JPH046260A - Production of ultra-deep-drawable galvanized sheet - Google Patents
Production of ultra-deep-drawable galvanized sheetInfo
- Publication number
- JPH046260A JPH046260A JP11124990A JP11124990A JPH046260A JP H046260 A JPH046260 A JP H046260A JP 11124990 A JP11124990 A JP 11124990A JP 11124990 A JP11124990 A JP 11124990A JP H046260 A JPH046260 A JP H046260A
- Authority
- JP
- Japan
- Prior art keywords
- hot
- steel
- less
- ultra
- sheet
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 32
- 239000010959 steel Substances 0.000 claims abstract description 32
- 238000001816 cooling Methods 0.000 claims abstract description 11
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 11
- 238000005246 galvanizing Methods 0.000 claims abstract description 9
- 238000000137 annealing Methods 0.000 claims abstract description 8
- 238000010438 heat treatment Methods 0.000 claims abstract description 8
- 238000005275 alloying Methods 0.000 claims abstract description 7
- 238000005097 cold rolling Methods 0.000 claims abstract description 7
- 238000005098 hot rolling Methods 0.000 claims abstract description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 6
- 238000001953 recrystallisation Methods 0.000 claims abstract description 5
- 230000009466 transformation Effects 0.000 claims abstract description 4
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 3
- 229910001335 Galvanized steel Inorganic materials 0.000 claims description 14
- 239000008397 galvanized steel Substances 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 abstract description 4
- 238000005336 cracking Methods 0.000 abstract description 4
- 230000007547 defect Effects 0.000 description 11
- 238000007747 plating Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 9
- 238000012545 processing Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 239000010960 cold rolled steel Substances 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Landscapes
- Heat Treatment Of Sheet Steel (AREA)
- Coating With Molten Metal (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、超深絞り性溶融亜鉛めっき鋼板の製造法に
関する。この超深絞り性溶融亜鉛めっき鋼板の製造法は
、Ｔｉ、 ＮｂおよびＢを含有する冷延鋼板を素材とす
るもので、自動車用外装材あるいは自動車用内装部品等
としての使用に適する。DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to a method for producing ultra-deep drawable hot-dip galvanized steel sheets. This method of producing ultra-deep drawable hot-dip galvanized steel sheets uses cold-rolled steel sheets containing Ti, Nb, and B as raw materials, and is suitable for use as automobile exterior materials or automobile interior parts.
従来の技術
近年、自動車用外装材あるいは自動車用内装部品等とし
て、冷延鋼板を素材とする超深絞り性溶融亜鉛めっき鋼
板の需要が増加している。BACKGROUND OF THE INVENTION In recent years, there has been an increase in demand for ultra-deep drawable hot-dip galvanized steel sheets made from cold-rolled steel sheets as exterior materials for automobiles, interior parts for automobiles, and the like.
従来の超深絞り性溶融亜鉛めっき鋼板としては、Ｔｉを
含有する極低炭素鋼板が知られている。As a conventional ultra-deep drawable hot-dip galvanized steel sheet, an ultra-low carbon steel sheet containing Ti is known.
また、鋼中にＴｉを添加すると、Ｃ，ＮはＴｉｃ。Furthermore, when Ti is added to steel, C and N become TiC.
ＴｉＮとなり、固溶Ｃ１固溶Ｎの生成を制御することに
より、優れた超深絞り性が得られることも知られている
。It is also known that by controlling the formation of solid solution C1 and solid solution N, excellent ultra-deep drawability can be obtained.
しかし、Ｔｉ含有鋼は、窒化物、炭化物あるいは硫化物
の形成傾向が強く、鋼の純化作用が強いため、二次加工
割れが発生する恐れがある。However, Ti-containing steel has a strong tendency to form nitrides, carbides, or sulfides, and has a strong steel purifying effect, so there is a risk that secondary processing cracks may occur.
しかも、Ｔｉ含有量が多い鋼は、連続鋳造する際にＴｆ
−ＡＩ−Ｏｘ系の非金属介在物が生成しやすく、鋼材の
内部欠陥の発生が増加する。そして、スラブ加熱時に難
剥離性のＴｉ酸化物がスラブ表面に生成しやすく、溶融
亜鉛めっき後の合金化処理における合金層の発達に差を
生じ、めっきの表面欠陥。Moreover, steel with a high Ti content has Tf during continuous casting.
-AI-Ox-based nonmetallic inclusions are likely to be generated, increasing the occurrence of internal defects in the steel material. When the slab is heated, difficult-to-peel Ti oxides tend to form on the slab surface, causing differences in the development of the alloy layer during the alloying treatment after hot-dip galvanizing, resulting in surface defects in the plating.
どなる。bawl.
また、他に知られているＮｂ含有鋼は、熱延での高温巻
取りが必要であり、通常の巻取り温度では完全再結晶温
度が高くなり、連続焼鈍炉の可能範囲（８５０℃以下）
では、未結晶部分が残存することがある。さらに、高温
巻取りのためにスケールが厚くなり、酸洗能率が大きく
低下すると共に、コイルの長手方向での特性値に大きな
ばらつきが生じる。In addition, other known Nb-containing steels require high-temperature coiling during hot rolling, and the complete recrystallization temperature is high at normal coiling temperatures, which is within the range possible for continuous annealing furnaces (850°C or less).
In this case, uncrystallized portions may remain. Furthermore, the scale becomes thick due to high-temperature winding, which greatly reduces pickling efficiency and causes large variations in characteristic values in the longitudinal direction of the coil.
さらに、Ｔｉ Ｏ，００３〜０．２０ｗｔ％とＮｂ０．
００３〜０、０２５ｗｔ％を含有する極低炭素鋼板が知
られている（特開昭５９−７４２３１号公報）。この鋼
板は、内部欠陥がなく、めっき表面性状が良好であるが
、機械試験の測定値にバラツキが見られる。Furthermore, TiO,003~0.20wt% and Nb0.
An ultra-low carbon steel sheet containing 0.003 to 0.025 wt% is known (Japanese Unexamined Patent Publication No. 74231/1983). This steel plate has no internal defects and has good plating surface quality, but there are variations in the measured values of mechanical tests.
発明が解決しようとする課題
前記溶融亜鉛めっき鋼板は、自動車用外装材として適用
するには、前記したとおり介在物による内部欠陥や、め
っき層の発達差による表面欠陥が大きな問題となる。Problems to be Solved by the Invention When the hot-dip galvanized steel sheet is applied as an exterior material for automobiles, as described above, internal defects due to inclusions and surface defects due to differences in the development of the plating layer pose major problems.
また、前記溶融亜鉛めっき鋼板は、超深絞りの自動車用
内装部品として使用すると、寒冷地において何らかの衝
撃によって二次加工脆性破壊が生じ、致命的欠陥となる
問題が発生している。Further, when the hot-dip galvanized steel sheet is used as an ultra-deep drawn automobile interior part, secondary processing brittle fracture occurs due to some kind of impact in cold regions, resulting in a fatal defect.
この発明は、上記問題点を排除し、表面性状に優れ、か
つ低温における耐二次加工割れにも優れた超深絞り性溶
融亜鉛めっき鋼板の製造法を提供することを目的とする
ものである。The purpose of the present invention is to eliminate the above-mentioned problems and provide a method for manufacturing an ultra-deep drawable hot-dip galvanized steel sheet that has excellent surface properties and excellent resistance to secondary work cracking at low temperatures. .
課題を解決するための手段
良好な機械試験値を得るには、Ｔｉ添加が有効であるが
、鋼中のＴｉ含有量を低減し、Ｎｂ含有量を増加するこ
とにより機械試験値は低下する。しかしめっき表面性状
および鋼板の内部性状は、Ｔｉ含有量を低減し、Ｎｂ含
有量を増加することにより良好となる。Means for Solving the Problems Addition of Ti is effective in obtaining good mechanical test values; however, by reducing the Ti content and increasing the Nb content in steel, the mechanical test values decrease. However, the plating surface properties and the internal properties of the steel sheet become better by reducing the Ti content and increasing the Nb content.
そこで、機械試験値が良好で、めっき表面性状および鋼
板の内部性状の優れた溶融亜鉛めっき鋼板を製造するに
は、Ｔｉ、 Ｎｂの複合含有量の最適範囲が存在するこ
とが判明した。Therefore, it has been found that there is an optimal range for the combined content of Ti and Nb in order to produce hot-dip galvanized steel sheets with good mechanical test values and excellent coating surface properties and internal steel sheet properties.
また、鋼中にＢを所定量添加すると、深絞り成形後の衝
撃力による二次加工割れに対して、脆性破壊発生温度の
低下をもたらすことが判明した。It has also been found that adding a predetermined amount of B to steel lowers the temperature at which brittle fracture occurs with respect to secondary processing cracking due to impact force after deep drawing.
すなわちこの発明は、重量比で、
Ｃ：０．００５％以下、 Ｓｉ ： ０．１０％以下
、Ｍｎ ： １．５０％以下、 Ｐ：０．１０％以
下、Ｓ ： ０．０１０％以下、
ｓｏｌ Ａｌ ： ０．０１〜０．１０％、Ｎ：０．０
０５％以下、
およびＴｉとＮｂを下記式を満足して複合金有し、４８
／１４Ｎ （Ｚ） ＋ ４８／３２Ｓ（Ｘ） ＋ ４８
／１２ （Ｃ（ｚ） −０，００１％｝≦Ｔｉ≦０．０
３５％
２Ｃ（Ｚ）≦Ｎｂ≦０．０１５％
かつ、Ｂ ： ０．０００５〜０．０１５％を含有し、
残部がＦｅと不可避的不純物よりなる鋼を、通常の熱間
圧延を施し、脱スケール処理し、さらに冷間圧延して所
定板厚の薄板に仕上げたのち、７３０℃〜Ａｊ変態点の
温度に加熱し冷却途中の７３０〜５００℃の温度範囲を
、冷却速度１．５〜ｂ結晶焼鈍し、引続き溶融亜鉛めっ
きしたのち加熱して合金化処理を施すのである。That is, this invention provides the following in terms of weight ratio: C: 0.005% or less, Si: 0.10% or less, Mn: 1.50% or less, P: 0.10% or less, S: 0.010% or less, sol Al: 0.01-0.10%, N: 0.0
05% or less, and has a composite metal containing Ti and Nb satisfying the following formula, 48
/14N (Z) + 48/32S(X) + 48
/12 (C(z) -0,001%}≦Ti≦0.0
35% 2C(Z)≦Nb≦0.015% and contains B: 0.0005 to 0.015%,
The steel, the balance of which is Fe and unavoidable impurities, is subjected to normal hot rolling, descaling treatment, and cold rolling to finish it into a thin plate of a predetermined thickness, and then heated to a temperature of 730°C to the Aj transformation point. During heating and cooling, crystal annealing is carried out in the temperature range of 730 to 500° C. at a cooling rate of 1.5 to b, followed by hot-dip galvanizing, followed by heating and alloying treatment.
作 用
上記のとおりこの発明は、Ｔｉ、 ＮｂおよびＢの含有
量を限定して複合金有せしめた鋼材を、熱間圧延、冷間
圧延して鋼板に仕上げ、その冷延鋼板に再結晶焼鈍を施
したのち、溶融亜鉛めっきして合金化処理することによ
って、表面欠陥がなく、かつ鋼板内部に非金属介在物に
よる欠陥を有しない優れた溶融亜鉛めっき鋼板が得られ
る。Function As described above, the present invention involves hot-rolling and cold-rolling a steel material with a composite metal by limiting the content of Ti, Nb, and B into a steel plate, and then recrystallizing and annealing the cold-rolled steel plate. After that, by hot-dip galvanizing and alloying, an excellent hot-dip galvanized steel sheet with no surface defects and no defects due to non-metallic inclusions inside the steel sheet can be obtained.
この発明による溶融亜鉛めっき鋼板は、優れためっき表
面性状を有し、かつ内部欠陥を有していない。これはＴ
ｉとＮｂを特定した含有量で複合金有せしめたからであ
る。The hot-dip galvanized steel sheet according to the present invention has excellent plating surface properties and has no internal defects. This is T
This is because the composite gold was made with a specified content of i and Nb.
鋼中にＴ１、Ｎｂを添加すると、鋼中のＣ，ＮはＴｉＮ
、 ＴｊＣ，ＮｂＣとして析出固定され、良好な鋼材が
得られる。When T1 and Nb are added to steel, C and N in the steel become TiN.
, TjC, and NbC are precipitated and fixed, resulting in a good steel material.
また、鋼中にＢを所定量含有せしめることによって、絞
り成形後の衝撃力による二次加工割れに対して脆性破壊
発生温度を低下せしめることができる。Furthermore, by containing a predetermined amount of B in the steel, the temperature at which brittle fracture occurs can be lowered with respect to secondary processing cracks caused by impact force after drawing.
つぎにこの発明において鋼組成ならびに製造工程を限定
した理由を詳述する。なお、以降の％はすべで重量％を
示す。Next, the reason for limiting the steel composition and manufacturing process in this invention will be explained in detail. Note that all percentages hereinafter indicate weight percentages.
この発明におけるＴｉ、 Ｎｂの複合含有量は、前記知
見に基づいて決定した。すなわち、Ｔｉ含有量は、機械
試験値の安定化対策より固溶Ｃ≦１０ｐｐｍの条件から
下限値が規定され、
４８／１４ Ｎ （Ｚ）＋４８／３２ Ｓ （ｚ）＋４
８／１２（％）−ｏ、 ｏｏｉｏχ）
となる。また、上限値は、めっき表面性状、鋼板の内部
性状から ０．０３５％となる。The combined content of Ti and Nb in this invention was determined based on the above findings. In other words, the lower limit of the Ti content is specified based on the condition of solid solute C≦10 ppm in order to stabilize mechanical test values, and is 48/14 N (Z) + 48/32 S (z) + 4
8/12(%)-o, ooioχ). Furthermore, the upper limit is 0.035% based on the plating surface properties and the internal properties of the steel sheet.
Ｎｂ含有量は、複合析出物を形成させるため２Ｃ（％）
以上が必要であり、機械試験値の安定からは０．０１５
％以下とする。The Nb content is 2C (%) to form composite precipitates.
The above is necessary, and from the stability of the mechanical test value, 0.015
% or less.
次に、鋼板の他の成分元素の含有量を限定した理由を説
明する。Next, the reason for limiting the content of other component elements of the steel sheet will be explained.
Ｂ含有量は、深絞り成形後の衝撃力による二次加工割れ
に対して脆性破壊発生温度の低下をもたらす。その効果
はＢ含有量０．０００５％以上で発生するが０．００１
５％を超えて含有すると、伸び及びｒ値の低下が顕著と
なり深絞り用材料としては不適切のため、上限を０．０
０１５％と限定した。The B content lowers the temperature at which brittle fracture occurs with respect to secondary processing cracking due to impact force after deep drawing. The effect occurs when the B content is 0.0005% or more, but 0.001
If the content exceeds 5%, the elongation and r value will drop significantly, making it unsuitable as a material for deep drawing, so the upper limit should be set at 0.0.
It was limited to 0.015%.
Ｃ含有量は、多くなればＣを固定するのに必要なＴｉ、
Ｎｂの添加量が増加し、製造コストが高くなると共に
、ＴｉＣ，ＮｂＣの析出により超深絞り性に悪影響を及
ぼす。このため０．００５％以下とした。The higher the C content, the more Ti is needed to fix C.
As the amount of Nb added increases, manufacturing costs increase, and precipitation of TiC and NbC adversely affects ultra-deep drawability. For this reason, the content was set at 0.005% or less.
Ｓｉは、亜鉛めっき層の安定した密着性を得るため０．
１０％以下とする。Si is 0.0% to obtain stable adhesion of the galvanized layer.
10% or less.
Ｍｎは、鋼に強度を与えるのに必要な元素であるが、プ
レス成形性を考慮して１．５０％以下とする。Mn is an element necessary to give strength to steel, but it is set to 1.50% or less in consideration of press formability.
Ｐは、最も強化能の大きな元素で強度を増大するには有
効であるが、０．１０％を超えて多く含有すると粒界偏
析を起こし二次加工割れの原因となるから、０．１０％
以下とする。P is an element with the highest strengthening ability and is effective in increasing strength, but if it is contained in a large amount exceeding 0.10%, it causes grain boundary segregation and causes secondary processing cracks, so 0.10%
The following shall apply.
Ｓは、Ｔ１との親和力が強く、あまり多すぎるとＴｉＳ
となり、Ｃ，Ｎを固定する有効Ｔｉ量が減少するため０
．０１０％以下におさえる必要がある。S has a strong affinity with T1, and too much S causes TiS.
0 because the effective amount of Ti that fixes C and N decreases.
．． It is necessary to keep it below 0.010%.
ＡＩは、Ｎｂ、 Ｔｉ添加前の溶鋼脱酸剤として加える
がＴｉ、 Ｎｂの歩留を良くするためには０．０１％以
上の添加が必要である。また、あまり加えすぎるとコス
トが増大するため、その上限値を０．１％とした。AI is added as a deoxidizing agent for molten steel before adding Nb and Ti, but in order to improve the yield of Ti and Nb, it is necessary to add 0.01% or more. Furthermore, since adding too much increases the cost, the upper limit was set at 0.1%.
Ｎは、良好な加工性を得るには少ないことが望ましいが
、鋼中に存在するＮの大部分はＴｉによりＴｉＮとして
固定される。しかし、Ｎ量が多いとＴｉ量も多くを必要
どするため０．００５％以下とした。Although a small amount of N is desirable in order to obtain good workability, most of the N present in steel is fixed as TiN by Ti. However, if the amount of N is large, the amount of Ti also needs to be large, so it is set to 0.005% or less.
冷間圧延後の再結晶焼鈍は、再結晶に必要な７３０℃〜
Ａ３変態点の温度範囲に加熱する。なお、焼鈍温度から
５００℃までの冷却速度は、表面濃化を起させ十分な密
着性のあるめっき層を形成するには１．５℃／秒以上が
必要であるが、１５０℃／秒を超えて速くすると板形状
が不安定となるため好ましくない。また、冷却の所要時
間は十分な表面濃化を起させるためには５０秒以上が必
要であるが、１５０秒を超えても表面濃化の効果は変ら
ず、作業能率が低下するので、５０〜１５０秒とした。Recrystallization annealing after cold rolling is performed at a temperature of 730°C or higher, which is necessary for recrystallization.
Heat to a temperature range of A3 transformation point. Note that the cooling rate from the annealing temperature to 500°C needs to be 1.5°C/second or more to cause surface concentration and form a plating layer with sufficient adhesion, but 150°C/second is required. If the speed is exceeded, the plate shape becomes unstable, which is not preferable. In addition, the time required for cooling is 50 seconds or more in order to cause sufficient surface concentration, but even if it exceeds 150 seconds, the effect of surface concentration will not change and the work efficiency will decrease. ~150 seconds.
実施例 この発明の実施例について説明する。Example Examples of this invention will be described.
第１表に示す組成のこの発明の実施による鋼および比較
のための鋼を転炉にて溶製し、真空脱ガス処理したのち
連続鋳造してスラブとした。Steel according to the present invention and steel for comparison having the compositions shown in Table 1 were melted in a converter, subjected to vacuum degassing treatment, and then continuously cast into slabs.
これらの各種のスラブに通常の熱間圧延と冷間圧延を施
して板厚０．８ｍｍの冷延鋼板を得た。そして、溶融亜
鉛めっきラインにおいて７８０℃に加熱して３０秒保持
して焼鈍した。冷却時の７３０℃から５００℃までの所
要時間は５５秒で、平均冷却速度は４．２℃／ｓｅｃで
あった。溶融亜鉛めっき槽を通して両面に４５ ｇ ／
ｍ”の亜鉛めっきを施し、さらに６００℃に加熱して合
金化処理を行ったのち、スキンパス伸び率を ０．８％
かけて仕上げた。These various slabs were subjected to conventional hot rolling and cold rolling to obtain cold rolled steel plates having a thickness of 0.8 mm. Then, it was annealed by heating it to 780° C. and holding it for 30 seconds in a hot-dip galvanizing line. The time required for cooling from 730°C to 500°C was 55 seconds, and the average cooling rate was 4.2°C/sec. 45 g/dip on both sides through hot dip galvanizing bath
After applying zinc plating and further heating to 600℃ to perform alloying treatment, the skin pass elongation rate was reduced to 0.8%.
I finished it.
そして、各種の溶融亜鉛めっき鋼板から試料を採取して
機械的性質の試験を行った。なお、引張り試験片はＪＩ
Ｓ ５号で引張方向は圧延方向とした。Then, samples were taken from various hot-dip galvanized steel sheets and tested for mechanical properties. In addition, the tensile test piece is JI
In No. S5, the tensile direction was the rolling direction.
また、耐二次加工脆性の調査は、コニカルカップ試験機
により絞り比２．４まで加工後、落電エネルギー５０ｋ
ｇｍ （５０ｋｇＸ １ｍ）の落電試験を行ない、その
破面観察により脆性割れ長さ率が５０％となる脆性遷移
温度を測定した。In addition, the investigation of secondary processing brittleness was carried out using a conical cup testing machine with an electric shock energy of 50 k after processing to a drawing ratio of 2.4.
gm (50 kg x 1 m) was conducted, and the brittle transition temperature at which the brittle crack length ratio was 50% was measured by observing the fracture surface.
さらに、内部品質は、超音波探傷法により評価し、めっ
き表面性状は目視による表面傷の発生の程度により評価
した。その結果を第２表に示す。Furthermore, the internal quality was evaluated by ultrasonic flaw detection, and the plating surface quality was evaluated by the degree of surface flaws visually observed. The results are shown in Table 2.
第２表に示すとおり、この発明の実施によるＮｏ、 １
０〜１５の溶融亜鉛めっき鋼板は、比較例のＮｏ、 １
〜９の鋼板に比較し、いずれも伸び、ｒ値をはじめとし
て各機械試験値が高く、さらに絞り成形後の落電試験に
おける脆性遷移温度も低い。As shown in Table 2, No. 1 according to the implementation of this invention
Hot-dip galvanized steel sheets numbered 0 to 15 are Comparative Example No. 1
Compared to the steel plates No. 9 to 9, each mechanical test value including elongation and r value is higher, and the brittle transition temperature in the electric drop test after drawing is also lower.
また、めっき表面性状が良好で内部欠陥がなく、全体的
に品質が優れていることがわかる。It can also be seen that the plating surface properties are good, there are no internal defects, and the quality is excellent overall.
以下余白
発明の効果
この発明によれば、内部欠陥がなく機械的性質および耐
二次加工脆性に優れ、しかも、めっき表面性状の良好な
溶融亜鉛めっき鋼板を、溶融亜鉛めっきライン上で効率
よく製造することができる。Effects of the Invention According to the invention, hot-dip galvanized steel sheets that are free from internal defects, have excellent mechanical properties and resistance to secondary work brittleness, and have good coating surface properties can be efficiently manufactured on a hot-dip galvanizing line. can do.
Claims (1)
１．５０％以下、Ｐ：０．１０％以下、Ｓ：０．０１０
％以下、 ｓｏｌ．Ａｌ：０．０１〜０．１０％、 Ｎ：０．００５％以下、 およびＴｉとＮｂを下記式を満足して複合含有し、４８
／１４Ｎ（％）＋４８／３２Ｓ（％）＋４８／１２｛Ｃ
（％）−０．００１％｝≦Ｔｉ≦０．０３５％ ２Ｃ（％）≦Ｎｂ≦０．０１５％ かつ、Ｂ：０．０００５〜０．０１５％ を含有し、残部がＦｅと不可避的不純物よりなる鋼を、
通常の熱間圧延を施し、脱スケール処理し、さらに冷間
圧延して所定板厚の薄板に仕上げたのち、７３０℃〜Ａ
＿３変態点の温度に加熱し冷却途中の７３０〜５００℃
の温度範囲を、冷却速度１．５〜１５０℃／秒で、かつ
所要時間５０〜１５０秒で冷却して再結晶焼鈍し、引続
き溶融亜鉛めっきしたのち、加熱して合金化処理を施す
ことを特徴とする超深絞り性溶融亜鉛めっき鋼板の製造
法。[Claims] 1. In weight ratio: C: 0.005% or less, Si: 0.10% or less, Mn:
1.50% or less, P: 0.10% or less, S: 0.010
% or less, sol. Al: 0.01 to 0.10%, N: 0.005% or less, and complex containing Ti and Nb satisfying the following formula, 48
/14N(%)+48/32S(%)+48/12{C
(%) -0.001%}≦Ti≦0.035% 2C (%)≦Nb≦0.015% and B: 0.0005 to 0.015%, the balance being Fe and unavoidable impurities. More steel,
After applying normal hot rolling, descaling treatment, and further cold rolling to finish a thin plate with a specified thickness, 730℃~A
_3 730-500℃ during cooling after heating to transformation point temperature
Recrystallization annealing is carried out by cooling within a temperature range of 1.5 to 150°C/sec for a required time of 50 to 150 seconds, followed by hot-dip galvanizing, followed by heating and alloying treatment. A manufacturing method for ultra-deep drawable hot-dip galvanized steel sheets.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11124990A JPH046260A (en) | 1990-04-25 | 1990-04-25 | Production of ultra-deep-drawable galvanized sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11124990A JPH046260A (en) | 1990-04-25 | 1990-04-25 | Production of ultra-deep-drawable galvanized sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH046260A true JPH046260A (en) | 1992-01-10 |
Family
ID=14556385
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11124990A Pending JPH046260A (en) | 1990-04-25 | 1990-04-25 | Production of ultra-deep-drawable galvanized sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH046260A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0613961A1 (en) * | 1993-03-04 | 1994-09-07 | Kawasaki Steel Corporation | Alloyed hot dip galvanized steel sheet |
| CN102660710A (en) * | 2012-05-09 | 2012-09-12 | 河北钢铁股份有限公司邯郸分公司 | Nb/Ti composite extra-deep drawing galvanized sheet and production method thereof |
-
1990
- 1990-04-25 JP JP11124990A patent/JPH046260A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0613961A1 (en) * | 1993-03-04 | 1994-09-07 | Kawasaki Steel Corporation | Alloyed hot dip galvanized steel sheet |
| CN102660710A (en) * | 2012-05-09 | 2012-09-12 | 河北钢铁股份有限公司邯郸分公司 | Nb/Ti composite extra-deep drawing galvanized sheet and production method thereof |
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