40 results about "Bake hardening" patented technology

The invention relates to the technical field of aluminum alloy materials, in particular to an Al-Mg-Si alloy and a preparation method thereof, a beta ''-phase aluminum alloy and an aluminum alloy plate for an automobile. The Al-Mg-Si series alloy disclosed by the invention is prepared from the following chemical components in percentage by mass: 0.4 percent to 0.7 percent of Si, 0.5 percent to 0.6 percent of Fe, 0.1 percent to 0.25 percent of Cu, 0.4 percent to 0.8 percent of Mn, 0.5 percent to 0.8 percent of Mg, 0 to 0.3 percent of Zn, 0 to 0.2 percent of Ti, 0 to 0.15 percent of Cr, 0.05 percent to 0.2 percent of V, 0.05 percent to 0.2 percent of Mo and 94 percent to 98 percent of Al. The yield strength of the Al-Mg-Si alloy subjected to baking hardening treatment at 170-200 DEG C is greater than or equal to 200MPa; and the yield strength of the Al-Mg-Si alloy which is not subjected to baking hardening treatment at 170-200 DEG C is less than or equal to 130 MPa. According to the Al-Mg-Si alloy provided by the invention, impurity elements such as Fe and Mn can be utilized, so that recycling of the aluminum alloy with high impurity content is realized; and the initial yield strength is low, the yield strength is high after baking hardening treatment, and the stamping forming performance and the baking performance are good.

The invention discloses a 980MPa-grade steel plate with a high bake hardening value, which contains Fe and inevitable impurities, and also contains the following chemical elements in percentage by mass: 0.15-0.25% of C; 0.5 to 1.7 percent of Si; mn: 1.50 to 2.50%; 0.03% to 0.80% of Al; 0 < B < = 0.001%; the 980 MPa grade steel plate does not contain Nb, V, Ti, Cr and Mo elements. The microstructure of the 980 MPa grade steel plate comprises at least one of retained austenite, martensite, tempered martensite and partition martensite, and the total area proportion of the retained austenite, the martensite, the tempered martensite and the partition martensite is not lower than 50%. The dislocation density of the martensite, the tempered martensite and the partition martensite is not lower than 0.7 * 10 < 15 > / m < 2 >.

This invention relates to the field of aluminum alloy materials technology, specifically to a low-zinc-content 6-series aluminum alloy sheet and its manufacturing method. The components and their weight percentages in the low-zinc-content 6-series aluminum alloy sheet are as follows: Si content 0.90-1.20%, Mg content 0.45-0.65%, Cu content 0.12-0.20%, Zn content 0.05-0.10%, Fe content ≤0.28%, Mn content 0.02-0.20%, Cr content ≤0.10%, Ti content ≤0.15%, containing at least one of In, Cd, La, and Ce, and the total content of In, Cd, La, and Ce is 0.01-0.10%; the content of a single impurity ≤0.03%; the total content of other impurity elements ≤0.1%; and the balance is Al. This 6-series aluminum alloy sheet, with a low zinc content (Zn ≤0.10%), possesses excellent formability, high bake hardening value, and high batch stability.

The invention relates to the technical field of metal materials, in particular to a 5-series aluminum alloy plate with low-temperature baking hardening response and a preparation method of the 5-series aluminum alloy plate. The content of Zn is 1.5%-3.5%; the content of Cu is 0.3%-1.2%; the content of Mn is 0.1 to 0.3 percent; the content of Cr is 0.03 to 0.15 percent; the content of Zr is 0.05 to 0.15 percent; the content of Ti is 0.01 to 0.10 percent; si content is less than or equal to 0.2%; fe content is less than or equal to 0.25%; the La content is less than or equal to 0.2%; the Ce content is less than or equal to 0.2%; the content of Yb is less than or equal to 0.2%; the balance is Al; the bake hardening response efficiency function phi BH of the 5-series aluminum alloy plate is 0.15-1.2; the steel plate has low yield strength, high elongation, high formability and high sinking resistance, and baking varnish hardening is guaranteed.

The invention discloses a 1180MPa-grade steel plate with a high bake hardening value, which contains Fe and inevitable impurities, and also contains the following chemical elements in percentage by mass: 0.17-0.27% of C, 0.18-0.18% of Cr, 0.18-0.18% of Mo, 0.18-0.18% of Mo, 0.18-0.18% of V, 0.5 to 1.7 percent of Si; mn: 2.3 to 3.0%; 0.02 to 0.90 percent of Al; 0 < B < = 0.003%; and Al + Si < = 2.00%; the microstructure of the 1180MPa-grade steel plate comprises at least one of martensite, tempered martensite and partition martensite with the area ratio not lower than 50%, and the dislocation density of the martensite, the tempered martensite and the partition martensite is not lower than 0.8 * 10 < 15 > / m < 2 >. The invention further discloses a manufacturing method of the steel plate. The manufacturing method comprises the steps of smelting and continuous casting; hot rolling; pickling and cold rolling; and continuously annealing.

The invention relates to the technical field of alloys, in particular to a high-toughness corrosion-resistant industrial aluminum alloy for a new energy automobile and a preparation method of the high-toughness corrosion-resistant industrial aluminum alloy. According to the aluminum alloy, magnesium-lanthanum co-doped calcium-phosphorus particles are introduced to serve as a sacrificial phase, aluminum-zirconium and aluminum-erbium dispersed phases are combined to form a stable framework, and the solute cluster gradient is constructed in the thickness direction of a plate through a non-isothermal pre-aging process. The preparation method comprises the steps of intermediate alloy preparation, smelting and casting, homogenizing heat treatment, rolling, solid solution quenching, non-isothermal pre-aging and pre-stretching forming. The alloy is excellent in comprehensive performance, corrosion resistance and stress corrosion cracking resistance are remarkably improved while high strength and good bake hardening response are guaranteed, and the alloy is particularly suitable for new energy automobile body structural parts.

The invention discloses a stable manufacturing method of automobile 220MPa-grade cold-rolled bake-hardened steel with excellent sinking resistance, and belongs to the field of material forming. According to the stable manufacturing method provided by the invention, the 220MPa-grade cold-rolled bake-hardened steel for the automobile is controlled to comprise the following chemical components in percentage by mass: 0.0015 to 0.0025 percent of C, 0.03 to 0.10 percent of Si, 0.50 to 0.65 percent of Mn, 0.055 to 0.065 percent of P, 0.008 to 0.015 percent of Ti, 0.015 to 0.060 percent of Al, less than or equal to 0.015 percent of S, less than or equal to 0.0030 percent of O and less than or equal to 0.0020 percent of N, and the content ratio of Si to Mn is 0.06 to 0.15; the bake hardening value of the manufactured steel is 48-60 MPa, and the steel has stable and excellent sinking resistance.

This invention relates to the field of automotive steel technology, specifically to a 220MPa grade low-wavyness hot-dip galvanized bake-hardening steel sheet, its manufacturing method, and its application. The main chemical elements are C, Si, Mn, P, Als, Nb, N, and S. The dissolved C content in the steel is 0.0008%–0.0015%, with the balance being iron and unavoidable impurities. This invention also discloses a manufacturing method for the above-mentioned bake-hardening hot-dip galvanized steel sheet, including steelmaking, continuous casting, slab heating, hot rolling, laminar flow cooling, pickling, hot-dip galvanizing, and leveling processes. The surface waviness Wsa of the produced steel sheet after 5% forming is... (1‑5) ≤0.35μm, increase in surface waviness ΔWsa (1‑5) With a thickness of ≤0.05μm and a yield strength of 220~280MPa, it meets the application requirements of water-based no-primer coating process for automotive exterior body panels.

This invention relates to a cold-rolled steel sheet with high bake hardening and excellent bendability after bake hardening. It has a specified composition, containing 20%–70% ferrite and more than 30% tempered martensite by area ratio, with the total ferrite and tempered martensite exceeding 90%. A 30μm × 30μm microstructure image obtained by photographing the microstructure at 2000x magnification is placed in an xy coordinate system with the thickness direction as the x-axis and the rolling direction as the y-axis. The microstructure image is then divided into 1024 segments along the x-axis and 1024 segments along the y-axis to form 1024 × 1024 segmented regions. The values ​​in each segmented region are set to "1" if the microstructure is ferrite and "0" otherwise, and then converted to 2-grayscale to create a two-dimensional image. The heterogeneity α obtained by performing a two-dimensional discrete Fourier transform on the two-dimensional image is 1.20 or less.

The present application belongs to the technical field of recycled aluminum alloy, and discloses a composite treatment method for modifying Fe-rich phase of 6016 recycled aluminum alloy and enhancing paint-baking hardening response. The composite treatment method comprises the following steps: S1) performing Sr, Cr and Sn multi-element micro-alloying treatment on remelted 6016 aluminum alloy; then preparing the micro-alloyed melt into an ingot; S2) performing heat preservation homogenization treatment, hot rolling, cold rolling, solid solution treatment, natural aging, paint baking treatment on the ingot to obtain the recycled aluminum alloy. The method realizes the conversion of β-Fe phase to α-Fe phase in the 6016 recycled aluminum alloy, effectively modifies the coarse long needle-shaped Fe-rich phase into fine Chinese character-shaped Fe-rich phase, effectively suppresses the negative influence of natural aging, and enhances the paint-baking hardening increment. The recycled aluminum alloy after multi-element micro-alloying treatment has excellent mechanical properties, significantly reduces the harm of impurity element Fe to the 6016 recycled aluminum alloy, and realizes high-quality utilization of the recycled aluminum alloy.

The invention relates to 780MPa-grade cold-rolled dual-phase steel with high bake hardenability, high yield ratio and high elongation and a production method of the 780MPa-grade cold-rolled dual-phase steel. The steel comprises the following chemical components in percentage by weight: 0.08 to 0.10 percent of C, 1.95 to 2.05 percent of Mn, less than or equal to 0.005 percent of S, less than or equal to 0.020 percent of P, less than or equal to 0.10 percent of Si, 0.030 to 0.070 percent of Als, 0.25 to 0.35 percent of Cr, 0.15 to 0.25 percent of Mo, 0.040 to 0.065 percent of Nb + Ti and the balance of Fe and inevitable impurities. The produced cold-rolled strip steel is good in surface quality, has the characteristics of high bake hardenability, high yield ratio and high elongation, and meets the increasingly stringent supply requirements of domestic and overseas advanced main engine plants on the 780MPa-grade dual-phase steel.

An aspect of the present invention is to provide a cold-rolled steel sheet and a manufacturing method thereof. A preferred aspect of the present invention is to provide a cold-rolled steel sheet having excellent low-temperature bake hardenability and room-temperature aging resistance and a manufacturing method thereof.

The invention relates to a hot-rolled flat steel product, the microstructure of which can comprise at most 9% residual austenite and at most 11% martensite, the remainder being bainitic ferrite with precipitates in the form of carbides, nitrides and / or carbonitrides, and the flat steel product has a tensile strength Rm of at least 950 MPa, a yield strength Re of at least 670 MPa, and a bake-hardening effect BH of at least 40 MPa. The invention also relates to a method for producing the flat steel product.

The present invention provides a bake hardening type hot-dip galvanized steel sheet having excellent chipping resistance and a method for manufacturing the same. The bake hardening type hot-dip galvanized steel sheet of the present invention contains, in terms of weight %, C: 0.0001-0.005 %, Mn: 0.1-1.2 %, Si: 0.02 % or less (except 0 %), P: 0.01-0.04 %, S: 0.01 % or less (except 0 %), N: 0.01 % or less (except 0 %), sol.Al: 0.01-0.06 %, Nb: 0.003-0.015 %, B: 0.0005-0.0035 %, Cr: 0.01-0.1 %, Mo: 0.005-0.05 %, Ti: 0.003 % or less (except 0 %), the balance of Fe and inevitable impurities, and satisfies the following relation 1 to relation 2, the fine structure of the hot-dip galvanized steel sheet is ferrite single phase, and satisfies the following relation 3.

A kind of 6451 aluminum alloy plate based on dynamic diffusion field regulation belongs to the field of aluminum alloy digital manufacturing technology.The raw material is melted and refined into ingot according to set composition, then the ingot is cut and milled after being put into heat treatment furnace for homogenization treatment, the ingot after homogenization treatment is cooled to hot rolling temperature for a period of time and then hot rolling starts.After hot rolling, the obtained hot rolled plate is cold rolled and intermediate annealed, then cold rolled to the thickness of final product plate, the obtained cold rolled plate is treated by solid solution, water quenching and then pre-aging treatment, the finished plate is obtained, the finished plate is treated by baking finish, and the final plate is obtained.The present application strictly controls the preparation process, ensures the plate under the premise of low initial yield strength, realizes high baking hardening performance, and is better suitable for automobile structural parts with high forming requirement, high strength requirement and high impact performance.

The invention discloses a production method of bake-hardening steel for a passenger car trunk outer plate, and belongs to the technical field of ferrous metallurgy steelmaking processes. The method comprises the following procedures of steelmaking, hot rolling, cold rolling and annealing. The casting blank comprises the following chemical components in percentage by mass: 0.0010% < = C < = 0.0040%; less than or equal to 0.03% of Si; 0.30% or less of Mn; 0.020% < = P < = 0.050%; s < = 0.008%; alt is greater than or equal to 0.020%; the bake-hardened steel with the mechanical properties meeting the requirements that the yield strength is 180-240 MPa, the tensile strength is 290-390 MPa, the ductility is larger than or equal to 34.0%, r90 is larger than or equal to 1.5, n90 is larger than or equal to 0.16, and BH2 is larger than or equal to 30 MPa can be obtained by controlling the technological parameters of the steelmaking procedure, the hot rolling procedure, the annealing procedure and the like.

The invention discloses ultra-low carbon bake hardening steel with a short process and a long aging period and a production method of the ultra-low carbon bake hardening steel. The ultra-low carbon bake hardening steel comprises the following chemical components: 0.001 to 0.0035 percent of C, less than or equal to 0.03 percent of Si, 0.1 to 0.6 percent of Mn, less than or equal to 0.005 percent of S, 0.020 to 0.065 percent of Als, 0.005 to 0.02 percent of Nb, 0.0003 to 0.001 percent of B, 0.05 to 0.15 percent of Cu, less than or equal to 0.0035 percent of N, 0.0008 to 0.0015 percent of solid solution C and the balance of iron and inevitable impurities. The production method comprises the working procedures of smelting, double-roller thin strip cast rolling, cold rolling, continuous annealing and leveling. The method comprises the following steps: strictly controlling the components of molten steel, cooling and solidifying between casting rollers to form a cast strip of 3-6 mm, rolling to obtain a hot-rolled coil of 2-5 mm after online one-pass hot rolling and flattening, carrying out cold rolling to obtain a cold hard coil of 0.5-1.0 mm, and accurately controlling a continuous annealing process to obtain the bake-hardened steel of which the yield strength is 235-280 MPa, the tensile strength is 320-400 MPa, the elongation A80 is greater than or equal to 38%, the bake-hardening value BH2 is greater than or equal to 45 MPa, the r value is greater than or equal to 2.0 and the work hardening index n is greater than or equal to 0.2. In addition, the steel does not have natural aging after being stored for 6 months in summer, and shows good storage stability.

The invention relates to the technical field of aluminum alloy material and plate forming processing, in particular to a 6-series aluminum alloy material suitable for an automobile outer covering part and a preparation method of the 6-series aluminum alloy material. The content of Mg is 0.60 to 0.90 percent; the content of Cu is 0.25 to 0.35 percent; the content of Zn is 0.05 to 0.10 percent; the content of Mn is 0.05 to 0.30 percent; the content of Fe is less than or equal to 0.20%; the content of Zr is 0.05 to 0.15 percent; the content of Ce is 0.05 to 0.15 percent; the content of La is 0.05 to 0.15 percent; the content of Ti is less than or equal to 0.10%; the single content of other impurity elements is less than or equal to 0.03%; the total content of other impurity elements is less than or equal to 0.15%; the material has excellent formability, bake hardening response, r value / n value and extreme pressure property.

Disclosed in the present invention is a 980 MPa-grade steel plate having a high bake hardening value, comprising Fe and inevitable impurities, and further comprising the following chemical elements in percentage by mass: 0.15-0.25% of C, 0.5-1.7% of Si, 1.50-2.50% of Mn, 0.03-0.80% of Al, and greater than 0% and less than 0.001% of B. The 980 MPa-grade steel plate does not contain Nb, V, Ti, Cr, and Mo elements. The microstructure of the 980 MPa-grade steel plate has: (1) retained austenite; and (2) at least one of martensite, tempered martensite, and partitioned martensite, wherein the total area proportion of the retained austenite and the at least one of martensite, tempered martensite, and partitioned martensite is not less than 50%, and the dislocation density in the martensite, tempered martensite, and partitioned martensite is not less than 0.7×1015 / m2.

Disclosed in the present invention is a 1180 MPa-grade steel plate having a high baking hardening value. The steel plate comprises Fe and inevitable impurities and further comprises the following chemical elements in percentage by mass: C: 0.17-0.27%, Si: 0.5-1.7%, Mn: 2.3-3.0%, Al: 0.02-0.90%, and 0 < B ≤ 0.003%, wherein Al + Si ≤ 2.00%. The microstructure of the 1180 MPa-grade steel plate has at least one of martensite, tempered martensite, and partitioned martensite having an area proportion of not less than 50%, and the dislocation density in the martensite, the tempered martensite, and the partitioned martensite is not less than 0.8×1015 / m2. Further disclosed in the present invention is a method for manufacturing the steel plate, comprising the steps of: smelting and continuous casting; hot rolling; pickling and cold rolling; and continuous annealing.

The invention provides cold-rolled bake-hardened steel with low waviness and excellent aging resistance and a production method thereof, the cold-rolled bake-hardened steel comprises the following components: C, Si, Mn, Als, P, S, N, Nb, Ti and B, and excess carbon content [C] = C-Nb / 7.74, the average room temperature during production is more than 15 DEG C, and [C] is controlled to be 0.0004-0.0012 wt%; and when the average temperature of room temperature during production is less than or equal to 15 DEG C, [C] is 0.0004-0.0015 wt%. Compared with the prior art, through low-carbon and niobium microalloying and recrystallization annealing, the annealing time is 60-100 s at 810-830 DEG C, the dew point temperature requirement in the whole annealing process is controlled to be-45 DEG C or below, anisotropy is reduced, and bake hardening (BH value) and aging resistance are balanced; through component and process design, toughness is improved, surface corrugation after stamping is avoided, and aging resistance is improved.

The present invention provides: a galvanized steel sheet which has excellent high strength, excellent high bake hardening, excellent collision resistance, and excellent crack resistance; and a method for producing the same. This galvanized steel sheet contains, in mass%, 0.150-0.450% of C, 0.50-3.00% of Si, 1.50-4.00% of Mn, 0.100% or less of P, 0.0200% or less of S, 0.100% or less of Al, 0.0100% or less of O, and 0.0100% or less of N, wherein: the amount of diffusible hydrogen in the steel is 0.60 ppm by mass or less; the difference in yield strength before and after processing and baking is 300 MPa or more; and the microstructure in the range from 1 / 8-3 / 8 the sheet thickness satisfies, in area%, (i) the total of tempered martensite and bainite is 55-90%, (ii) fresh martensite having an aspect ratio of 4 or more is 30% or less, (iii) retained austenite is 5-30%, and (iv) the ratio of the area ratio of retained austenite after a sub-zero treatment to the area ratio of retained austenite before the sub-zero treatment is 0.95 or less.

The invention discloses a 1470MPa-grade steel plate with a high bake hardening value, which contains Fe and inevitable impurities, and also contains the following chemical elements in percentage by mass: 0.21-0.31% of C, 0.21-0.32% of Cr, 0.35-0.35% of Mo, 0.35-0.35% of Mo, 0.35-0.35% of Mo, 0.5 to 1.1 percent of Si; 2.5 to 3.5 percent of Mn; 0.3 to 0.90 percent of Al; 0 < B < = 0.003%; the microstructure of the 1470MPa-grade steel plate is provided with retained austenite with the area ratio of 5-15%; in addition, the steel further contains at least one of martensite, tempered martensite and partition martensite, and the dislocation density of the martensite, the tempered martensite and the partition martensite is not lower than 0.55 * 10 < 15 > / m < 2 >. The invention further discloses a manufacturing method of the steel plate. The manufacturing method comprises the steps of smelting and continuous casting; hot rolling; pickling and cold rolling; and continuously annealing.

This invention discloses a method for preparing high-strength and high-surface-quality 6xxx aluminum alloy outer plates, relating to the field of aluminum alloy manufacturing technology. It solves the problem of balancing bake-hardening strength, mechanical properties, and surface roughness of existing 6xxx aluminum alloy outer plates. The method includes melting and casting, ingot homogenization heat treatment, flat ingot machining, preheating, hot-rolled temperature-controlled rolling, cold-rolled rolling, intermediate annealing, cold-rolled rolling, solution quenching, and pre-aging treatment steps. This invention controls the intermediate billet temperature of the rough-rolled plate by controlling the rolling speed of the hot rough rolling, optimizing the material microstructure and regulating the texture type and distribution density. This results in a fine and uniform grain structure and a low proportion of Goss and Cube textures in the 6xxx aluminum alloy outer plate material. This ensures that no roughness morphology appears on the surface after stamping and oilstone polishing, and also improves the bake-hardening performance of the material, giving it high bake-hardening strength.

The invention discloses a 6451 aluminum alloy plate based on dynamic diffusion field regulation and control, and belongs to the technical field of aluminum alloy digital manufacturing. Raw materials are melted and refined into a cast ingot according to set components, then the cast ingot is subjected to head cutting and face milling and then put into a heat treatment furnace to be subjected to homogenization treatment, the cast ingot subjected to homogenization treatment is cooled to the rolling starting temperature, heat preservation is conducted for a period of time, and then hot rolling is started. And after hot rolling is completed, the obtained hot-rolled plate is subjected to cold rolling and intermediate annealing, then cold rolling is conducted till the thickness of a final finished plate is achieved, the obtained cold-rolled plate is subjected to solid solution and water quenching treatment and then subjected to pre-aging treatment, a finished plate is obtained, the finished plate is subjected to paint baking treatment, and the final plate is obtained. By strictly controlling the preparation process, the high bake hardening performance of the plate is achieved on the premise that the low initial yield strength of the plate is guaranteed, and the plate is better suitable for automobile structural parts with high requirements for formability, strength and collision performance.

Disclosed in the present invention are an aluminum alloy sheet having high stability and high baking hardening performance, a preparation method therefor and a use thereof. The aluminum alloy sheet comprises the following components in percentage by mass: 0.20-1.50% of Si, less than or equal to 0.40% of Fe, 0.06-0.30% of Cu, 0.05-0.2% of Mn, 0.20-0.80% of Mg, less than or equal to 0.10% of Cr, 0.01-0.05% of Ti, and 0.005-0.045% of Sn, with the balance being Al. The composition of the aluminum alloy sheet and the preparation process according to the present invention are greatly different from those in the prior art. According to the sheet prepared in the present invention, vacancy, cluster, and precipitated phase states are effectively regulated, thereby greatly improving the stability of storage of the sheet at room temperature and the paint-baking hardenability of the sheet. The sheet also has low yield strength in a T4P state, high stability of storage at room temperature, and high paint-baking performance in a T8X state after baking, and can be widely used in industries such as automobiles.

The application provides a 260MPa-grade alloyed hot-dip galvanizing outer plate for new energy vehicles and a manufacturing method, and the chemical components and mass percentages are as follows: C: 0.0008%-0.0012%, Si: 0.01%-0.015%, Mn: 0.3%-0.5%, P: 0.02%-0.03%, Cu: 0.1%-0.4%, N: 0.003% or less, S: 0.003% or less, Al: 0.015%-0.02%, and the rest is Fe and inevitable impurities, and wherein the nano Cu precipitation size is between 5-10nm, the critical zone ferrite is 10%-14%, and the epitaxial ferrite is 85% or more. The manufacturing method comprises smelting, refining, casting, hot rolling, pickling, cold rolling, and alloyed hot-dip galvanizing. The application solves the natural aging problem of bake-hardening steel plates and ensures high strength.

The invention discloses a preparation method of Nb-Ti series cold-rolled bake-hardened steel with high formability and room temperature timeliness resistance, which is characterized by comprising the following steps: 1) converter production; 2) RH furnace production; 3) continuous casting production; 4) heating the casting blank; (5) finish rolling; (6) continuous annealing; the alloy comprises the following chemical components in percentage by weight: C is more than or equal to 0.0015% and less than or equal to 0.0030%; less than or equal to 0.030% of Si; 0.11% < = Mn < = 0.17%; 0.018% < = P < = 0.028%; s < = 0.0080%; 0.020% < = Alt < = 0.060%; ti is greater than or equal to 0.0025% and less than or equal to 0.0045 N is less than or equal to 0.0030%; and the balance of Fe and inevitable impurities. The invention aims to solve the problem that high BH value, excellent formability and room-temperature-resistant timeliness are difficult to consider at the same time in the prior art.