WO2021233247A1 - 一种深冲内胆用冷轧搪瓷钢及其制造方法 - Google Patents

一种深冲内胆用冷轧搪瓷钢及其制造方法 Download PDF

Info

Publication number
WO2021233247A1
WO2021233247A1 PCT/CN2021/094111 CN2021094111W WO2021233247A1 WO 2021233247 A1 WO2021233247 A1 WO 2021233247A1 CN 2021094111 W CN2021094111 W CN 2021094111W WO 2021233247 A1 WO2021233247 A1 WO 2021233247A1
Authority
WO
WIPO (PCT)
Prior art keywords
cold
steel
deep drawing
rolled
enamel steel
Prior art date
Application number
PCT/CN2021/094111
Other languages
English (en)
French (fr)
Inventor
魏娇
孙全社
王双成
陶孝勇
戴学诚
林长青
王俊凯
王金涛
王木
Original Assignee
宝山钢铁股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 宝山钢铁股份有限公司 filed Critical 宝山钢铁股份有限公司
Priority to JP2022570374A priority Critical patent/JP2023526409A/ja
Publication of WO2021233247A1 publication Critical patent/WO2021233247A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

Definitions

  • the invention relates to a metal material and a manufacturing method thereof, in particular to an enameled steel and a manufacturing method thereof.
  • the enamel liner is divided into two-stage and three-stage structures.
  • the main difference lies in the forming and welding process.
  • the two-section liner is formed by deep drawing and welding of two discs.
  • the entire liner has only one circular weld, while the three-section liner is welded by two end caps and a barrel body.
  • the end caps are stamped.
  • the process and the barrel body adopt the rolling process, and there are two circular welded seams and one straight seam on the whole inner liner.
  • two-stage enamel liners have developed rapidly.
  • deep drawing and thinning and deep drawing are used to form a higher degree of processing.
  • the punching depth is about 430mm when the diameter is 382mm, so .
  • the steel plate used for the two-stage enamel liner is required to have good formability.
  • the finished enamel liner has to withstand more than 20,000 high-pressure circulating water pressure tests, if the strength of the steel plate is insufficient after sintering, it will cause the liner to deform during the pressing process, resulting in peeling of the enamel. Therefore, it is required to be used for The steel plate of the two-stage enamel liner maintains high strength after enameling.
  • scale explosion has always been one of the main problems that plague the quality of enamel products.
  • the generation of scale explosion is related to the solubility of hydrogen atoms in steel.
  • the main source is hydrogen produced by the reaction of water vapor in the furnace and the crystal water of the enamel grinding additive with the steel plate during firing.
  • water chemically reacts with the iron and carbon atoms of the steel plate to generate hydrogen atoms, which enter the steel plate and exist near the dislocations, grain boundaries, vacancies, inclusions and precipitates of the steel plate.
  • the two-stage enamel liner must achieve good matching in terms of forming, pressure resistance, welding and enameling, and it is bound to require the steel plate used for the two-stage enamel liner to have good deep drawing performance and high enamel. After firing strength, good welding performance and excellent coating performance, especially excellent scale and explosion resistance.
  • the design features for cold-rolled deep-drawing enamel steel are based on ultra-low carbon, with a relatively high content of sulfur or nitrogen, and adding appropriate amounts of alloying elements, with titanium being the most common element.
  • titanium can fix free carbon, nitrogen, and sulfur atoms, reduce the solid solution of impurity elements, and improve the stamping performance of the steel plate;
  • titanium combines with carbon, nitrogen, and sulfur to form inclusions or second phases. They can be used as effective hydrogen storage traps to improve the hydrogen storage capacity of steel plates.
  • the two-section enamel liner steel used by the electric water heater manufacturers in China is mainly SPCC, and the composition characteristics are correct. Carbon, manganese and other elements are fine-tuned, and alloy elements such as titanium, niobium, and boron are not added. Therefore, there are certain problems in ensuring the quality of coating and welding.
  • One of the objectives of the present invention is to provide a cold-rolled enameled steel for deep-drawing inner tanks.
  • the cold-rolled enameled steel for deep-drawing inner tanks is based on low-carbon steel and added with appropriate amounts of boron, nitrogen, and trace titanium and niobium elements.
  • the auxiliary addition of copper, chromium and other alloying elements that can improve the adhesion performance of enamel can obtain uniform and fine ferrite + lamellar and degraded pearlite microstructure.
  • pearlite can play a role in strengthening the matrix, and the cementite particles in the pearlite act as irreversible hydrogen traps, which can improve the scale and explosion resistance of steel.
  • boron and nitrogen in the chemical composition design, adding appropriate amounts of boron and nitrogen to the steel, the two combine to form dispersed precipitated BN particles, which can not only serve as an effective hydrogen trap, significantly improve the anti-scale explosion performance of the steel, but also effectively improve the ferrite The ability to grow so that the steel obtains good formability.
  • Adding a trace amount of titanium to the steel can replace part of the boron element and combine with the nitrogen element to form TiN particles, which not only reduces the risk of corner cracks caused by BN to the continuous casting slab, but also benefits the welding performance.
  • the ferrite grain size of the cold-rolled enamel steel for deep drawing liner is 7.5-8 grade, the yield strength is 220-280MPa, the elongation is 38-43%, the hydrogen penetration time is ⁇ 8min, and it has passed through at least 850°C high temperature.
  • the yield strength after sintering for at least 12 minutes is ⁇ 200MPa. It has good formability, high strength after high-temperature enameling, excellent welding performance and excellent anti-scaling performance, and can be effectively applied to the production of enamel liners of electric water heaters with high forming requirements.
  • the present invention provides a cold-rolled enamel steel for deep-drawing liner, which contains the following chemical elements in the following mass percentages:
  • the mass percentage of each chemical element is:
  • C In the cold-rolled enamel steel for deep drawing liner of the present invention, C is the most basic strengthening element in steel, and carbon is mainly in the form of a small amount of lamellar and degraded pearlite in the steel of the present invention
  • the cementite particles in the pearlite act as a beneficial hydrogen storage trap, which supplements the improvement of the anti-scaling performance of the steel plate.
  • a small amount of lamellar and degraded pearlite is sintered at high temperature. A very small amount of CO and CO 2 gas is generated, which greatly reduces the bubbles or pinhole defects of the enamel layer, which is beneficial to improve the quality of the enamel layer.
  • the steel plate of the present invention is a steel for deep drawing liner for enamel liner, The mass percentage should not be too high. Therefore, the mass percentage of C in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.02-0.06%.
  • the mass percentage of C can be controlled between 0.02-0.04%.
  • Si In the cold-rolled enamel steel for deep drawing liner of the present invention, Si does not form carbides in the steel, but exists in the form of solid solution, which can play a role of solid solution strengthening, and at the same time, it is also a certain degree It can reduce the plasticity and toughness of steel. Si can also affect the adhesion properties of steel for enamel.
  • the SiO 2 film formed by the appropriate amount of Si during the high-temperature enameling process is conducive to the infiltration and penetration of the enamel into the steel. If the Si content is too high, it will hinder the chemistry between the enamel and the metal interface. reaction. In addition, excessive Si content is likely to cause scale defects in the product. Therefore, considering the formability, enamel adhesion performance, and anti-scaling performance, the mass percentage of Si in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be 0 ⁇ Si ⁇ 0.08%.
  • the mass percentage of Si can be controlled as 0 ⁇ Si ⁇ 0.05%. In some preferred embodiments, the mass percentage of Si can be controlled to 0.005-0.08%, preferably 0.005-0.05%.
  • Mn In the cold-rolled enamel steel for deep drawing liner of the present invention, the addition of Mn can play a role of solid solution strengthening in the steel. Mn plays the role of deoxidation and desulfurization during steelmaking, can eliminate FeO and FeS in steel, and the MnO and MnS produced at the same time can be used as effective "hydrogen traps" to reduce the scale explosion sensitivity to a certain extent.
  • the composite of MnO and MnS The precipitation will also improve the elongated shape of MnS into a spindle shape or an elliptical shape, avoiding the adverse effects of the simple precipitation of MnS on the transverse formability of the steel sheet.
  • the mass percentage of Mn in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.1-0.7%.
  • the mass percentage of Mn can be controlled between 0.2-0.5%.
  • P In the cold-rolled enamel steel for deep drawing liner of the present invention, P is an inevitable impurity element. Although it can increase the strength and hardness of the steel, it has serious segregation, increases temper brittleness, and reduces the plasticity and plasticity of steel. Toughness; in addition, it also has an adverse effect on welding performance. Its content should be strictly controlled. Therefore, the mass percentage of P in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be P ⁇ 0.055%.
  • the mass percentage of P can be controlled as P ⁇ 0.035%.
  • S In the cold-rolled enamel steel for deep drawing liner of the present invention, S is usually a harmful element in the steel.
  • the residual S element in the steel can inevitably form FeS with Fe, causing the hot brittleness of the steel to reduce The ductility and toughness of steel.
  • S is also detrimental to the welding performance of steel and will reduce the corrosion resistance of steel. Therefore, the mass percentage of S in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be S ⁇ 0.03%.
  • the mass percentage of S can be controlled to be S ⁇ 0.015%.
  • Al In the cold-rolled enamel steel for deep drawing liner of the present invention, Al is usually added as a deoxidizer for steelmaking in the steel. In addition, in order to avoid the aging caused by the solid solution of N atoms, Al is usually added to form AlN. On the one hand, it can refine the grains, and on the other hand, it can also serve as an effective "hydrogen trap". However, in the present invention, the nitride-forming element B is added, so Al mainly functions to deoxidize or adjust the oxygen content. The mass percentage of Al in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.01-0.07%.
  • the mass percentage of Al can be controlled between 0.01-0.04%.
  • B In the cold-rolled enamel steel for deep drawing liner of the present invention, B is a strong nitride forming element. In the present invention, B preferentially forms BN particles with N. On the one hand, there is a strong affinity between BN particles and hydrogen atoms. On the other hand, after cold rolling, a large number of vacancies around the BN particles can also effectively store hydrogen. Atoms, BN can strongly affect the diffusion and capacity of hydrogen atoms in steel, thereby significantly improving the anti-scaling performance of the steel plate. At the same time, the preferentially precipitated BN particles will inhibit the precipitation of fine AlN, thereby strengthening the growth ability of grains, increasing the ferrite grain size, and enabling the enamel steel to obtain better deep drawing properties.
  • the B element also has the effect of suppressing high-temperature deformation of the steel sheet, and can effectively prevent the cold-rolled enameled steel for deep drawing liner of the present invention from being deformed at high temperature during welding and enameling after forming. Therefore, comprehensively considering the anti-scaling performance, deep drawing performance and production stability, the mass percentage of B in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.002-0.009%, and the quality of N is controlled. The percentage is between 0.002-0.010%.
  • the mass percentage of B can be controlled between 0.0025-0.0065%, and the mass percentage of N can be controlled between 0.003-0.008%.
  • Ti is a strong carbon and nitride forming element. In low-carbon steel, Ti has a great influence on the strength of the steel plate.
  • the enameled steel of the present invention requires good formability, so micro-titanium treatment is performed.
  • Trace Ti can be combined with N to form dispersed TiN particles at high temperatures, which can consume a part of the N element, avoid the formation of excessive BN particles, and effectively reduce the risk of transverse cracks at the corners of the continuous casting slab.
  • the stable and dispersed TiN particles can control the austenite grain size in the welding heat-affected zone, thereby improving the welding performance of the steel.
  • the dispersed TiN particles can further improve the scale and explosion resistance of steel. Therefore, the mass percentage of Ti in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.002 and 0.015%.
  • the mass percentage of Ti can be controlled between 0.002-0.008%.
  • Nb In the cold-rolled enamel steel for deep drawing liner of the present invention, adding a trace amount of Nb can effectively improve the properties of the steel plate in the direction of 45°, so that the anisotropy of the steel plate is small. There are few defects in ear making, which is convenient to improve production efficiency and yield rate.
  • Nb exists in the form of solid solution Nb and NbC, which plays a role of solid solution dragging and precipitation pinning during the recrystallization process, thereby obtaining refined grains and effectively ensuring the strength of the steel plate after high-temperature enamelling. Therefore, the mass percentage of Nb in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.002 and 0.012%.
  • the mass percentage of Nb can be controlled between 0.002-0.006%.
  • an appropriate amount of Cr can adjust the unevenness of the steel plate surface during the production process, which is beneficial to improve the bonding strength between the steel plate substrate and the enamel glaze. If the Cr content in the steel is too low, it will not improve the adhesion of the enamel. If the Cr content in the steel is too high, it will not only increase the production cost, but also slow down the pickling process, which is not conducive to obtaining a rough surface. Therefore, the mass percentage of Cr in the cold-rolled enamel steel for deep drawing liner of the present invention is controlled to be between 0.01-0.08%.
  • the mass percentage of Cr can be controlled between 0.02-0.08%.
  • Cu, Ni and Mo In the cold-rolled enamel steel for deep drawing liner of the present invention, one or more of these elements Cu, Ni and Mo are inevitably present, and these elements have adhesion properties to enamel influential. In the high temperature enamel firing process, the appropriate amount of Cu, Ni and Mo content can promote the infiltration of the enamel to the metal, and promote the dissolution of iron and iron oxide in the enamel, forming a good transition layer that tightly combines the metal and the enamel layer. structure. In addition, nickel oxide is conducive to the formation of a more uniform bubble structure in the enamel layer and improves the quality of the enamel layer.
  • Cu+Ni+Mo is controlled to be less than or equal to 0.40%.
  • the mass percentages of Cu, Ni and Mo can be controlled to be Cu+Ni+Mo ⁇ 0.25%. In a further preferred embodiment, the mass percentage of Cu, Ni and Mo can be controlled to be Cu+Ni+Mo ⁇ 0.10%, more preferably ⁇ 0.05%.
  • the mass percentage of Cu is 0.005-0.02%. In some embodiments, the mass percentage of Ni is ⁇ 0.02%, preferably ⁇ 0.01%. In some embodiments, the mass percentage of Mo is ⁇ 0.02%, preferably ⁇ 0.01%. In some embodiments, the cold rolled enamel steel for deep drawing liner of the present invention contains: Cu, 0.005-0.02%; Ni, ⁇ 0.02%, preferably ⁇ 0.01%; and Mo, ⁇ 0.02%, preferably ⁇ 0.01%. Preferably, Cu+Ni+Mo ⁇ 0.05%.
  • B and N both represent the mass percentage of the corresponding element.
  • B is an element that is easy to burn and it is difficult to control stably.
  • B/N ratio is too high, that is, too much B element is added, which will form fine Fe23(CB) 6, thereby inhibiting the growth of grains and impairing the deep drawing performance of the steel sheet.
  • the B/N ratio is too low, the steel has poor scale and explosion resistance.
  • each chemical element also satisfies at least one of the following formulas:
  • B, Ti and N all represent the mass percentages of the corresponding elements.
  • the synergistic relationship between B, Ti and N in the cold rolled enamel steel for deep drawing liner of the present invention will affect the performance of the steel plate.
  • B and N do not satisfy 0.4 ⁇ B ⁇ N ⁇ 10 5 ⁇ 10
  • BN acts as an effective irreversible hydrogen trap in the steel, and a small amount of BN cannot improve the anti-scaling performance of the steel plate.
  • excessive BN particles will Precipitating at the austenite grain boundaries, these particles will be subjected to stress during the continuous casting process, and the concentration of stress will accelerate the formation and propagation of cracks, which will eventually lead to transverse cracks at the corners of the continuous casting slab, which will greatly increase the amount of trimming of the steel plate. Reduce the yield rate.
  • Ti and N do not satisfy -2 ⁇ Ti ⁇ (N-14/11B) ⁇ 10 5 ⁇ 12, too little Ti content will greatly increase the risk of continuous casting billet corner cracking caused by BN particles ;
  • Coarse TiN particles can't play a role in hindering the growth of crystal grains, which is detrimental to ensuring the welding performance and the strength after high-temperature enamelling.
  • the larger the TiN particles the smaller the effective surface area around them, that is, the fewer places for storing hydrogen atoms, which is not conducive to the improvement of scale and explosion resistance.
  • controlling the B element, Ti element and N element to satisfy the above-mentioned relationship is helpful to realize the proper amount, fineness and dispersion of BN and TiN particles in the steel.
  • the mass percentage of each chemical element satisfies at least one of the following items:
  • the cold-rolled enamel steel for deep-drawing liner of the present invention its microstructure is uniform and fine ferrite, lamellar pearlite and degraded pearlite, wherein the ratio of pearlite is ( Volume ratio) ⁇ 3%; wherein there are a large number of vacancies between cementite particles and ferrite in the pearlite (including lamellar pearlite and degraded pearlite).
  • the vacancies are generated during the cold rolling process and are determined by the number and size of the second phase particles and the size of the cold rolling reduction rate. The more second phase particles, the smaller and the smaller the cold rolling reduction rate, the resulting vacancies more.
  • the lamellar pearlite is located at the ferrite trigeminal grain boundary, and the cementite particles in the degraded pearlite are located at the ferrite Grain boundaries and inside the grains.
  • the ferrite grain size is 7.5-8 grade.
  • the cold-rolled enamel steel for deep drawing liner of the present invention its performance satisfies at least one of the following items: the yield strength is 220-280MPa, the elongation is 38-43%, and the hydrogen penetration The penetration time is ⁇ 8min, and the yield strength after at least 850°C high temperature enamelling is at least 12min is ⁇ 200MPa. In some embodiments, the tensile strength of the cold-rolled enamel steel for deep drawing liner of the present invention is 320-390 MPa.
  • another object of the present invention is to provide a method for manufacturing cold-rolled enamel steel for deep-drawing inner tanks.
  • the manufacturing method adopts a suitable controlled rolling and controlled cooling process and a high-temperature rapid continuous annealing process, which can achieve boron in steel.
  • Titanium and niobium carbonitrides dispersed distribution, so as to obtain uniform and fine ferrite + a small amount of lamellar and degraded pearlite structure, the ferrite of cold-rolled enameled steel for deep drawing liner produced by this manufacturing method
  • the bulk grain size is 7.5-8
  • the yield strength is 220-280MPa
  • the elongation is 38-43%
  • the hydrogen penetration time is ⁇ 8min
  • the yield strength after at least 850°C high temperature enamelling for at least 12min is ⁇ 200MPa, which is good Its formability, high strength after high-temperature enameling, excellent welding performance and excellent anti-scaling performance can be effectively applied to the production of enamel liners of electric water heaters with high forming requirements.
  • the present invention proposes the above-mentioned manufacturing method of cold-rolled enamel steel for deep-drawing liner, which includes the following steps:
  • soaking temperature is 800-830°C, soaking time is 100-150s, over-aging temperature is between 350-450°C, over-aging time is 250-350s;
  • the smelting and refining operations in step (1) can remove harmful gases such as nitrogen and hydrogen in molten steel to achieve decarburization and deoxidation, and The composition and temperature of molten steel can be evened according to the final goal.
  • the molten steel in the continuous casting operation of step (1), can be transported to the turntable and passed through the tundish, crystallizer, secondary cooling section, tension leveler and other equipment to obtain a continuous casting with good shape, surface quality and internal structure. Casting billet.
  • pickling in the step (4), can effectively remove the oxide scale on the surface of the hot-rolled steel strip to facilitate subsequent operations.
  • the cold rolling reduction rate will affect the formability and scale resistance of the steel.
  • the greater the reduction rate the greater the deformation storage energy of the steel sheet, and the easier it is to recrystallize during annealing, which is conducive to the full development of the recrystallization texture.
  • the second phase particles are crushed during the cold rolling process, thereby forming vacancies between the surrounding and the ferrite matrix, which helps to hinder the diffusion of hydrogen atoms.
  • the greater the cold rolling reduction rate the more vacancies and the resistance to scale The stronger the explosive performance.
  • the cold rolling reduction rate is controlled to be 60-70%.
  • the thickness of the cold rolled sheet may be in the range of 1.5-2.5 mm, such as 1.5-2.0 mm.
  • a high temperature and rapid continuous annealing process is adopted, the soaking temperature is controlled to be 800-830°C, the soaking time is controlled to be 100-150s, and the over-aging temperature is controlled to be between 350-450°C. , The control over-aging time is 250-350s. It can cooperate with the cold rolling process to realize the formation and development of the recrystallization texture, so as to obtain uniform and fine ferrite grains, promote the strength and plasticity of the steel plate at the same time, and at the same time, the cementite particles can also be regenerated during the annealing process. Dissolution and precipitation help the steel plate to exert its anti-scaling performance.
  • the heating temperature is 1100-1250°C.
  • the heating temperature is 1100-1250°C to obtain a uniform austenite structure. If the heating temperature is lower than 1100°C, the deformation resistance of the steel is large, and hot rolling is difficult to perform. Correspondingly, if the heating temperature is higher than 1250°C, the billet is prone to problems such as decarburization and thick oxide scale during the heating process.
  • the heating time of step (2) can be controlled at 120-200 minutes, such as 130-180 minutes.
  • step (3) the final rolling temperature of the hot rolling is controlled to be 880-920°C, and the coiling temperature is controlled to be 680-720°C.
  • the final rolling temperature of the hot rolling is controlled to be 880-920°C. This is because: if the final rolling temperature is lower than 880°C, the final rolling enters the two-phase zone, resulting in a fine ferrite mixed structure transformed by massive pre-eutectoid ferrite and deformed austenite, which will adversely affect the mechanical properties of the steel sheet. Impact. If the finishing temperature is higher than 920°C, the deformed austenite is likely to recover, which is not conducive to the refinement of ferrite grains.
  • a higher coiling temperature is adopted, and the coiling temperature is controlled between 680-720°C, which not only helps to improve the formability of the steel sheet, but also facilitates the full dispersion and precipitation of the second phase particles, which can effectively improve Anti-scale explosion performance of steel.
  • step (7) the leveling reduction rate is controlled to be 0.8-1.2%.
  • step (7) after the leveling reduction rate is controlled to 0.8-1.2% for leveling, not only can the flatness and surface finish of the steel plate be improved, but the steel plate can be stamped after being stored for a period of time. A "yielding platform" appears.
  • the cold-rolled enamel steel for deep drawing liner and the manufacturing method thereof of the present invention have the following advantages and beneficial effects:
  • the cold-rolled enamel steel for deep drawing liner of the present invention is based on low-carbon steel, added with appropriate amounts of boron, nitrogen and trace elements of titanium and niobium, and auxiliary addition of copper, chromium and other alloy elements that improve the adhesion performance of enamel , To obtain uniform fine ferrite + lamellar and degraded pearlite microstructure.
  • pearlite can play a role in strengthening the matrix, and the cementite particles in the pearlite act as irreversible hydrogen traps, which can improve the scale and explosion resistance of steel.
  • boron and nitrogen in the chemical composition design, adding appropriate amounts of boron and nitrogen to the steel, the two combine to form dispersed precipitated BN particles, which can not only serve as an effective hydrogen trap, significantly improve the anti-scale explosion performance of the steel, but also effectively improve the ferrite The ability to grow so that the steel obtains good formability.
  • Adding a trace amount of titanium to the steel can replace part of the boron element and combine with the nitrogen element to form TiN particles, which not only reduces the risk of corner cracks caused by BN to the continuous casting slab, but also benefits the welding performance.
  • the ferrite grain size of the cold-rolled enamel steel for deep drawing liner is 7.5-8 grade, the yield strength is 220-280MPa, the elongation is 38-43%, the hydrogen penetration time is ⁇ 8min, and it has passed through at least 850°C high temperature.
  • the yield strength after sintering for at least 12 minutes is ⁇ 200MPa. It has good formability, high strength after high-temperature enameling, excellent welding performance and excellent anti-scaling performance, and can be effectively applied to the production of enamel liners of electric water heaters with high forming requirements.
  • the manufacturing method of the present invention adopts a suitable controlled rolling and cooling process and a high-temperature rapid continuous annealing process to realize the dispersion distribution of carbonitrides of boron, titanium and niobium, so that the manufacturing method of the present invention obtains
  • the cold-rolled enamel steel for deep-drawing liner obtains uniform and fine ferrite + a small amount of lamellar and degraded pearlite structure.
  • lamellar pearlite is located at the ferrite trigeminal grain boundary, and the degraded pearlite is The cementite particles are located in the ferrite grain boundaries and inside the grains, which effectively guarantees that the cold-rolled enamel steel for deep-drawing liners has high strength after high-temperature enameling, high formability and excellent anti-scaling, etc. characteristic.
  • Fig. 1 is a microstructure diagram of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Figure 2 shows the typical pearlite morphology in the microstructure of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Fig. 3 shows the morphology of the degraded pearlite group in the microstructure of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Figure 4 shows the location of boron in the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Table 1 lists the mass percentages of various chemical elements in the cold-rolled enamel steel for deep-drawing liners of Examples 1-6 and the enamel steel of Comparative Example 1-2.
  • the cold-rolled enamel steel for deep-drawing liners of Examples 1-6 of the present invention and the enamel steel of Comparative Example 1-2 were prepared by the following steps:
  • Hot rolling and coiling control the final rolling temperature of hot rolling to 880-920°C, after rolling, perform water cooling, air cooling or slow cooling, and then carry out coiling, and control the coiling temperature to 680-720°C;
  • soaking temperature is 800-830°C, soaking time is 100-150s, over-aging temperature is between 350-450°C, and over-aging time is 250-350s;
  • Table 2-1 and Table 2-2 list the specific process parameters of the cold-rolled enamel steel for deep drawing liner of Example 1-6 and the enamel steel of Comparative Example 1-2.
  • the over-aging temperature changes during the actual operation, not stable at a fixed value, but during the over-aging time period, the temperature gradually decreases, so in step (6) of Table 2-2
  • the over-aging temperature is presented as a range value rather than a point value in each example and comparative example.
  • the cold-rolled enamel steel for deep drawing liner of Examples 1-6 and the enamel steel of Comparative Example 1-2 were subjected to various performance tests.
  • the specific test methods are as follows:
  • the cold-rolled enamel steels of Examples 1-6 and Comparative Examples 1-2 were subjected to a high-temperature simulated enamel enamel test.
  • the enamel temperature was 850° C., and the furnace time was 12 minutes.
  • the measured mechanical properties are shown in Table 3.
  • the cold-rolled steel for enamel enamel of Examples 1-6 and Comparative Example 1-2 adopts wet enamel coating process. Drying in a drying furnace at °C, and finally firing in a high-temperature furnace. The enameling temperature is 850°C, and the furnace time is 12 minutes. After the enameled steel plate is air-cooled to room temperature, the adhesion performance is tested according to European standard EN 10209-2013 , The steel ball falls from a height of 750mm to impact the surface of the steel plate after enamelling, and the adhesion level is judged by observing the degree of bonding between the enamel and the steel plate, and the steel plate after the enamelling is placed for more than 72 hours to observe the scale explosion.
  • the hydrogen penetration value of the steel plate was tested in accordance with the European standard EN 10209-2013, which was converted into the hydrogen penetration time of 1mm thickness.
  • the yield strength and tensile strength are tested in accordance with GB/T 228.1-2010, and the elongation is tested in accordance with GB/T 228.1-2010.
  • Table 3 lists the performance test results of the cold-rolled enamel steel for deep-drawing liners of Examples 1-6 and the enamel steel of Comparative Example 1-2.
  • A1 represents the best adhesion performance
  • A4 represents the worst adhesion performance
  • the phase ratio of pearlite in the cold-rolled enamel steel for deep drawing liner of Examples 1-6 of the present invention is all less than 3%, and the ferrite grain size is all 7.5-8 grades.
  • the yield strength is between 220-280MPa, the elongation is between 38.0-43.0%, and the yield strength after at least 850°C high temperature enamelling for at least 12 minutes is ⁇ 200MPa.
  • the degree of bonding between the enamel layer and the steel plate is good, which is A1 level, and there is no scale explosion phenomenon after being placed for a long time.
  • the hydrogen penetration value of the steel plate (converted to 1mm thickness) is ⁇ 8min, which exceeds the threshold value of 6.7min specified in the European standard EN 10209-2013. It can be seen that the deep drawing liner of each embodiment of the present invention is used for cold rolling Enamel steel will not explode even when coated on both sides, and has excellent anti-scale and explosion properties.
  • Fig. 1 is a microstructure diagram of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Figure 2 shows the typical pearlite morphology in the microstructure of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Fig. 3 shows the morphology of the degraded pearlite group in the microstructure of the cold-rolled enamel steel for deep drawing liner of Example 1.
  • Figure 4 shows the location of boron in the cold-rolled enamel steel for deep drawing liner of Example 1.
  • the B element in the steel does not exist in the form of elemental atoms, but combines with the N element or the C element to form a complex compound BN or boron carbide particles, segregating At the grain boundary or on the cementite within the grain.

Abstract

本发明公开了一种深冲内胆用冷轧搪瓷钢及其制造方法，其含有质量百分比如下的下述化学元素：C：0.02-0.06％，0＜Si≤0.08％，Mn：0.1-0.7％，P≤0.055％，S≤0.03％，Al：0.01-0.07％，N：0.002-0.010％，B：0.002-0.009％，Ti：0.002-0.015％，Nb：0.002-0.012％，Cr：0.01-0.08％，以及Cu、Ni和Mo的至少其中一种，其中Cu+Ni+Mo≤0.40％。本发明所述的深冲内胆用冷轧搪瓷钢采用合理的化学成分和工艺设计，具有良好的成形性、较高的高温搪烧后强度、优异的焊接性能和优良的抗鳞爆性能。

Description

一种深冲内胆用冷轧搪瓷钢及其制造方法 技术领域
本发明涉及一种金属材料及其制造方法，尤其涉及一种搪瓷钢及其制造方法。
背景技术
搪瓷内胆分为二段式和三段式两种结构，其主要区别在于成形和焊接过程。二段式内胆由两个圆片经过深冲后焊接而成，整个内胆只有一条环形焊缝，而三段式内胆由两个端盖和一个桶身焊接而成，端盖采用冲压工艺、桶身采用卷圆工艺，整个内胆上有两条环形焊缝和一条直缝。
近年来，随着工业生产从提高产品质量和降低综合成本的方面考虑，二段式搪瓷内胆得到了快速发展。二段式内胆在成形的过程中，通过深冲加工、减薄拉深加工进行加工程度较高的成型，如对80L典型的内胆来说，直径为382mm时其冲压深度达430mm左右，因此，要求用于二段式搪瓷内胆的钢板具有较好的成形性。另外，由于成品的搪瓷内胆要经受2万次以上高压循环水打压试验，若钢板烧结后的强度不足，则会引起内胆在打压过程中发生变形，从而导致搪瓷剥落，因此，要求用于二段式搪瓷内胆的钢板在搪烧后保持较高的强度。
此外，鳞爆缺陷一直是困扰搪瓷制品质量的最主要问题之一，鳞爆的产生跟氢原子在钢中的溶解度有关。氢的来源有三种：基体钢板中溶解的氢、酸洗和烧成过程产生的氢，最主要来源是烧成时炉内水汽、瓷釉磨加物的结晶水与钢板反应生产的氢。高温烧结过程中水与钢板的铁、碳原子发生化学反应生成氢原子，进入到钢板中，存在于钢板的位错、晶界、空位、夹杂物和析出物等结构附近，随着钢板冷却，氢原子在钢中的溶解度下降，聚集在钢板与搪瓷层界面处，当氢气的压力超过搪瓷层的抗张强度时，冲破瓷层，造成所谓的鳞爆缺陷。在某热水器制造商的极端生产条件下，立式机型在搪烧过程中开口端均向下，不利于水蒸气挥发，因此，要求钢板本身有足够的吸氢场所，来满足较高的抗鳞爆要求。
由此可见，二段式搪瓷内胆要实现成形、耐压、焊接和涂搪等方面的良好匹配，势必要求用于二段式搪瓷内胆的钢板具有良好的深冲性能、较高的搪烧后强度、良 好的焊接性能和优良的涂搪性能，尤其是优良的抗鳞爆性能。
现有技术中，针对冷轧深冲搪瓷用钢的设计特点均是以超低碳为基础，硫或氮的含量较高，加入适量的合金元素，以钛元素最为常见。一方面，钛元素可以固定自由的碳、氮、硫原子，降低杂质元素的固溶量，提高钢板的冲压性能；另一方面，钛与碳、氮、硫结合成夹杂物或者第二相，它们可以作为有效的贮氢陷阱，提高钢板的贮氢能力。然而，需要说明的是这样的设计虽然可以同时提高钢板的深冲性能和抗鳞爆性能，但是基板的屈服强度偏低，经过高温烧结后屈服强度会进一步下降，无法满足搪瓷内胆的承压要求，而且在设计中添加了大量的合金元素，制造成本较高。
目前，国内很少有针对性地对二段式搪瓷内胆专用钢板进行开发，我国电热水器生产厂家所使用的二段式搪瓷内胆用钢主要以普冷钢SPCC为主，成分特点是对碳、锰等元素进行微调，不加入钛、铌和硼等合金元素，因此在保证涂搪质量和焊接质量方面均存在一定问题。
发明内容
本发明的目的之一在于提供一种深冲内胆用冷轧搪瓷钢，该深冲内胆用冷轧搪瓷钢以低碳钢为基础，添加适量的硼、氮元素和微量钛、铌元素，辅助添加铜、铬等对搪瓷密着性能有提升的合金元素，可以获得均匀细小的铁素体+片层状和退化的珠光体的微观组织。其中，珠光体可以起到强化基体的作用，同时珠光体中的渗碳体颗粒作为不可逆氢陷阱，可以提高钢的抗鳞爆性能。在化学成分设计中，向钢中添加适量的硼和氮，二者结合生成弥散析出的BN颗粒，不仅可以作为有效的氢陷阱，显著提高钢的抗鳞爆性能，还可以有效提高铁素体生长的能力，以使钢获得良好的成形性。钢中添加微量钛能代替部分硼元素，与氮元素结合成TiN粒子，既降低BN给连铸坯带来的角裂风险，又有利于焊接性能。
该深冲内胆用冷轧搪瓷钢的铁素体晶粒度为7.5-8级，屈服强度为220-280MPa，延伸率为38-43％，氢穿透时间≥8min，经过至少850℃高温搪烧至少12min后的屈服强度≥200MPa。其具有良好的成形性、较高的高温搪烧后强度、优异的焊接性能和优良的抗鳞爆性能，可以有效适用于制作成形要求较高的电热水器搪瓷内胆等。
为了实现上述目的，本发明提供了一种深冲内胆用冷轧搪瓷钢，其含有质量百分比如下的下述化学元素：
C：0.02-0.06％，0＜Si≤0.08％，Mn：0.1-0.7％，P≤0.055％，S≤0.03％，Al：0.01-0.07％，N：0.002-0.010％，B：0.002-0.009％，Ti：0.002-0.015％，Nb：0.002-0.012％，Cr：0.01-0.08％，以及Cu、Ni和Mo中的至少一种，其中Cu+Ni+Mo≤0.40％。上式中Cu、Ni和Mo均表示相应元素的质量百分含量。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其各化学元素质量百分比为：
C：0.02-0.06％，0＜Si≤0.08％，Mn：0.1-0.7％，P≤0.055％，S≤0.03％，Al：0.01-0.07％，N：0.002-0.010％，B：0.002-0.009％，Ti：0.002-0.015％，Nb：0.002-0.012％，Cr：0.01-0.08％，以及Cu、Ni和Mo中的至少一种，其中Cu+Ni+Mo≤0.40％，余量为Fe及其他不可避免的杂质。
在本发明所述的深冲内胆用冷轧搪瓷钢中，各化学元素的设计原理如下所述：
C：在本发明所述的深冲内胆用冷轧搪瓷钢中，C在钢中是最基本的强化元素，碳在本发明的钢中主要以少量片层状和退化的珠光体的形式存在，一方面珠光体中的渗碳体颗粒作为有益的贮氢陷阱，对提高钢板的抗鳞爆性能起到补充作用，另一方面，少量片层状和退化的珠光体在高温搪烧时产生极少量的CO、CO 2气体，使得搪瓷层的气泡或者针孔缺陷大大降低，有利于提高瓷层质量。但需要注意的是，随着钢中C百分含量的上升，钢的强度提高，塑性和韧性相应下降，本发明的钢板是一种用于搪瓷内胆的深冲内胆用钢，C的质量百分比不宜过高。因此在本发明所述的深冲内胆用冷轧搪瓷钢中控制C的质量百分比在0.02-0.06％之间。
在一些优选的实施方式中，C的质量百分比可以控制在0.02-0.04％之间。
Si：在本发明所述的深冲内胆用冷轧搪瓷钢中，Si在钢中不形成碳化物，而是以固溶体的形式存在，可以起到固溶强化的作用，同时也在一定程度上可以降低钢的塑性和韧性。Si还可以影响搪瓷用钢的密着性能，适量的Si在高温搪烧过程中形成的SiO 2薄膜有利于瓷釉对钢的浸润与渗透，若Si含量过高则阻碍瓷釉与金属界面之间的化学反应。另外，过高的Si含量容易导致制品出现鳞爆缺陷。因此，考虑到成形性能、搪瓷密着性能和抗鳞爆性能，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Si的质量百分比为0＜Si≤0.08％。
在一些优选的实施方式中，Si的质量百分比可以控制为0＜Si≤0.05％。在一些优选的实施方式中，Si的质量百分比可以控制为0.005-0.08％，优选为0.005-0.05％。
Mn：在本发明所述的深冲内胆用冷轧搪瓷钢中，添加Mn可以在钢中起到固溶 强化的作用。Mn在炼钢时起到脱氧和脱硫的作用，可以消除钢中FeO和FeS，同时产生的MnO和MnS可作为有效“氢陷阱”，在一定程度上降低鳞爆敏感性，MnO与MnS的复合析出，还会将MnS的长条状改善为纺锤状或者椭圆形，避免单纯析出MnS对钢板横向成形性带来的不良影响。但需要注意的是，钢中Mn含量超过0.7％时，会降低钢的塑性、焊接性能和搪瓷密着性能。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Mn的质量百分比在0.1-0.7％之间。
在一些优选的实施方式中，Mn的质量百分比可以控制在0.2-0.5％之间。
P：在本发明所述的深冲内胆用冷轧搪瓷钢中，P是不可避免的杂质元素，虽能提高钢的强度和硬度，但偏析严重，增加回火脆性，降低钢的塑性和韧性；此外，对焊接性能也有不利影响。应严格控制其含量，因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制P的质量百分比为P≤0.055％。
在一些优选的实施方式中，P的质量百分比可以控制为P≤0.035％。
S：在本发明所述的深冲内胆用冷轧搪瓷钢中，S在钢中通常是有害元素，钢中残余的S元素不可避免可以与Fe形成FeS，引发钢的热脆性，从而降低钢的延展性和韧性。此外，S对钢的焊接性能也不利，会降低钢的耐腐蚀性。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制S的质量百分比为S≤0.03％。
在一些优选的实施方式中，S的质量百分比可以控制为S≤0.015％。
Al：在本发明所述的深冲内胆用冷轧搪瓷钢中，Al在钢中通常作为炼钢的脱氧剂而加入。此外，为了避免固溶的N原子引起时效，通常也会加入Al从而形成AlN，一方面能细化晶粒，另一方面也可作为有效“氢陷阱”。但是在本发明中，添加了氮化物形成元素B，因此Al主要起到脱氧或者调整氧含量的作用。在本发明所述的深冲内胆用冷轧搪瓷钢中控制Al的质量百分比在0.01-0.07％之间。
在一些优选的实施方式中，Al的质量百分比可以控制在0.01-0.04％之间。
B和N：在本发明所述的深冲内胆用冷轧搪瓷钢中，B是强氮化物形成元素。在本发明中，B优先与N形成BN粒子，一方面，BN颗粒与氢原子之间有强烈的亲和作用，另一方面，经过冷轧以后，BN颗粒周围产生大量空位也可以有效贮存氢原子，BN可以强烈影响氢原子在钢中的扩散和容量，从而显著提高钢板的抗鳞爆性能。同时，优先析出的BN颗粒会抑制细小AlN的析出，从而加强晶粒的生长能力，增大铁素体晶粒尺寸，使搪瓷钢获得较好的深冲性能。另外，需要说明的是，B元素还具有抑制钢板高温变形的作用，可有效防止本发明所述的深冲内胆用冷轧搪瓷钢在 成形之后的焊接和涂搪过程中发生高温变形。因此，综合考虑抗鳞爆性能、深冲性能和生产稳定性，在本发明所述的深冲内胆用冷轧搪瓷钢中控制B的质量百分比在0.002-0.009％之间，控制N的质量百分比在0.002-0.010％之间。
在一些优选的实施方式中，B的质量百分比可以控制在0.0025-0.0065％之间，N的质量百分比可以控制在0.003-0.008％之间。
Ti：在本发明所述的深冲内胆用冷轧搪瓷钢中，Ti是强碳、氮化物形成元素。在低碳钢中，Ti对钢板强度的影响非常大，本发明所述的搪瓷钢要求具有良好的成形性，因此进行微钛处理。微量Ti在高温可以与N结合成弥散的TiN颗粒，能消耗一部分N元素，避免形成过多的BN颗粒，可有效降低连铸坯出现角部横裂纹的风险。同时，稳定、弥散的TiN颗粒能够控制焊接热影响区的奥氏体晶粒尺寸，从而改善钢的焊接性能。此外，需要说明的是，弥散析出的TiN颗粒还能进一步提高钢的抗鳞爆性能。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Ti的质量百分比在0.002-0.015％之间。
在一些优选的实施方式中，Ti的质量百分比可以控制在0.002-0.008％之间。
Nb：在本发明所述的深冲内胆用冷轧搪瓷钢中，添加微量Nb元素可以有效改善钢板45°方向的性能，使得钢板的各向异性较小，钢板在深拉伸成型后的制耳缺陷少，便于提高生产效率和成材率。此外，Nb以固溶Nb和NbC的形式存在，对再结晶过程起到固溶拖拽和析出钉扎的作用，从而得到细化的晶粒，有效保证钢板高温搪烧后的强度。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Nb的质量百分比在0.002-0.012％之间。
在一些优选的实施方式中，Nb的质量百分比可以控制在0.002-0.006％之间。
Cr：在本发明所述的深冲内胆用冷轧搪瓷钢中，适量的Cr元素在生产过程中可以调整钢板表面的凹凸状态，有利于提高钢板基体与搪瓷釉之间的结合强度。若钢中Cr含量偏低，则起不到提高搪瓷密着性的作用，而若钢中Cr含量偏高，不仅会造成生产成本增加，还会减缓酸洗过程的进行，不利于获得粗糙表面。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Cr的质量百分比在0.01-0.08％之间。
在一些优选的实施方式中，Cr的质量百分比可以控制在0.02-0.08％之间。
Cu、Ni和Mo：在本发明所述的深冲内胆用冷轧搪瓷钢中，不可避免地存在Cu、Ni和Mo这些元素中的一种或者二种以上，这些元素均对搪瓷密着性能有影响。在高温搪烧过程中，适量的Cu、Ni和Mo含量可以促进瓷釉对金属的浸润，且促进铁 与氧化铁在瓷釉中的溶解，形成使金属和搪瓷层紧密结合在一起的良好的过渡层结构。另外，镍的氧化物有利于搪瓷层形成较为均匀的气泡结构，提高搪瓷层质量。然而，需要注意的是，若Cu、Ni和Mo这些元素的含量过高，不仅会增加合金成本，还会减弱金属与瓷釉之间的结合力。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中控制Cu+Ni+Mo≤0.40％。
在一些优选的实施方式中，Cu、Ni和Mo质量百分比可以控制为Cu+Ni+Mo≤0.25％。在进一步优选的实施方式中，Cu、Ni和Mo质量百分比可以控制为Cu+Ni+Mo≤0.10％，更优选≤0.05％。
在一些实施方案中，Cu的质量百分比为0.005-0.02％。在一些实施方案中，Ni的质量百分比为≤0.02％，优选≤0.01％。在一些实施方案中，Mo的质量百分比为≤0.02％，优选≤0.01％。在一些实施方案中，本发明的深冲内胆用冷轧搪瓷钢含有：Cu，0.005-0.02％；Ni，≤0.02％，优选≤0.01％；和Mo，≤0.02％，优选≤0.01％。优选地，Cu+Ni+Mo≤0.05％。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其中B和N的质量百分比含量满足：B/N＝0.8-1.5。式中B和N均表示相应元素的质量百分含量。
在上述技术方案中，本发明所述的深冲内胆用冷轧搪瓷钢中，在控制单一元素含量的同时，控制B和N的质量百分比含量满足：B/N＝0.8-1.5是因为：在炼钢过程中B属于易烧损元素，很难稳定控制，B含量越高越难控制，当B/N比例过高时，即加入的B元素过多，会形成细小的Fe23(CB)6，从而抑制晶粒生长，损害钢板的深冲性能。而当B/N的比例过低时，钢的抗鳞爆性能差。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，各化学元素还满足下列各式的至少其中之一：
0.4≤B×N×10 5≤10：
-2≤Ti×(N-14/11B)×10 5≤12；
式中B、Ti和N均表示相应元素的质量百分含量。
在本发明所述的技术方案中，本发明所述的深冲内胆用冷轧搪瓷钢中的B、Ti和N之间的协同关系会影响钢板的性能。当B和N不满足0.4≤B×N×10 5≤10时，BN在钢中作为有效的不可逆氢陷阱，少量的BN则无法提升钢板的抗鳞爆性能，相应地，过量的BN颗粒会在奥氏体晶界析出，这些粒子在连铸过程中会受到应力作用，应力集中则加速裂纹的形成和扩展，最终导致连铸坯角部横向裂纹，这会大大 增加钢板的切边量，降低成材率。
若B、Ti和N之间不满足-2≤Ti×(N-14/11B)×10 5≤12时，Ti的含量太少则会大大增加BN颗粒造成的连铸坯角裂问题的风险；Ti和N的固溶度积越大，越容易在钢液中形成粗大的TiN颗粒。粗大的TiN颗粒无法起到阻碍晶粒长大的作用，对保证焊接性能和高温搪烧后的强度均不利。TiN颗粒越大，其周围有效表面积越小，即用于贮存氢原子的场所越少，不利于抗鳞爆性能的提升。因此，在本发明所述的深冲内胆用冷轧搪瓷钢中，控制B元素、Ti元素和N元素满足上述关系，有助于实现BN和TiN颗粒在钢中适量、细小、弥散分布。优选地，-2≤Ti×(N-14/11B)×10 5≤0。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其各化学元素质量百分含量满足下述各项的至少其中之一：
C：0.02-0.04％，0＜Si≤0.05％，Mn：0.2-0.5％，P≤0.035％，S≤0.015％，Al：0.01-0.04％，N：0.003-0.008％，B：0.0025-0.0065％，Ti：0.002-0.008％，Nb：0.002-0.006％，Cr：0.02-0.08％，以及Cu、Ni和Mo的至少其中一种，其中Cu+Ni+Mo≤0.25％；优选地，Cu，0.005-0.02％；Ni，≤0.02％，优选≤0.01％；和Mo，≤0.02％，优选≤0.01％，且优选地，Cu+Ni+Mo≤0.05％。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其微观组织为均匀细小的铁素体、片层状的珠光体以及退化的珠光体，其中珠光体的相比例(体积比)＜3％；其中所述珠光体(包括片层状珠光体和退化的珠光体)中的渗碳体颗粒与铁素体之间存在大量空位。所述空位在冷轧过程中产生，由第二相粒子的数量、尺寸以及冷轧压下率的大小决定，第二相粒子越多、越细小，冷轧压下率越大，产生的空位越多。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其中片层状的珠光体位于铁素体三叉晶界处，退化的珠光体中的渗碳体颗粒位于铁素体晶界和晶粒内部。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其中铁素体晶粒度为7.5-8级。
进一步地，在本发明所述的深冲内胆用冷轧搪瓷钢中，其性能满足下述各项的至少其中之一：屈服强度为220-280MPa，延伸率为38-43％，氢穿透时间≥8min，经过至少850℃高温搪烧至少12min后的屈服强度≥200MPa。在一些实施方式中，本发明所述的深冲内胆用冷轧搪瓷钢的抗拉强度为320-390MPa。
相应地，本发明的另一目的在于提供一种深冲内胆用冷轧搪瓷钢的制造方法，该制造方法采用了合适的控轧控冷工艺和高温快速连续退火工艺，可以实现钢中硼、钛和铌碳氮化物的弥散分布，从而得到均匀细小的铁素体+少量片层状和退化的珠光体组织，采用该制造方法制得的深冲内胆用冷轧搪瓷钢的铁素体晶粒度为7.5-8级，屈服强度为220-280MPa，延伸率为38-43％，氢穿透时间≥8min，经过至少850℃高温搪烧至少12min后的屈服强度≥200MPa，具有良好的成形性、较高的高温搪烧后强度、优异的焊接性能和优良的抗鳞爆性能，可以有效适用于制作成形要求较高的电热水器搪瓷内胆等。
为了实现上述目的，本发明提出了上述的深冲内胆用冷轧搪瓷钢的制造方法，包括步骤：
(1)冶炼、精炼和连铸；
(2)板坯加热；
(3)热轧和卷取；
(4)酸洗；
(5)冷轧：控制冷轧压下率为60-70％；
(6)连续退火：均热温度为800-830℃，均热时间为100-150s，过时效温度为350-450℃之间，过时效时间为250-350s；
(7)平整。
在本发明所述的深冲内胆用冷轧搪瓷钢的制造方法中，步骤(1)中的冶炼和精炼操作可以去除钢液中的氮气、氢气等有害气体，实现脱碳和脱氧，并可以根据最终目标均匀钢水的成分和温度。此外，在步骤(1)的连铸操作中，钢水可以运至回转台，经过中间包、结晶器、二次冷却段、拉矫机等设备，从而获得形状、表面质量和内部结构良好的连铸坯。
在本发明所述的制造方法中，在所述步骤(4)中，酸洗可以有效去除热轧带钢表面的氧化铁皮，以方便后续操作。
在步骤(5)的冷轧操作中，冷轧压下率会影响钢的成形性和抗鳞爆性能。一般来讲，压下率越大，钢板的形变储存能越大，退火时越容易发生再结晶，有利于再结晶织构的充分发展。第二相颗粒在冷轧过程中被碾碎，从而在其周围与铁素体基体之间形成空位，有助于阻碍氢原子的扩散，冷轧压下率越大，空位越多，抗鳞爆性能越强。当冷轧压下率低于60％时，难以获得较好的成形性能，而若冷轧压下率 高于70％，则冷轧带钢的变形抗力太大，超出机组的承载能力。因此在本发明所述制造方法的步骤(5)中控制冷轧压下率为60-70％。在一些实施方案中，冷轧板的厚度可在1.5-2.5mm的范围内，如1.5-2.0mm。
相应地，在上述步骤(6)中，采用了高温快速的连续退火工艺，控制均热温度为800-830℃，控制均热时间为100-150s，控制过时效温度在350-450℃之间，控制过时效时间为250-350s。可以与冷轧工艺相互配合，实现再结晶织构的形成与发展，从而获得均匀细小的铁素体晶粒，促进钢板强度和塑性的同时提升，同时渗碳体颗粒也可以在退火过程中重新溶解与析出，有利于钢板发挥抗鳞爆性能。
进一步地，在本发明所述的制造方法中，在步骤(2)中，加热温度为1100-1250℃。
在本发明所述的深冲内胆用冷轧搪瓷钢的制造方法中，在步骤(2)中，加热温度为1100-1250℃可得到均匀的奥氏体组织。如果加热温度低于1100℃，则钢的变形抗力大，热轧难以进行。相应地，若加热温度高于1250℃，钢坯在加热过程中容易发生脱碳、氧化铁皮厚重等问题。步骤(2)的加热时间可控制在120-200分钟，如130-180分钟。
进一步地，在本发明所述的制造方法中，在步骤(3)中，控制热轧的终轧温度为880-920℃，控制卷取温度为680-720℃。
在本发明所述的深冲内胆用冷轧搪瓷钢的制造方法中，在所述步骤(3)中，控制热轧的终轧温度为880-920℃。这是因为：如果终轧温度低于880℃，终轧进入两相区，得到块状先析铁素体和形变奥氏体转变的细小铁素体混合组织，会对钢板的力学性能产生不利的影响。而若终轧温度高于920℃，则形变奥氏体容易发生回复，不利于铁素体晶粒的细化。
此外，在本发明中采取较高的卷取温度，控制在卷取温度680-720℃之间，不仅有利于提高钢板的成形性能，还有利于第二相颗粒充分的弥散析出，可以有效提高钢的抗鳞爆性能。
进一步地，在本发明所述的制造方法中，在步骤(7)中，控制平整压下率为0.8-1.2％。
上述方案中，在所述步骤(7)中，控制平整压下率为0.8-1.2％进行平整后，不仅可以改善钢板的平直度和表面光洁度，并且钢板在存放一段时间后进行冲压时可不出现“屈服平台”。
本发明所述的深冲内胆用冷轧搪瓷钢及其制造方法相较于现有技术具有如下所 述的优点以及有益效果：
本发明所述的深冲内胆用冷轧搪瓷钢以低碳钢为基础，添加适量的硼、氮元素和微量钛、铌元素，辅助添加铜、铬等对搪瓷密着性能有提升的合金元素，获得均匀细小的铁素体+片层状和退化的珠光体的微观组织。其中，珠光体可以起到强化基体的作用，同时珠光体中的渗碳体颗粒作为不可逆氢陷阱，可以提高钢的抗鳞爆性能。在化学成分设计中，向钢中添加适量的硼和氮，二者结合生成弥散析出的BN颗粒，不仅可以作为有效的氢陷阱，显著提高钢的抗鳞爆性能，还可以有效提高铁素体生长的能力，以使钢获得良好的成形性。钢中添加微量钛能代替部分硼元素，与氮元素结合成TiN粒子，既降低BN给连铸坯带来的角裂风险，又有利于焊接性能。
该深冲内胆用冷轧搪瓷钢的铁素体晶粒度为7.5-8级，屈服强度为220-280MPa，延伸率为38-43％，氢穿透时间≥8min，经过至少850℃高温搪烧至少12min后的屈服强度≥200MPa。其具有良好的成形性、较高的高温搪烧后强度、优异的焊接性能和优良的抗鳞爆性能，可以有效适用于制作成形要求较高的电热水器搪瓷内胆等。
此外，本发明所述的制造方法采用了合适的控轧控冷工艺和高温快速连续退火工艺，实现硼、钛和铌的碳氮化物的弥散分布，使得采用本发明所述的制造方法所获得的深冲内胆用冷轧搪瓷钢得到均匀细小的铁素体+少量片层状和退化的珠光体组织，其中，片层状珠光体位于铁素体三叉晶界处，退化的珠光体的渗碳体颗粒位于铁素体晶界和晶粒内部，有效保证了制得的深冲内胆用冷轧搪瓷钢具有较高的高温搪烧后强度、高成形性和优良的抗鳞爆等特性。
附图说明
图1为实施例1的深冲内胆用冷轧搪瓷钢的显微组织图。
图2显示了实施例1的深冲内胆用冷轧搪瓷钢的微观组织中典型的珠光体形貌。
图3显示了实施例1的深冲内胆用冷轧搪瓷钢的微观组织中退化的珠光体组形貌。
图4显示了实施例1的深冲内胆用冷轧搪瓷钢中硼元素的存在位置。
具体实施方式
下面将结合具体的实施例和说明书附图对本发明所述的深冲内胆用冷轧搪瓷钢 及其制造方法做进一步的解释和说明，然而该解释和说明并不对本发明的技术方案构成不当限定。
实施例1-6和对比例1-2
表1列出了实施例1-6的深冲内胆用冷轧搪瓷钢和对比例1-2搪瓷钢中各化学元素质量百分比。
Figure PCTCN2021094111-appb-000001
本发明所述实施例1-6的深冲内胆用冷轧搪瓷钢和对比例1-2搪瓷钢均采用以下步骤制得：
(1)冶炼、精炼和连铸；
(2)板坯加热：加热温度为1100-1250℃，控制加热时间使板坯充分奥氏体化之后，进行热轧；
(3)热轧和卷取：控制热轧的终轧温度为880-920℃，轧后进行水冷、空冷或者缓冷，随后进行卷取，控制卷取温度为680-720℃；
(4)酸洗；
(5)冷轧：控制冷轧压下率为60-70％；
(6)连续退火：均热温度为800-830℃，均热时间为100-150s，过时效温度为350-450℃之间，过时效时间为250-350s；
(7)平整：控制平整压下率为0.8-1.2％。
表2-1和表2-2列出了实施例1-6的深冲内胆用冷轧搪瓷钢和对比例1-2搪瓷钢的具体工艺参数。
表2-1
Figure PCTCN2021094111-appb-000002
表2-2
Figure PCTCN2021094111-appb-000003
需要说明的是，实际操作过程中过时效温度是变化的，并非是稳定在一个固定值，而是在过时效时间段内，温度逐步降低，因此在表2-2的步骤(6)中的过时效温度在各实施例和对比例中呈现为一段范围值而不是点值。
将实施例1-6的深冲内胆用冷轧搪瓷钢和对比例1-2搪瓷钢进行各项性能测试，具体测试方法如下所述：
对实施例1-6和对比例1-2的冷轧搪瓷用钢进行高温模拟搪烧试验，搪烧温度为850℃，在炉时间为12min，测得其力学性能结果见表3。
对实施例1-6和对比例1-2的冷轧搪瓷用钢采用湿法涂搪涂搪工艺，首先钢板经过前处理获得适宜涂搪的表面，然后将铺满釉浆的钢板置于110℃的干燥炉内进行烘干，最后在高温炉内进行烧成，搪烧温度为850℃，在炉时间为12min，搪瓷后的钢板空冷至室温后，按照欧洲标准EN 10209-2013检测密着性能，钢球从750mm高度落下冲击搪瓷后的钢板表面，通过观察瓷釉与钢板的结合程度判断密着等级，并将搪瓷后的钢板放置72h以上，观察鳞爆情况。为了进一步衡量钢板的抗鳞爆性能，按照欧标EN 10209-2013对钢板的氢渗透值进行测试，换算成1mm厚的氢穿透时间。本文中，屈服强度和抗拉强度按照GB/T 228.1-2010测试，延伸率按照GB/T 228.1-2010测试。
表3列出了实施例1-6的深冲内胆用冷轧搪瓷钢和对比例1-2搪瓷钢的各项性能测试结果。
表3
Figure PCTCN2021094111-appb-000004
注：A1代表密着性能最好，A4代表密着性能最差。
结合表1至表3可以看出，对比例1的冷轧搪瓷用钢的B含量偏低，从而造成钢板中有效的氢陷阱数量不足，无法有效提升抗鳞爆性能，尤其开口均朝下的特殊机型在高温搪烧时容易出现鳞爆缺陷。对比例2的冷轧搪瓷用钢的Ti含量偏高，除了形成粗大的TiN和TiS颗粒外，还会析出细小弥散的TiC，造成强度上升，延伸率下降，此外，Ti在高温时容易形成TiO 2，导致钢板的密着等级大幅下降。
由表3可看出，本发明实施例1-6的深冲内胆用冷轧搪瓷钢中珠光体的相比例均＜3％，铁素体晶粒度均为7.5-8级，其纵向屈服强度均在220-280MPa之间，延伸率在38.0-43.0％之间，并且经过至少850℃高温搪烧至少12min后的屈服强度≥ 200MPa。此外，钢板经过单面湿法涂搪之后，搪瓷层与钢板的结合程度良好，为A1级，且长时间放置无鳞爆现象产生。经测试，钢板的氢穿透值(换算成1mm厚)≥8min，超过了欧标EN 10209-2013中规定的门槛值6.7min，由此可见本发明各实施例的深冲内胆用冷轧搪瓷钢在双面涂搪的情况下也不会发生鳞爆，具有优异的抗鳞爆性能。
图1为实施例1的深冲内胆用冷轧搪瓷钢的显微组织图。
如图1所示，在本发明所述的实施例1的深冲内胆用冷轧搪瓷钢中，其微观组织为多边形铁素体和少量片层状和退化的珠光体，片层状珠光体分布于铁素体的三叉晶界处，退化的珠光体的渗碳体颗粒分布于铁素体晶界和晶粒内部。
图2显示了实施例1的深冲内胆用冷轧搪瓷钢的微观组织中典型的珠光体形貌。
图3显示了实施例1的深冲内胆用冷轧搪瓷钢的微观组织中退化的珠光体组形貌。
结合图2和图3可以看出，在本发明所述的实施例1的深冲内胆用冷轧搪瓷钢中，珠光体除了典型的片层状珠光体，还有一些退化的珠光体组织，其渗碳体不连续、趋向于椭圆形或者长条形，这可能是由于B的添加降低了钢中固溶碳的含量，因此无法形成完整的片层状珠光体结构。由图3可以看出，退化的珠光体渗碳体颗粒存在于铁素体晶界和晶粒内部，研究表明，BN或者碳化硼在晶界偏聚，阻碍了碳化物在晶界上析出，倾向于在基体上析出。
图4显示了实施例1的深冲内胆用冷轧搪瓷钢中硼元素的存在位置。
在本发明实施例1的深冲内胆用冷轧搪瓷钢中，钢中B元素不以单质原子的形式存在，而是与N元素或者C元素结合成复杂化合物BN或者碳化硼颗粒，偏聚在晶界处或者晶内的渗碳体上。
需要注意的是，以上所列举实施例仅为本发明的具体实施例。显然本发明不局限于以上实施例，随之做出的类似变化或变形是本领域技术人员能从本发明公开的内容直接得出或者很容易便联想到的，均应属于本发明的保护范围。

Claims (14)

  1. 一种深冲内胆用冷轧搪瓷钢，其特征在于，其含有质量百分比如下的下述化学元素：
    C：0.02-0.06％，0＜Si≤0.08％，Mn：0.1-0.7％，P≤0.055％，S≤0.03％，Al：0.01-0.07％，N：0.002-0.010％，B：0.002-0.009％，Ti：0.002-0.015％，Nb：0.002-0.012％，Cr：0.01-0.08％，以及Cu、Ni和Mo的至少其中一种，其中Cu+Ni+Mo≤0.40％。
  2. 如权利要求1所述的深冲内胆用冷轧搪瓷钢，其特征在于，其各化学元素质量百分比为：
    C：0.02-0.06％，0＜Si≤0.08％，Mn：0.1-0.7％，P≤0.055％，S≤0.03％，Al：0.01-0.07％，N：0.002-0.010％，B：0.002-0.009％，Ti：0.002-0.015％，Nb：0.002-0.012％，Cr：0.01-0.08％，以及Cu、Ni和Mo的至少其中一种，其中Cu+Ni+Mo≤0.40％，余量为Fe及其他不可避免的杂质。
  3. 如权利要求1或2所述的深冲内胆用冷轧搪瓷钢，其特征在于，其各化学元素质量百分含量满足下述各项的至少其中之一：C：0.02-0.04％，0＜Si≤0.05％，Mn：0.2-0.5％，P≤0.035％，S≤0.015％，Al：0.01-0.04％，N：0.003-0.008％，B：0.0025-0.0065％，Ti：0.002-0.008％，Nb：0.002-0.006％，Cr：0.02-0.08％，以及Cu、Ni和Mo的至少其中一种，其中Cu+Ni+Mo≤0.25％。
  4. 如权利要求1-3中任一项所述的深冲内胆用冷轧搪瓷钢，其特征在于，其中B和N的质量百分比含量满足：B/N＝0.8-1.5。
  5. 如权利要求1-4中任一项所述的深冲内胆用冷轧搪瓷钢，其特征在于，各化学元素还满足下列各式的至少其中之一：
    0.4≤B×N×10 5≤10；
    -2≤Ti×(N-14/11B)×10 5≤12。
  6. 如权利要求1-5中任一项所述的深冲内胆用冷轧搪瓷钢，其特征在于，其微观组织为均匀细小的铁素体、片层状的珠光体和退化的珠光体，其中片层状的珠光体和退化的珠光体的相比例之和＜3％；其中所述珠光体中的渗碳体颗粒与铁素体之间存在空位。
  7. 如权利要求6所述的深冲内胆用冷轧搪瓷钢，其特征在于，其中片层状的珠光 体位于铁素体三叉晶界处，退化的珠光体中的渗碳体颗粒位于铁素体晶界和晶粒内部。
  8. 如权利要求6所述的深冲内胆用冷轧搪瓷钢，其特征在于，其中铁素体晶粒度为7.5-8级。
  9. 如权利要求1-8中任一项所述的深冲内胆用冷轧搪瓷钢，其特征在于，其性能满足下述各项的至少其中之一：屈服强度为220-280MPa，延伸率为38-43％，氢穿透时间≥8min，经过至少850℃高温搪烧至少12min后的屈服强度≥200MPa。
  10. 如权利要求1和4-9中任一项所述的深冲内胆用冷轧搪瓷钢，其特征在于，Cu：0.005-0.02％，Ni：≤0.02％，和Mo：≤0.02％，Cu+Ni+Mo≤0.05％。
  11. 一种如权利要求1-10中任一项所述的深冲内胆用冷轧搪瓷钢的制造方法，其特征在于，包括步骤：
    (1)冶炼、精炼和连铸；
    (2)板坯加热；
    (3)热轧和卷取；
    (4)酸洗；
    (5)冷轧：控制冷轧压下率为60-70％；
    (6)连续退火：均热温度为800-830℃，均热时间为100-150s，过时效温度为350-450℃之间，过时效时间为250-350s；
    (7)平整。
  12. 如权利要求11所述的制造方法，其特征在于，在步骤(2)中，加热温度为1100-1250℃。
  13. 如权利要求11所述的制造方法，其特征在于，在步骤(3)中，控制热轧的终轧温度为880-920℃，控制卷取温度为680-720℃。
  14. 如权利要求11所述的制造方法，其特征在于，在步骤(7)中，控制平整压下率为0.8-1.2％。
PCT/CN2021/094111 2020-05-18 2021-05-17 一种深冲内胆用冷轧搪瓷钢及其制造方法 WO2021233247A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2022570374A JP2023526409A (ja) 2020-05-18 2021-05-17 深絞り内釜用冷間圧延エナメル鋼およびその製造方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010418537.5A CN113684413B (zh) 2020-05-18 2020-05-18 一种深冲内胆用冷轧搪瓷钢及其制造方法
CN202010418537.5 2020-05-18

Publications (1)

Publication Number Publication Date
WO2021233247A1 true WO2021233247A1 (zh) 2021-11-25

Family

ID=78575443

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/094111 WO2021233247A1 (zh) 2020-05-18 2021-05-17 一种深冲内胆用冷轧搪瓷钢及其制造方法

Country Status (3)

Country Link
JP (1) JP2023526409A (zh)
CN (1) CN113684413B (zh)
WO (1) WO2021233247A1 (zh)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114395688A (zh) * 2021-12-09 2022-04-26 安阳钢铁集团有限责任公司 一种低碳搪瓷钢的生产工艺
CN115110000A (zh) * 2022-06-28 2022-09-27 马鞍山钢铁股份有限公司 一种330MPa级冷轧搪瓷用钢及其生产方法
CN115491599A (zh) * 2022-09-19 2022-12-20 马鞍山钢铁股份有限公司 一种400MPa级双面搪瓷用冷轧钢板及其生产方法
CN115522129A (zh) * 2022-09-30 2022-12-27 武汉钢铁有限公司 330MPa级宽幅薄规格高质量热轧搪瓷钢及生产方法
CN115537653A (zh) * 2022-09-09 2022-12-30 首钢集团有限公司 一种热轧搪瓷钢板及其制备方法
CN115612941A (zh) * 2022-10-28 2023-01-17 武汉钢铁有限公司 高强搪瓷钢及其使用低温退火工艺生产的冷轧制造方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114395690A (zh) * 2021-12-09 2022-04-26 安阳钢铁集团有限责任公司 一种300MPa级高强搪瓷钢的生产工艺
CN114657473A (zh) * 2022-02-24 2022-06-24 山东钢铁集团日照有限公司 一种深冲用冷轧搪瓷钢及其制备方法
CN115181902B (zh) * 2022-05-12 2023-08-25 马鞍山钢铁股份有限公司 一种用于双面搪瓷的冷轧低合金钢板及其制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102251192A (zh) * 2010-05-19 2011-11-23 宝山钢铁股份有限公司 一种搪瓷钢及其制造方法
CN104928577A (zh) * 2015-06-18 2015-09-23 宝山钢铁股份有限公司 一种具有高扩孔率和优良涂搪性能的钢板及其制造方法
CN105177411A (zh) * 2015-08-07 2015-12-23 华北理工大学 适宜连续退火生产的含硼冷轧搪瓷钢及其制造方法
CN110079731A (zh) * 2019-04-30 2019-08-02 马鞍山钢铁股份有限公司 一种260MPa级搪瓷用冷轧钢板及其生产方法
WO2019221286A1 (ja) * 2018-05-17 2019-11-21 日本製鉄株式会社 鋼板およびほうろう製品

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL2767602T3 (pl) * 2013-02-14 2019-10-31 Thyssenkrupp Steel Europe Ag Walcowany na zimno płaski wyrób stalowy do zastosowań w głębokim tłoczeniu i sposoby jego wytwarzania
CN104419874A (zh) * 2013-09-05 2015-03-18 鞍钢股份有限公司 抗鳞爆性能优异的热轧双面搪瓷钢及其制造方法
KR102075222B1 (ko) * 2017-12-26 2020-02-07 주식회사 포스코 재질편차가 적고, 신장플랜지성 및 실수율이 우수한 고강도 냉연강판 및 그 제조방법
CN110777301B (zh) * 2018-07-30 2021-05-14 宝山钢铁股份有限公司 一种冷轧搪瓷钢及其制造方法
CN110273106B (zh) * 2019-07-30 2020-12-18 马鞍山钢铁股份有限公司 一种260MPa级冷轧连退搪瓷钢及其生产方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102251192A (zh) * 2010-05-19 2011-11-23 宝山钢铁股份有限公司 一种搪瓷钢及其制造方法
CN104928577A (zh) * 2015-06-18 2015-09-23 宝山钢铁股份有限公司 一种具有高扩孔率和优良涂搪性能的钢板及其制造方法
CN105177411A (zh) * 2015-08-07 2015-12-23 华北理工大学 适宜连续退火生产的含硼冷轧搪瓷钢及其制造方法
WO2019221286A1 (ja) * 2018-05-17 2019-11-21 日本製鉄株式会社 鋼板およびほうろう製品
CN110079731A (zh) * 2019-04-30 2019-08-02 马鞍山钢铁股份有限公司 一种260MPa级搪瓷用冷轧钢板及其生产方法

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114395688A (zh) * 2021-12-09 2022-04-26 安阳钢铁集团有限责任公司 一种低碳搪瓷钢的生产工艺
CN115110000A (zh) * 2022-06-28 2022-09-27 马鞍山钢铁股份有限公司 一种330MPa级冷轧搪瓷用钢及其生产方法
CN115110000B (zh) * 2022-06-28 2024-01-19 马鞍山钢铁股份有限公司 一种330MPa级冷轧搪瓷用钢及其生产方法
CN115537653A (zh) * 2022-09-09 2022-12-30 首钢集团有限公司 一种热轧搪瓷钢板及其制备方法
CN115537653B (zh) * 2022-09-09 2023-11-10 首钢集团有限公司 一种热轧搪瓷钢板及其制备方法
CN115491599A (zh) * 2022-09-19 2022-12-20 马鞍山钢铁股份有限公司 一种400MPa级双面搪瓷用冷轧钢板及其生产方法
CN115491599B (zh) * 2022-09-19 2023-07-25 马鞍山钢铁股份有限公司 一种400MPa级双面搪瓷用冷轧钢板及其生产方法
CN115522129A (zh) * 2022-09-30 2022-12-27 武汉钢铁有限公司 330MPa级宽幅薄规格高质量热轧搪瓷钢及生产方法
CN115522129B (zh) * 2022-09-30 2023-10-20 武汉钢铁有限公司 330MPa级宽幅薄规格高质量热轧搪瓷钢及生产方法
CN115612941A (zh) * 2022-10-28 2023-01-17 武汉钢铁有限公司 高强搪瓷钢及其使用低温退火工艺生产的冷轧制造方法

Also Published As

Publication number Publication date
CN113684413B (zh) 2022-06-28
CN113684413A (zh) 2021-11-23
JP2023526409A (ja) 2023-06-21

Similar Documents

Publication Publication Date Title
WO2021233247A1 (zh) 一种深冲内胆用冷轧搪瓷钢及其制造方法
JP5135868B2 (ja) 缶用鋼板およびその製造方法
EP3795710A1 (en) Hot-rolled thick h-beam with yield strength grade of 500 mpa and preparation method therefor
CN113481430B (zh) 一种扩孔性能增强的800MPa级含硼热镀锌双相钢及其生产方法
CN111057945B (zh) 一种500MPa级强韧耐候桥梁钢及其制备方法
WO2019218657A1 (zh) 一种屈服强度460MPa级热轧高韧性耐低温H型钢及其制备方法
CN111996468B (zh) 一种搪瓷钢及其制备方法和应用
CN110343964B (zh) 一种屈服强度大于500MPa的搪瓷用冷轧钢板及其生产方法
CN110079731B (zh) 一种260MPa级搪瓷用冷轧钢板及其生产方法
WO2022022040A1 (zh) 一种355MPa级别海洋工程用耐低温热轧H型钢及其制备方法
CN110714165B (zh) 一种320MPa级家电面板用冷轧薄板及其生产方法
CN113832399A (zh) 一种经济型抗硫化氢腐蚀管线钢及其生产方法
CN114480975B (zh) 一种经济型x65级耐酸管线钢板卷及其制造方法
CN109097681B (zh) 一种高强度低夹杂汽车钢板及其连铸过程电磁搅拌工艺
CN110093563B (zh) 一种深冲用途的搪瓷用冷轧钢板及其生产方法
WO2024001078A1 (zh) 一种80mm厚690MPa级超高强韧海工钢板及其制备方法
CN111621704A (zh) 一种硬度HR30Tm在55±4内的含硼和铬的超低碳镀锡板及其制造方法
JP2002363685A (ja) 低降伏比高強度冷延鋼板
CN113046636A (zh) 一种高耐蚀无时效食品罐用钢及制备方法
JPH06179922A (ja) 深絞り用高張力薄鋼板の製造法
JP2004197156A (ja) 耐二次加工脆性に優れた高強度薄鋼板およびその製造方法
JP3872595B2 (ja) 面内異方性が小さく成形性に優れた冷延鋼板
WO2023093798A1 (zh) 一种双面搪瓷内胆用高强度冷轧钢板及其制造方法
CN110747393B (zh) 一种atm自动取款机高强钢板及其制造方法
CN117684088A (zh) 钢板及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21807659

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022570374

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21807659

Country of ref document: EP

Kind code of ref document: A1