KR20110046689A - High strength steel sheet with excellent resistivity ratio and manufacturing method - Google Patents

Abstract

The present invention relates to a high strength steel sheet and a method of manufacturing the same having excellent resistance ratio ratio characteristics. In the present invention, C: 0.04 to 0.08 wt%, Si: more than 0 wt% or less, Mn: 1.8 to 2.0 wt%, Al: 0.1 to 0.2 wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% % Or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: more than 0 and 0.006 wt% or less, Cr: 0.1 to 0.2 wt%, V: 0.01 to 0.05 wt%, B: 0.0005 to 0.0015 At least one selected from wt%, the balance is composed of Fe and other unavoidable impurities, the microstructure consists of two phases, including ferrite and martensite.

The present invention uses a complex phase (CP) steel, but secures martensite fraction 10 ~ 15vol% and controls the precipitation of BN, AlN, etc. by the addition of Ti, excellent elongation with high strength and resistance to complex ratio There is an advantage that can produce an excellent high strength steel sheet.

High strength steel sheet, resistive ratio

Description

High-strength steel sheet with excellent resistivity ratio and its manufacturing method {Steel sheet having excellent low yield ratio property, and method for producing the same}

The present invention relates to a steel sheet and a method for manufacturing the same, and more particularly, to a high strength steel sheet and a method for manufacturing the same, which is excellent in press formability and excellent in resistivity ratio property having a tensile strength of 590 MPa or more.

Since most automotive parts are molded by press processing, excellent press formability is required. In particular, as the design of automobiles is complicated and the needs of consumers are diversified, demand for steel with high strength and excellent plating and workability is required. .

For example, steel sheets mainly used for exterior materials of automobiles and the like are used IF (Interstitial) steel of 340 MPa or less.

IF (Interstitial) steel removes carbon and solid solution of nitrogen to secure aging resistance, and Mn, Si, and P are added to prevent aging after securing aging resistance.

Such IF steel has the advantage of excellent formability and surface properties.

However, IF steel has a small amount of solid carbon, so that the dent resistance is low, and a thickness of 0.65 mm or more is required to secure shell strength.

To compensate for this, BH (Bake Hardening) steel may be used, but in this case, it is difficult to secure aging and narrow management of C and N components.

Therefore, an object of the present invention is to solve the problems described above, it is easy to ensure the aging resistance, does not require the narrow management of the C, N components, excellent press workability and excellent resistance to composite properties and its production To provide a way.

According to a feature of the present invention for achieving the above object, the present invention is C: 0.04 ~ 0.08wt%, Si: more than 0 wt% or less, Mn: 1.8 ~ 2.0wt%, Al: 0.1 ~ 0.2wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: more than 0 and 0.006 wt% or less, Cr: 0.1 to 0.2 wt% , V: 0.01 ~ 0.05wt%, B: 0.0005 ~ 0.0015wt% It contains at least one selected from the rest, the balance is composed of Fe and other unavoidable impurities, the microstructure consists of two phases including ferrite and martensite.

The microstructure has a volume fraction of 85 to 90 vol% of ferrite and 10 to 15 vol% of martensite.

The martensite is spherical and finely dispersed in grain boundaries.

C: 0.04 to 0.08 wt%, Si: more than 0 wt% or less, Mn: 1.8 to 2.0 wt%, Al: 0.1 to 0.2 wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: over 0, 0.006 wt% or less, Cr: 0.1 to 0.2 wt%, V: 0.01 to 0.05 wt%, B: 0.0005 to 0.0015 wt% Reheat the slab containing one or more selected ones and the balance with Fe and other unavoidable impurities to 1150 ~ 1250 ℃, then finish hot rolling at Ar3 ~ Ar3 + 70 ℃ and wound at 550 ~ 650 ℃ Manufacturing a steel sheet; Pickling and hot rolling the hot rolled steel sheet to produce a cold rolled steel sheet; And annealing heat treatment of the cold rolled steel sheet to maintain 10 to 15 vol% of austenite and hot dip galvanizing.

The annealing heat treatment is cooled to a temperature range of 400 ~ 500 ℃ at a cooling rate of 5 ~ 30 ℃ / sec after the heat treatment in the temperature range of Ar1 ~ Ar3.

The temperature range of Ar1 to Ar3 is 760 to 840 ° C.

The present invention controls the precipitation of BN, AlN, etc. by controlling the addition of Si content and the hardenable element and Ti, and composed of a two-phase structure including ferrite and martensite, but retained 10 ~ 15wt% of austenite during annealing heat treatment. A high strength steel sheet having a tensile strength of 590 MPa or more, an elongation of 28% or more, and a yield ratio of less than 60% is produced.

Therefore, it is easy to process the shape of the part, it is possible to reduce the thickness of the steel sheet due to the increase in strength to reduce the total weight of the vehicle can contribute to the improvement of fuel efficiency.

In addition, since complex phase (CP) steel is used to secure high strength, the shape freezing property is also excellent because it has resistance ratio ratio characteristics without requiring narrow management of C and N components.

Hereinafter, a preferred embodiment of a high strength steel sheet and a method of manufacturing the same having excellent resistance ratio ratio according to the present invention will be described in detail.

In the present invention, C: 0.04 to 0.08 wt%, Si: more than 0 wt% or less, Mn: 1.8 to 2.0 wt%, Al: 0.1 to 0.2 wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% % Or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: more than 0 and 0.006 wt% or less, Cr: 0.1 to 0.2 wt%, V: 0.01 to 0.05 wt%, B: 0.0005 to 0.0015 It comprises at least one selected from wt% and the balance is composed of Fe and other unavoidable impurities.

In the manufacturing method, the slab having the above-described alloy composition is reheated to 1150 to 1250 ° C., followed by finishing hot rolling at Ar 3 to Ar 3 + 70 ° C., and then wound in the form of a steel coil at 550 to 650 ° C. to produce a hot rolled steel sheet.

This hot rolled steel sheet is pickled and cold rolled at a reduction ratio of 50 to 70%. After the cold-rolled steel sheet annealing in Ar1 ~ Ar3, and then cooled to 400 ~ 500 ℃ at a cooling rate of 5 ~ 30 ℃ / sec. After cooling to 400 ~ 500 ℃, hot dip galvanized and alloy heat treatment.

Microstructure consists of two phases, ferrite and martensite.

The percentage of ferrite tissue is 85-90 vol%, and the percentage of martensite tissue is 10-15 vol%.

The structure is determined by the alloying component and the cooling pattern. If the martensite phase ratio is less than 10 vol%, it is difficult to secure the target strength, and if it exceeds 15 vol%, it is difficult to secure the elongation.

Martensite is spherical and finely dispersed in grain boundaries. This martensite structure is effective in lowering brittleness and increasing elongation and its shape is shown in FIG. 1. The grain size of such martensite is about 5-10 탆.

Tensile strength is above 590MPa and elongation is above 32%. Yield ratio is less than 60%.

To this end, the alloy composition facilitates the formation of martensite by selectively adding Cr, V, and B in addition to Mo as the hardenable element.

In addition, the content of Si is limited to 0.1wt% or less to secure the plating properties, and the problem of the decrease in hardness and carbon concentration in austenite, which may be caused by the Si content limitation, is compensated by the addition of Al, Cr, and P. .

In addition, S is limited to 0.003 wt% or less to maintain the Mn effect. This prevents material degradation after heat treatment by MnS inclusion formation.

In addition, as shown in Figure 1, by adding Ti to form TiN, TiS in the high temperature zone to maximize the effect of solid solution B, Mn, Al to promote martensite formation. Such Ti suppresses the formation of BN and also prevents a decrease in elongation due to grain refinement.

Hereinafter, the reason for limitation of the function and content of the alloying elements of the present invention will be described.

C: 0.04-0.08 wt%

C is added to ensure the strength of the material. In the case of the present invention, the low carbon range [C: 0.04 to 0.08 wt%] is set to secure an amount of solid solution carbon so as to easily ensure aging resistance. In this case, there is an advantage that does not need to narrowly manage the C, N content.

When C is less than 0.04 wt%, austenite is transformed into ferrite, making it difficult to secure the martensite fraction and decreasing the strength. On the contrary, when it exceeds 0.08 wt%, weldability will fall and ductility and stretch-flange property will fall with the strength increase.

Therefore, the content of C is set to 0.04 to 0.08 wt%.

Si: more than 0 and less than 0.1wt%

Si is a solid solution strengthening element, which promotes the cleansing of the steel and the carbon concentration in the austenite to facilitate the formation of ferrite. In addition, in the steel to which the appropriate Mn is added, the fluidity of the molten metal during welding is improved to minimize the inclusion of inclusions in the weld. In addition, it improves the strength without inhibiting the balance of yield ratio and elongation, and slows the diffusion rate of carbon in the ferrite, thereby inhibiting carbide growth to stabilize the ferrite, thereby improving the elongation.

When Si exceeds 0.1wt%, Mn ₂ SiO ₄ phase is formed on the surface of the material, thereby decreasing plating wettability and deteriorating appearance surface quality.

Therefore, the content of Si is set to 0 seconds and 0.1 wt% or less.

Mn: 1.8 ~ 2.0wt%

Mn is a solid solution strengthening element, stabilizes austenite, lowers the two-phase annealing temperature, and makes martensite easily formed even at a low critical cooling rate.

When a small amount of Mn is added, austenite is transformed into bainite and pearlite during the annealing heat treatment section, thereby causing a decrease in strength. Therefore, an addition of 1.8 wt% or more is required. However, if the content exceeds 2.0wt%, the manganese band is developed at the center of the thickness of the material, thereby decreasing the bending workability.

Therefore, the content of Mn is set to 1.8 ~ 2.0wt%.

Al: 0.1-0.2wt%

Al is an element mainly used as a deoxidizer. Al stabilizes austenite by stabilizing ferrite grains to improve elongation and austenite carbon enrichment. Al also acts as a layer between the Fe and Zn plating layers to improve plating properties. In addition, Al suppresses the formation of manganese bands in the hot rolled coil, thereby preventing the elongation from decreasing.

If Al is less than 0.1 wt%, the above-described effects cannot be expected. If it exceeds 0.2 wt%, Al deteriorates the playability and forms AlN in the slab, causing hot rolled cracks.

Therefore, the content of Al is set to 0.1 ~ 0.2wt%.

P: 0.015 ~ 0.020wt%

P is an element which raises the strength of the steel sheet by solid solution strengthening. In addition, P is an effective element for inhibiting carbide formation and plays a role in preventing elongation due to carbide formation in the overaging zone.

In addition, P is effective to secure the martensite fraction by improving the Mn equivalent.

If P is less than 0.015 wt%, the above-described effects cannot be obtained. On the contrary, if P is more than 0.020 wt%, a steatite structure of Fe ₃ P is formed, which causes hot brittleness. The steatite structure is an austenite structure containing Fe ₃ P.

Therefore, the content of P is set to 0.015 ~ 0.020wt%.

S: greater than 0 and less than 0.003wt%

S inhibits toughness and weldability and increases MnS non-metallic inclusions, reducing the Mn effect in DP steel. In addition, excessive addition increases coarse inclusions and degrades fatigue characteristics.

Therefore, the content of S is limited to more than 0 and 0.003wt% or less.

Mo: 0.10 ~ 0.20wt%

Mo is a hardenable element to secure the martensite fraction to improve the strength. Mo must be added more than 0.10wt% to compensate for the hardenability due to Mn management.

However, exceeding 0.20wt% causes an increase in yield ratio due to grain refinement.

Therefore, the content of Mn is managed to 0.10 ~ 0.20wt% or less.

Ti: 0.01 ~ 0.02wt%

Ti is a strong carbonitride forming element. Ti combines with N in steel at a ratio of 3.4: 1 to reduce solid solution N. Reduction of solid solution N prevents the formation of BN and AlN, thereby preventing the yield ratio from being increased by grain refinement.

The amount of Ti is determined by the amount of solid solution N. However, in the case of excessive addition, Ti is combined with C in steel to improve the yield ratio.

If Ti is less than 0.01wt%, the above-described effects cannot be obtained, and if it exceeds 0.02wt%, the yield ratio is increased, so the content is set to 0.01 to 0.02wt%.

N: more than 0 and less than 0.006wt%

N refines the grains by the formation of AlN, but supersaturates during cooling in the alloying process of the zinc plated layer during hot dip galvanizing to lower uniform elongation.

Therefore, the content of N is limited to more than 0 and 0.006wt% or less.

[Optional Additives]

Cr: 0.1-0.2wt%

Cr is a hardenable element to secure the martensite fraction, thereby effectively improving the strength. In addition, Cr stabilizes ferrite grains to improve elongation and austenite carbon enrichment to stabilize austenite.

Cr cannot achieve the above-mentioned effect at less than 0.1 wt%, and if it exceeds 0.2 wt%, the plating property is inhibited.

Therefore, the content of Cr is set to 0.1 ~ 0.2wt%.

V: 0.01 ~ 0.05wt%

V is a strong hardenable element such as B and Mo and is an effective element for forming martensite. In addition, V is combined with carbon in the ferrite to form carbide in the mouth to improve the strength and to lower the solid solution C serves to reduce the yield ratio.

When V is less than 0.01wt%, the above-mentioned effect cannot be obtained, and when it exceeds 0.05wt%, yield strength is increased.

Therefore, the content of V is set to 0.01 to 0.05 wt%.

B: 0.0005 ~ 0.0015wt%

B is a strong hardenable element and shows a strong effect even in a small amount.

B must be added at least 0.0005wt% to have an effective property for martensite formation. On the other hand, if it exceeds 0.0015wt%, it segregates at the surface grain boundary and acts as an element that inhibits the plating property.

Therefore, the content of B is set to 0.0005 ~ 0.0015wt%.

The present invention contains the components of the steel sheet, the rest are substantially iron (Fe) and unavoidable elements, the fine content of inevitable impurities of less than 0.01w% as an element contained according to the situation of raw materials, materials, manufacturing facilities, etc. Is allowed.

The slabs having the composition as described above are obtained through a continuous casting process after obtaining molten steel through a steelmaking process, where the steel slab is manufactured in the form of a steel sheet through hot rolling, cold rolling to heat the slab to a desired thickness. Subsequently, annealing heat treatment is performed for the resistive ratio property and hot dip galvanizing is performed on the surface of the steel sheet.

 Each process is as follows.

[Heating process]

The slab having the composition described above is reheated at 1150 to 1250 ° C. to re-use segregated components during casting.

If the reheating temperature is lower than 1150 ° C, segregated components are not reusable, and if the reheating temperature is higher than 1250 ° C, austenite grains are coarsened, thereby making it difficult to secure strength.

In this case, the reheating time is preferably 1 to 3 hours, and if it is maintained longer, economic loss may occur, and if it is too short, the segregated components during casting may not be re-used.

[Hot Rolling Process]

The reheated slab is hot rolled at austenitic single-phase Ar3 ~ Ar3 + 70 ℃. After finishing hot rolling, it is wound at 550 ~ 650 ℃ to prevent surface concentration of Mn and Si and coarsening of carbide.

When finishing rolling below the Ar3 temperature, excessive dislocations may be introduced into the ferrite and grow during cooling or winding to form coarse grains on the surface. On the other hand, when finish rolling at a temperature exceeding Ar3 + 70 ℃ ferrite grain size is increased there is a fear that the strength is reduced. The temperature range of Ar3 ~ Ar3 + 70 ℃ is 880 ~ 950 ℃.

If the coiling temperature is lower than 550 ℃, bainite or martensite is formed instead of ferrite, and if higher than 650 ℃, surface concentration of Mn, Si and coarsening of carbide may occur.

After hot rolling, cool to normal winding speed until the coiling temperature.

Pickling process

Hot rolled steel sheet is pickled to remove surface scale and oil is applied to prevent oxidation.

[Cold rolling process]

The pickled hot rolled steel sheet (PO steel sheet) is cold rolled at a rolling reduction of 50 to 70%.

The cold rolling process is a step of cold rolling to obtain the final desired thickness of the steel sheet and to obtain the desired material.

[Annealing process]

The martensite fraction is controlled in the annealing process.

To this end, after performing a heat treatment in the temperature range of Ar1 ~ Ar3, the austenite ferrite ideal zone section, and cooled to 400 ~ 500 ℃ (over-age band) at a cooling rate of 5 ~ 30 ℃ / sec.

At this time, if the cooling rate is too slow, austenite is transformed into ferrite ferrite (cementite), bainite in the cooling process, and when the cooling rate is too fast, a problem of material unevenness occurs.

Ar1 ~ Ar3 region is determined according to the alloy composition in the case of the present invention is 760 ~ 840 ℃ temperature range.

Part of the ferrite transforms to austenite during annealing heat treatment, and the austenite remains to transform into martensite upon cooling after alloying heat treatment.

At this time, by controlling the cooling conditions to suppress the transformation of austenite into ferrite, pearlite and bainite to ensure an appropriate martensite fraction.

If the cooling rate is less than 5 ° C./sec, the carbon solubility in austenite is lowered in the overageing zone, thereby increasing the residual austenite volume fraction. This results in an excessive martensite fraction, which increases yield strength and decreases elongation.

On the other hand, if the cooling rate exceeds 30 ℃ / sec austenite is transformed into ferrite, pearlite (cementite), bainite during the cooling process to reduce the residual austenite volume fraction in the overaging zone. Therefore, it is difficult to secure martensite fraction.

At this time, if the cooling end temperature (over-aging band temperature) is less than 400 ℃ difficult to secure the appropriate austenite fraction is difficult to secure the strength, if it exceeds 500 ℃ it is difficult to expect the effect of improving the elongation because the carbide formation delay effect.

Cold-rolled steel sheet after annealing heat treatment is hot-dip galvanized at 460 ~ 480 ℃ and reheated to 480 ~ 520 ℃ alloying heat treatment and then cooled to less than 20 ℃ / s cooling rate up to 300 ℃ or less to allow the plating layer to grow stably.

In the alloying heat treatment, when the temperature is lower than 480 ° C., it is difficult to stably grow the plating layer, and when the temperature is higher than 520 ° C., material degradation occurs.

In addition, austenite remaining in the annealing process is transformed into martensite in the cooling process after the alloying heat treatment.

Hereinafter, a high strength cold rolled steel sheet excellent in the above-mentioned resistance ratio ratio and a manufacturing method thereof will be described in comparison with the invention examples and other comparative examples.

Table 1 shows the component ratio of the invention example of this invention and another comparative example.

(Far Fe, Unit: wt%) division C Si Mn P S Al Cr Mo V Ti B
(ppm) N
(ppm) Remarks One 0.06 0.03 2.0 0.01 0.003 0.03 0.20 30 Comparative example 2 0.06 0.03 2.0 0.01 0.003 0.03 0.20 0.20 0.010 30 Inventive Example 3 0.06 0.03 2.0 0.01 0.003 0.30 0.20 10 30 Comparative example 4 0.06 0.03 2.0 0.01 0.003 0.03 0.20 30 Comparative example 5 0.06 0.03 2.0 0.01 0.003 0.03 0.20 0.04 0.015 30 Inventive Example 6 0.06 0.03 2.0 0.01 0.003 0.03 0.20 0.20 0.015 30 Inventive Example 7 0.06 0.03 2.0 0.01 0.003 0.03 0.20 0.015 10 30 Inventive Example

division Hot Rolling Condition Annealing Condition Mechanical properties Organization characteristics Plated
characteristic
Remarks
FDT
(℃) CT
(℃) AT
(℃) TS
(MPa) YS
(MPa) EL
(%) YR
(%) Vm
(vol%) One 900 560 800 563 323 30 57 8 Good Comparative example 2 900 560 800 590 346 28 59 10 Good Inventive Example 3 900 560 800 601 389 26 65 11 Good Comparative example 4 900 560 800 658 366 24 56 16 Good Comparative example 5 900 560 800 612 345 29 56 12 Good Inventive Example 6 900 560 800 620 366 29 59 10 Good Inventive Example 7 900 560 800 627 368 28 59 13 Good Inventive Example

[FDT: finishing hot rolling temperature, CT: coiling temperature, AT: annealing temperature, YS: yield strength, TS: tensile strength, EL: elongation, YR: yield ratio (yield strength / tensile strength), Vm: martensite fraction]

The results of measuring the mechanical properties of the specimens manufactured by the following hot rolling and annealing conditions using the slabs composed as shown in Table 1 are shown in Table 2.

In the manufacturing method, the slab having the alloy composition of Table 1 is reheated at 1250 ° C. for 2 hours or more, followed by finishing hot rolling at a temperature of 900 ° C. (Ar 3 or higher), followed by cold winding (600 ° C.).

The hot rolled steel sheet was pickled and cold rolled to a thickness of 0.65 mm or less. The cold rolled steel sheet was annealed at 800 ° C., and then cooled to 460 ° C., which is overaging at a cooling rate of 25 ° C./sec.

Hot dip galvanizing was carried out by immersing the zinc plating bath at 460 ° C., and after hot dip galvanizing, the alloy was heated to 510 ° C. and cooled to below Ms.

Looking at Table 1 and Table 2, when Mo, Ti is added to the low carbon [C: 0.04 ~ 0.08wt%] base steel, and the addition of one selected from Cr, V, and B, the tensile strength is excellent and the tensile strength of 590 MPa or more is excellent. Strength and elongation of over 28% were secured.

This is because Ti removes solid solution N forming BN and AlN compounds to prevent an increase in yield ratio and hardenable elements promote martensite formation.

And plating property was ensured by restricting Si to 0.1 wt% or less.

Comparative Example 1 did not remove the solid solution N, but due to the low Al content, the grain refinement was insufficient, resulting in a low yield ratio increase. However, the tensile strength did not meet the target level.

In Comparative Example 3, since the solid solution N was not removed, grain refinement occurred due to the formation of AlN and BN, resulting in excessive yield ratio.

Comparative Example 4 also did not remove the solid solution N grains due to the formation of AlN occurred a phenomenon that the yield ratio increases.

A tissue photograph of Inventive Example 2 in Table 2 is shown in FIG. 2.

As shown in FIG. 2, it is confirmed that spherical fine martensite is dispersed in the ferrite grain boundary. Spherical martensite is superior in elongation and brittle in comparison with plate-like martensite.

Therefore, by lowering the content of Si in the steel, which is based on C, Mn, and Al, and adding one selected from Mo, Ti, Cr, V, and B, the austenite remains 10 to 15% during annealing heat treatment. It can be seen that a high strength steel sheet having a tensile strength of 590 MPa or more, an elongation of 28% or more, and a yield ratio of less than 60% can be produced.

Within the scope of the basic technical idea of the present invention, many other modifications are possible to those skilled in the art, and the scope of the present invention should be interpreted based on the appended claims. will be.

1 is a view showing a TiN formation temperature and a tissue photograph in which TiN is formed.

Figure 2 is a tissue photograph showing a high-strength steel sheet having excellent resistance ratio ratio characteristics according to the present invention. (Invention Example 2 in Table 2)

Claims (6)

C: 0.04 to 0.08 wt%, Si: more than 0 wt% or less, Mn: 1.8 to 2.0 wt%, Al: 0.1 to 0.2 wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: over 0, 0.006 wt% or less, Cr: 0.1 to 0.2 wt%, V: 0.01 to 0.05 wt%, B: 0.0005 to 0.0015 wt% It contains at least one selected and the balance is composed of Fe and other unavoidable impurities, High-strength steel sheet having excellent resistance ratio characteristics, characterized in that the microstructure consists of two phases including ferrite and martensite. The method according to claim 1, The microstructure is a high strength steel sheet having excellent resistivity ratio characteristics, characterized in that the ferrite is 85 ~ 90vol%, martensite has a volume fraction of 10 ~ 15vol%. The method according to claim 1 or 2, The martensite is spherical, high strength steel sheet having excellent resistance ratio characteristics, characterized in that finely dispersed in the grain boundary. C: 0.04 to 0.08 wt%, Si: more than 0 wt% or less, Mn: 1.8 to 2.0 wt%, Al: 0.1 to 0.2 wt%, P: 0.015 to 0.020 wt%, S: more than 0.003 wt% or less, Mo: 0.10 to 0.20 wt%, Ti: 0.01 to 0.02 wt%, N: over 0, 0.006 wt% or less, Cr: 0.1 to 0.2 wt%, V: 0.01 to 0.05 wt%, B: 0.0005 to 0.0015 wt% Slabs containing at least one selected and whose balance is composed of Fe and other unavoidable impurities Reheating to 1150 ~ 1250 ℃, then performing the final hot rolling at Ar3 ~ Ar3 + 70 ℃ temperature and wound at 550 ~ 650 ℃ to produce a hot rolled steel sheet; Pickling and hot rolling the hot rolled steel sheet to produce a cold rolled steel sheet; And The annealing heat treatment of the cold rolled steel sheet to retain 10 ~ 15 vol% austenite and hot-dip galvanizing process comprising the step of producing a high-strength steel sheet excellent resistance properties. The method according to claim 4, The annealing heat treatment After the heat treatment in the temperature range of Ar1 ~ Ar3 is a method for producing a high strength steel sheet having excellent resistance ratio characteristics, characterized by cooling to a temperature range of 400 ~ 500 ℃ at a cooling rate of 5 ~ 30 ℃ / sec. The method according to claim 5, The temperature range of the Ar1 ~ Ar3 is 760 ~ 840 ℃ manufacturing method of high strength steel sheet having excellent resistance ratio characteristics.

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