０秒の浸漬を行わないと良好
に脱スケールすることができなかった。The results obtained are shown in Table 3. Nα8. whose nitric hydrofluoric acid concentration is within the range of the present invention. Nα9 was successfully descaled by immersion for 40 seconds or less. On the other hand, when the concentration of nitric hydrofluoric acid is within the conventional nitric-fluoric acid concentration range, scale remains after 40 seconds of immersion as in Nα7, and good descaling could not be achieved unless immersed for 120 seconds as in Nα1.
実施例３
第１表に示す化学組成をもつ焼鈍および酸洗を行った板
厚４．０鴫の熱延鋼帯を商用工程により板厚１．０Ｍに
冷間圧延し、１１００℃１６０秒の固溶化熱処理を行い
、脱スケール実験用供試材とした。Example 3 A hot-rolled steel strip with a thickness of 4.0 mm that had been annealed and pickled and had the chemical composition shown in Table 1 was cold rolled to a thickness of 1.0 M using a commercial process, and then rolled at 1100°C for 160 seconds. It was subjected to solution heat treatment and used as a sample material for descaling experiments.
供試材についてソルト処理→硫酸電解→硝弗酸浸漬のプ
ロセスで脱スケール処理を行い、処理後の表面状況を調
べた。The sample materials were descaled using the process of salt treatment, sulfuric acid electrolysis, and nitric-fluoric acid immersion, and the surface condition after treatment was investigated.
ソルト処理および硫酸電解は実施例１と同一とし、硝弗
酸浸漬条件を変化させた。The salt treatment and sulfuric acid electrolysis were the same as in Example 1, but the nitric-fluoric acid immersion conditions were changed.
得られた結果を第４表に示す。The results obtained are shown in Table 4.
従来の硝弗酸濃度範囲にあるＮｏ、 １０は２０秒の浸
漬で良好に脱スケールすることができた。しかしながら
本発明の硝弗酸濃度範囲としたＮｏ、１１の例は２０秒
の浸漬でスケール残りを生した。すなわち１０００℃以
上で行われる固溶化熱処理後の脱スケールには適さない
ことが判る。No. 10, which is in the conventional nitric-fluoric acid concentration range, could be successfully descaled by immersion for 20 seconds. However, in Example No. 11, which had a nitric-fluoric acid concentration range of the present invention, scale remained after 20 seconds of immersion. That is, it is found that it is not suitable for descaling after solution heat treatment performed at 1000° C. or higher.
また実施例１の脱スケール実験用供試材に、前処理酸洗
条件を、次のように種々変えＨＮＯ３４％。In addition, the pretreatment pickling conditions for the sample material for the descaling experiment of Example 1 were varied as follows, and HNO was 34%.
ＨＦ １．０％で６０℃の硝弗酸水溶液に６０秒浸漬処
理したときの結果を第５表に示す。Table 5 shows the results of immersion treatment in a 60° C. nitric-fluoric acid aqueous solution containing 1.0% HF for 60 seconds.
硫酸電解処理条件
濃度７％、液温５０℃８電流密度１０Ａ／ｄｍ２゜アノ
ード５秒カソード５秒
硝酸電解処理条件
濃度１０％、液温６０℃２電流密度１０Ａ／ｄｍ”。Sulfuric acid electrolytic treatment conditions: concentration 7%, liquid temperature 50°C, current density 10 A/dm2°, anode 5 seconds, cathode 5 seconds, nitric acid electrolytic treatment conditions concentration 10%, liquid temperature 60°C, current density 10 A/dm".
アノード１５秒カソード１５秒
ソルト処理および硝酸電解処理条件
ソルト処理条件
温度４３０℃１浸漬時間３０秒
硝酸電解処理条件
濃度１０％、 ｆｉ／Ｍ６０℃２電流密度１〇八／ｄｍ
”。Anode 15 seconds Cathode 15 seconds Salt treatment and nitric acid electrolysis treatment conditions Salt treatment conditions Temperature 430℃ 1 Immersion time 30 seconds Nitric acid electrolysis treatment conditions Concentration 10%, fi/M 60℃ 2 Current density 108/dm
”.
アノード５秒カソード５秒
第４表
〈発明の効果〉
本発明により熱処理ｖ４質法による高強度オーステナイ
ト系ステンレス鋼板の製造のネックとなっていた脱スケ
ールの困難さおよび表面むらの発生という問題点が解決
し、圧延調質法にくらべ多くの利点を有する熱処理調質
法を有効に活用することができるようになった。Anode: 5 seconds Cathode: 5 seconds Table 4 <Effects of the Invention> The present invention solves the problems of difficulty in descaling and occurrence of surface unevenness, which were bottlenecks in the production of high-strength austenitic stainless steel sheets using the heat treatment V4 quality method. It has now become possible to effectively utilize the heat treatment heat treatment method, which has many advantages over the rolling heat treatment method.
第１図は硝弗酸の濃度領域を示したものであり、斜線部
で示した領域Ａが本発明の範囲である。
特許出願人 川崎製鉄株式会社
第１図
ＨＦ社（％）FIG. 1 shows the concentration range of nitric-fluoric acid, and the shaded area A is the range of the present invention. Patent applicant Kawasaki Steel Corporation Figure 1 HF Company (%)
Claims (1)
度化したオーステナイト系ステンレス鋼を、硝酸電解処
理または硫酸電解処理後に、あるいはソルト処理の後の
硝酸電解処理または硫酸電解処理後に、あるいは中性塩
電解処理後に、硝弗酸に浸漬して脱スケール処理を行う
に際し、前記浸漬用硝弗酸の液組成をＨＮＯ＿３：２．
５〜５．０ｗｔ％、ＨＦ：０．６〜２．０ｗｔ％の範囲
の水溶液とすることを特徴とする高強度オーステナイト
系ステンレス鋼の酸洗方法。Austenitic stainless steel, which has been heat treated at a low temperature of 950°C or less after cold rolling to increase its strength, is processed after nitric acid electrolysis treatment or sulfuric acid electrolysis treatment, after nitric acid electrolysis treatment or sulfuric acid electrolysis treatment after salt treatment, or after nitric acid electrolysis treatment or sulfuric acid electrolysis treatment after salt treatment. After the electrolytic salt electrolysis treatment, when descaling is performed by immersion in nitric-fluoric acid, the liquid composition of the nitric-fluoric acid for dipping is HNO_3:2.
A method for pickling high-strength austenitic stainless steel, characterized by using an aqueous solution in the range of 5 to 5.0 wt% and HF: 0.6 to 2.0 wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32133687A JPH01162786A (en) | 1987-12-21 | 1987-12-21 | Method for pickling high strength austenitic stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32133687A JPH01162786A (en) | 1987-12-21 | 1987-12-21 | Method for pickling high strength austenitic stainless steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01162786A true JPH01162786A (en) | 1989-06-27 |
Family
ID=18131452
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32133687A Pending JPH01162786A (en) | 1987-12-21 | 1987-12-21 | Method for pickling high strength austenitic stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01162786A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2060641A1 (en) * | 2006-08-23 | 2009-05-20 | Nkktubes | Austenite-base stainless steel pipe, for boiler, having excellent high-temperature steam oxidation resistance |
| JP2015523469A (en) * | 2012-07-31 | 2015-08-13 | ポスコ | High speed pickling process for producing austenitic stainless cold rolled steel sheet |
| KR102255102B1 (en) * | 2019-12-05 | 2021-05-24 | 주식회사 포스코 | Manufacturing method of austenitic stainless steel with improved surface quality |
| JPWO2022049796A1 (en) * | 2020-09-01 | 2022-03-10 | ||
| JP2022041426A (en) * | 2020-09-01 | 2022-03-11 | 株式会社特殊金属エクセル | Austenitic stainless steel sheet, and method for producing the same |
-
1987
- 1987-12-21 JP JP32133687A patent/JPH01162786A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2060641A1 (en) * | 2006-08-23 | 2009-05-20 | Nkktubes | Austenite-base stainless steel pipe, for boiler, having excellent high-temperature steam oxidation resistance |
| JP5108771B2 (en) * | 2006-08-23 | 2012-12-26 | エヌケーケーシームレス鋼管株式会社 | Austenitic stainless steel pipe for boilers with excellent high-temperature steam oxidation resistance |
| EP2060641A4 (en) * | 2006-08-23 | 2013-03-20 | Nkktubes | Austenite-base stainless steel pipe, for boiler, having excellent high-temperature steam oxidation resistance |
| JP2015523469A (en) * | 2012-07-31 | 2015-08-13 | ポスコ | High speed pickling process for producing austenitic stainless cold rolled steel sheet |
| KR102255102B1 (en) * | 2019-12-05 | 2021-05-24 | 주식회사 포스코 | Manufacturing method of austenitic stainless steel with improved surface quality |
| JPWO2022049796A1 (en) * | 2020-09-01 | 2022-03-10 | ||
| WO2022049796A1 (en) * | 2020-09-01 | 2022-03-10 | 株式会社特殊金属エクセル | Austenitic stainless steel sheet and method for producing same |
| JP2022041426A (en) * | 2020-09-01 | 2022-03-11 | 株式会社特殊金属エクセル | Austenitic stainless steel sheet, and method for producing the same |
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