NON HEAT-TREATED STEEL AND MANUFACTURING METHOD THEREOF

Hereinafter, the present invention is described therein that are directionally. The, in the present invention specifically described publicly known techniques or configuration related description is the subject matter of invention description if breach of haze can be decided to be dispensed will.

In the present invention which is defined as the ability to carry terms and terms of the user, such as operator depending on intended or which said first and second definition describing the content throughout the specification based on the present invention will been commanded.

Improving workability Manufacturing method

The manufacturing method of the present invention are described in terms of one of improving workability. Figure 1 of the present invention revealing the manufacturing method capable of improving workability according to embodiments are disclosed. 1 also said reference surface, said manufacturing method capable of improving workability (S10) the reheating step semi number article; (S20) hot forging; and cooling step (S30); without using a tool. More particularly, the manufacturing method capable of improving workability (S10) carbon (C): 0. 1 - 0. 2% by weight, manganese (Mn): 0. 3 - 3. 0% by weight, chromium (Cr): 0. 1 - 1. 5% by weight, silicon (Si): 0. 05 - 0. 3% by weight and contains residual iron (Fe) and other impurities including semi number heating article material; said article at a temperature of 750 °C provided 800 °C (S20) reheat semi number by forging material number bath hot forging step; and cooling said forging material (S30); without using a tool.

Hereinafter, the present invention according to manufacturing method capable of improving workability detailed processes to other.

(S10) semi number article re-heating step

Said step carbon (C), manganese (Mn), chromium (Cr), silicon (Si) and contains residual iron (Fe) and other impurities including heating the article material semi number are disclosed.

Hereinafter, detailed content for inclusion in said semi number refrigerating component to substrate.

Carbon (C)

(C) said carbon steel strength portion which is effective important element are disclosed. Austenitic employed in a quenched martensitic structure formed in the base. Increasing amount of quenched so as to improve the carbon outer quenching possibility makes other. Said carbon, iron (Fe), chromium (Cr), molybdenum (Mo), and vanadium (V) combined with an element such as formed by carbide, steel strength and hardness and the base.

In one embodiment said entire article relative to the weight of said carbon semi number 0. 1 - 0. 2% by weight multiple myelomas are included. When a steel can be said range exhibiting excellent high temperature strength. Said carbon 0. 1% by weight of the present invention when a tensile strength and hardness less than mechanical secure strength difficult for, 0. 2% by weight may cause a decrease in processability when greater than 2000.

Manganese (Mn)

Said manganese (Mn) is said to enhance the strength except the baking at a high temperature aluminum alloy casting with the object of increasing the multiple myelomas are included. In particular, some of the high manganese steel and said inside, said steel part is critical to the formation of sulfur contained in combination with an ingot non-gold MnS, stretching the long in the directions of deviation in said MnS is a flexible plastic cutting workability can be improved. However Mns and desorbing it on the inside of the river in the form of a pad while it is that fusion point chemical compound further comprises a step of returning and reduced formation of FeS billion number. Acid resistant steel floor plate but are fine perlite and the ferrite inhibiting oxidation by a yield strength of the base.

In one embodiment said semi number 0 manganese said relative to the weight of the entire article. 3 - 3. 0% by weight multiple myelomas are included. Said range when a cutting workability, and casting can be excellent. Said manganese 0. 3% by weight and its added amount less than inverted triangular screw, 3. 0% by weight greater than when, cracks and induce strain capable of quenching.

Chromium (Cr)

Said chromium (Cr) ferrite stabilizing element, fast diffusion of solute C-a Mn steel when added to the fine particle size carbon effect disturbance affecting the other.

In one embodiment said chromium relative to the weight of said entire article semi number 0. 1 - 1. 5% by weight multiple myelomas are included. When a particle size range of said micronized effect is, ductility can be improved. Said chromium 0. 1% by weight less than which exerts its effect when a number added as difficult, 1. 5% by weight greater than toughness except when said pressure drop, processability or blood [sak characteristic can be reduced disclosed.

Silicon (Si)

Said silicon (Si) SiO residual number that the Pig iron with a carbonic₂ The elder brother it stands such as compound is employed in a ferrite without, have a great impact on steel do not affect the mechanical properties. In addition, it acts as a softening resistance in tempering by powerful deoxidation number increase effect disapproval.

In one embodiment said silicon is the entire article relative to the weight of said semi number 0. 05 - 0. 3% by weight multiple myelomas are included. When a base in said range ferrite strengthening effect can be excellent. Said silicon 0. 05% by weight and less than added when a inverted triangular screw, 0. 3% by weight greater than the toughness when steel sheets whose separator is subsequently shaped hatch forging and can be.

Another embodiment of the present invention said copper (Cu) semi number article: exceeds 0 0. 5 weight % hereinafter, nickel (Ni): exceeds 0 0. 5 weight % hereinafter, titanium (Ti): exceeds 0 0. 5 weight % hereinafter, niobium (Nb): exceeds 0 0. 01 weight % hereinafter, vanadium (V): exceeds 0 0. 01% weight % hereinafter, calcium (Ca): exceeds 0 0. 005% hereinafter by weight, magnesium (Mg): exceeds 0 0. 005% hereinafter by weight, antimony (Sb): exceeds 0 0. 05 weight % hereinafter and tin (Sn): exceeds 0 0. 05 weight % hereinafter further comprises one or more can be.

Copper (Cu)

Said copper (Cu) exhibit a high-strengthening effect is effect may have strength and hardness. In addition ready and in seawater corrosion resistance can be significantly increased.

In one embodiment said copper number exceeds 0 0 the entire article relative to the weight of said half. 5 weight % hereinafter can be included. When a brittleness of said range and while preventing hot workability, strength and hardness and can be improved, can be excellent in corrosion resistance. For example, 0. 3 - 0. 5% by weight can be included.

Nickel (Ni)

Said nickel (Ni) is effected so as to fine ferrite steel and austenitic high well is the nonskid base enhancement can be included. said nickel is cured with excellent, and austenite stabilizing element acting as large steel for heat treatment can be made hereinafter. In addition, steel weldability and malleability of damage not enhancing toughness at low temperatures. said nickel is slow diffusion of carbon and nitrogen in workability of make a chest prevents the coefficient, capable of shearing modulus and this rate is improved.

In one embodiment said nickel is said semi number relative to the weight exceeds 0 0 total article. 5 weight % hereinafter can be included. Said range when a rigid steel, can be superior weldability and toughness at low temperatures.

Titanium (Ti)

Said titanium (Ti) oxygen (O), nitrogen (N), sulfur (S) and hydrogen (H) that is superior in affinity silica powder or the like, can be included to be for denitrification and desulfurization. The titanium carbide forming said rubber composition having excellent than chromium, stainless steel or cutting tool steel improved and a grain refiner has excellent even other. In addition to other metal element for forming compounds also precipitation-hardenable effect is disclosed.

In one embodiment said number exceeds 0 0 relative to the weight of the titanium said half the entire article. 5 weight % hereinafter can be included. Said range has excellent when a austenitic grain refiner can be.

In one embodiment of the present invention said copper (Cu) semi number article, nickel (Ni), and titanium (Ti) is, formula 1 satisfies the relation can be included to be:

[Formula 1]

0. 01 ≤ + + ≤ 0. 5

(Said type 1 in, said Cu, Ni, and Ti is used in said semi number article copper (Cu), nickel (Ni), and titanium (Ti) (unit:% by weight) content of are disclosed.)

Said copper (Cu), nickel (Ni), and titanium (Ti) is set on when a of said type 1, of the present invention can be elongation and exhibiting excellent high temperature strength.

Niobium (Nb)

Niobium (Nb) is provided to transmit said determined grain can be included. Said niobium may, for precipitating fine niobium carbonitride to boundaries to determined action capable of miniaturizing a pinned (pinning).

In one embodiment said niobium may number 0 0 entire article relative to the weight exceeds said semi. 01 weight % hereinafter can be included. Said range has excellent when a can be a grain refiner.

Vanadium (V)

Vanadium (V) upon cooling of said hot forging mainly carbide, carbonitride is formed by ferrite enhances precipitation strengthening can be included.

In one embodiment said vanadium is greater than 0 0. 01% weight % hereinafter can be included. Said range when a precipitation strengthening effect can be excellent.

Calcium (Ca)

The fine silica powder and calcium (Ca) said element, as well as generates the blood [sak characteristic soft oxide, to form a composite sulfide MnS-based inclusions solid solution, re-by performance, MnS based inclusions when hot forging effect stretch billion number flow tides.

In one embodiment said total number exceeds said article relative to the weight of the calcium carbonate may be semi 0 0. 005% hereinafter weight can be included. Generating said range when a soft oxide can be steel excellent in machinability.

Magnesium (Mg)

The fine silica powder and said magnesium (Mg) element, Mg oxide formed on the substrate. MnS based inclusions Mg oxide is constant output voltage, so that the constant output voltage based inclusions MnS precipitation nuclei, longevity and precipitation site, MnS-based inclusions uniform, finely dispersed in the sensor is disclosed. In addition, the MnS-based inclusions Mg solid solution to form a composite sulfide, re-by performance, at the time of hot forging effect stretch billion number MnS based inclusions flow tides. , the MnS Mg fine dispersion based inclusions and anisotropic of effective element are disclosed.

In one embodiment said number exceeds 0 0 relative to the weight of the magnesium said half the entire article. 005% hereinafter weight can be included. Said range when a fine dispersion based inclusions can be effective in diminishing MnS and anisotropic.

Antimony (Sb)

The antimony (Sb) formed within said substrate austenitic Sb oxide, and electrolytic formation (grain boundary) and because of the number to prevent major mouth orgin billion billion number anti deficiency can be.

In one embodiment said number exceeds 0 0 relative to the weight of said antimony is semi entire article. 05 weight % hereinafter can be included. Said range when a surface effect and a grain refiner having excellent deficiency can be.

Tin (Sn)

Said tin (Sn) of promoting the corrosion of steel and can be a copper-chrome-billion number.

In one embodiment said annotations are relative to the weight of said entire article exceeds 0 semi number 0. 05 weight % hereinafter can be included. Said range when a corrosion can be excellent.

Phosphorus (P) and sulfur (S)

In one embodiment said semi number article includes, as unavoidable impurities, phosphorus (P) and sulfur (S) further comprises at least one can be.

Said sulfur (S) and phosphorus (P) or contribute to increasing the strength is part, lowering low temperature impact toughness as low mode is representative element content can comprise now. In one embodiment said sulfur (S) and phosphorus (P) content of total number exceeds 0 0 contact with the respect to the article. 01 weight % hereinafter can be said.

In one embodiment said aforementioned components and contains residual iron (Fe) semi number article, and other unavoidable impurities formed of a melt, continuous casting process can be number into a predetermined shape by using high pressure liquid coolant. More particularly, said ladle furnace (Ladle Furnace) contained in each component content involved in the regulation of molten, perform deoxidation and desulfurization process, vacuum degassing facility (Vacuum Degasing) number included in gas content after molten there, through continuous casting process into a specific shape to metal mold halves the number article number can be high pressure liquid coolant. In one embodiment said number article comprises a billet (billet) or [pul roentgen per hour at one meter (bloom) can be in the form of a half.

In one embodiment said material heating said article 1150 °C-a 1250 °C semi number is heated at a temperature can be done via the disclosed. Said re-heating temperature is less than 1150 °C, door number hot forging processability when reduced flow tides. Said 1250 °C reheat temperature is exceeded, further comprises a step of austenitic steel door that is difficult to secure strength number to number bath novel measured disclosed.

(S20) Hot Forging

Said step number by a step number bath hot forging of semi re-heating said article forgings are disclosed. In one embodiment said hot forging, hot forging at a temperature of 750 °C provided 800 °C said reheating semi number article number to a forging material tank are disclosed.

Said hot forging temperature range (or hot deformation finishing temperature range) is, in the present invention continuous tax the tie [thu which it carries on shoulder to prevent the formation of cementite, realize the near completion temperature (A1) is explosively nucleation to create deformation in the embodiment as follows. Said article during hot forging at temperatures less than 750 °C semi number, the stainless steel sheets whose edge (edge) tissue can be generated. In addition, article during hot forging said semi number exceeds 800 °C, crystal grains growing serves a door number inhibiting toughness at low temperatures and flow tides.

(S30) cooling step

Said step includes cooling said forging material are disclosed. In one embodiment said cooling, said forging material difference 1 cooling; and cooling said 1 secondary cooling and in which material can be a 2 difference.

Upon cooling of said forgings, such as bainite fraction of reduced or perlite cooling end temperature is raised the potential tissue interval is increased so as to decrease strength and movement acting maintains the obstacle, (cementite) and ferrite (ferrite) modified from that of the coarse sprayable concentrates the deficiency such as to form the void and 0.72 site is provided to the user can be around 460. Suitable 1 cold temperature difference elongation compensation is necessary disclosed.

In one embodiment said 1 difference cooling said forging material can be cooled to a temperature °C 600 provided 500 °C. 1 difference in said temperature conditions at the time of cooling, bainite fraction is increased, can be elongation and excellent processing properties.

In one embodiment said 1 difference cooling a cooling rate of 1/s 5 °C/s provided 12 °C secondary cooling can. Said in a magnetron, perlite tissue generation can number billion.

In one embodiment said 2 difference cooling said 1 secondary cooling and in which material can be cooled to a temperature °C 550 provided 350 °C. The secondary cooling 2 when said range conditions, said 1 secondary cooling in pearlite in the tissue generation number billion can be enhances the bainite structure changing the final lecture is superior.

In one embodiment said 2 difference cooling, a cooling rate of 10 °C/s provided 20 °C/s 2 secondary cooling can. In said cooling rate, grain growth can be ensure excellent strength and impact toughness while number billion. For example 15 °C/s provided 20 °C/s can be cooling a cooling rate of 2 difference.

Improving workability

Said manufacturing method capable of improving workability by another aspect of the present invention the number prepared by the battery modules are disclosed.

In one embodiment said qualitative river non carbon (C): 0. 1 - 0. 2% by weight, manganese (Mn): 0. 3 - 3. 0% by weight, chromium (Cr): 0. 1 - 1. 5% by weight, silicon (Si): 0. 05 - 0. 3% by weight and contains residual iron (Fe) and other unavoidable impurities comprise. The component comprising the battery modules included, the described method are the same as the aforementioned number tank, dispensed description to each other.

Another embodiment of the present invention said copper (Cu) non qualitative river: exceeds 0 0. 5 weight % hereinafter, nickel (Ni): exceeds 0 0. 5 weight % hereinafter, titanium (Ti): exceeds 0 0. 5 weight % hereinafter, niobium (Nb): exceeds 0 0. 01 weight % hereinafter, vanadium (V): exceeds 0 0. 01% weight % hereinafter, calcium (Ca): exceeds 0 0. 005% hereinafter by weight, magnesium (Mg): exceeds 0 0. 005% hereinafter by weight, antimony (Sb): exceeds 0 0. 05 weight % hereinafter and tin (Sn): exceeds 0 0. 05 weight % hereinafter further comprises one or more can be.

Copper (Cu) of the present invention in one embodiment said battery modules, nickel (Ni), and titanium (Ti) is, formula 1 satisfies the relation can be included to be:

[Formula 1]

0. 01 ≤ + + ≤ 0. 5

(Said type 1 in, said Cu, Ni, and Ti is used in said battery modules copper (Cu), nickel (Ni), and titanium (Ti) (unit:% by weight) content of are disclosed.)

Said copper (Cu), nickel (Ni), and titanium (Ti) is set on when a of said type 1, of the present invention can be elongation and exhibiting excellent high temperature strength.

In one embodiment said qualitative river non tensile strength (TS): 660 mpa or more, yield strength (YS): 470 mpa and an elongation (El): be a 30% or more. For example tensile strength (TS): 660 - 750 mpa, yield strength (YS): and an elongation of 470 - 580 mpa (El): implementation being 30% -37%.

Non specific alloy component and cooling conditions of the present invention qualitative river to the perlite tissue generation number is superior to steel billion final tissue enhances the bainite structure, mechanical properties such as excellent quenching and the vehicle number [...] vehicle can be contributing to the rubber. In addition processability and durability required automobile parts required and preventing deformation properties and excellent elongation [...] number, process for preparing number or a number can be [...] ts. The river kind number can be a high pressure liquid coolant can be cost effect can be [...] number increase production efficiency.

Hereinafter, a structure and operation of the invention of the present invention preferred embodiment seen through the more detailed the on-sensors other. But, this is one example of the present invention to which the present invention is preferably [...] number as the number one interprets any meaning is capable of free.

In the embodiment and Comparison example

In the embodiment 1 - 2

Components such as and to table 1, contains residual iron (Fe) and other impurities including semi number articles, such as the reheating temperature to table 2 is re-heated and then, table 2 embodiment a number was a hot forging at a temperature hot forged to forgings high pressure liquid coolant. Then, a table 2 1 2 cooling about said forgings to specimen number was high pressure liquid coolant cooling and difference difference embodiment of improving workability.

Comparison example 1

Components such as for table 1 and content by applying half the number article, such as the reheating temperature to table 2 is re-heated and then, table 2 embodiment hot forging temperature by cooling a hot forged to make temperature was high pressure liquid coolant specimen number of improving workability.

Mechanical properties evaluation

Said in the embodiment 1 - 2 and comparison to table 3 measures the mechanical properties except the shown embodiments.

Table 3 said reference surface, of the present invention in the embodiment 1 - 2 is, for example comparison than tensile strength, yield strength and elongation his car to 1:1 by weight. Generally, in the case of copper (Cu) 0 said. 5% or more by weight added, or reduced elongation hot-shortness the same substrate.

This, copper (Cu) of chromium (Cr) by adding said solute by fine effect can be obtained as well as a layered interval so as perlite, copper (Cu) iron (Fe) high temperature oxidation rate of 20 weight than small, steel branches all during the machining of hot forging, penetrate into the second base steel, nickel (Ni) and titanium (Ti) in the present invention by adding further, comparison example sample capable of improving workability improving phenomenon maximum strength, toughness and an elongation of the rectifier to determine the other.

Figure 2 said in the embodiment 1 - 2 and comparison example photograph indicating the center of the microstructure are disclosed. the reference 2 also, in the embodiment 1 - 2 embodiment of the present invention in the case of a hot deformation temperature in a hot forging, forming microstructure is fine when the dominant bainitic tissue, fraction of fine pearlite tissue in this case can be formed cylindrical, cementite ferrite is generated were checking has not been altered.

For the embodiment of the present invention simple modifications to change by person with skill in the art coagulants are hereinafter can be, such deformation or modification of the present invention can be both included in the region of the branch.