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CN-116814924-B - Hot forming steel part with coating and preparation method thereof

CN116814924BCN 116814924 BCN116814924 BCN 116814924BCN-116814924-B

Abstract

The application relates to a hot-formed steel part with a coating and a preparation method thereof, belonging to the technical field of steel preparation; the method comprises the steps of selecting aluminum-silicon coating hot forming steel according to part design, heating the aluminum-silicon coating hot forming steel to obtain steel to be stamped, stamping the steel to be stamped, and then carrying out pressure maintaining quenching to obtain the part, wherein the heating comprises a prealloying stage, an austenitizing stage and a heating stage, and the prealloying stage is used for prealloying at a relatively low temperature, so that the iron element of the substrate is diffused into the coating, and the melting point of the coating is improved. Meanwhile, the temperature is relatively low, so that the excessive melting of the coating is avoided, and the phenomenon of sticking to rollers is relieved or even avoided. The austenitizing stage makes the aluminum-silicon coating hot forming steel fully austenitized, thereby being beneficial to the performance of parts. The temperature rising stage can ensure the tapping temperature of the aluminum-silicon coating hot forming steel, and is beneficial to subsequent stamping forming.

Inventors

  • MA WENYU
  • LIU YU
  • WANG BAOCHUAN
  • HAN LONGSHUAI
  • LI XUETAO
  • ZHENG XUEBIN
  • XU DECHAO
  • ZHANG BOMING
  • ZHANG YONGQIANG
  • HUANG JUN
  • LI YADONG
  • YAO YE

Assignees

  • 首钢集团有限公司

Dates

Publication Date
20260512
Application Date
20230627

Claims (7)

  1. 1. A method of making a coated hot formed steel part, the method comprising: Selecting the aluminum-silicon coating hot forming steel according to the design of the part; Heating the aluminum-silicon coating hot-formed steel to obtain steel to be stamped; Stamping the steel to be stamped, and then carrying out pressure maintaining quenching to obtain a part; Wherein the heating includes a prealloying stage to diffuse iron element in the matrix of the aluminum-silicon plated hot formed steel to the plating layer, an austenitizing stage to fully austenitize the aluminum-silicon plated hot formed steel, and a heating stage to facilitate the press forming; the temperature T1 in the prealloying stage is 598 ℃ less than or equal to T1<860 ℃, the temperature T2 in the austenitizing stage is 860 ℃ less than or equal to T2<930 ℃, and the temperature T3 in the heating stage is 930 ℃ less than or equal to T3 ℃ less than or equal to 960 ℃; the relation between the time t1 of the prealloying stage and the total time t of heating satisfies that 0% < t1/t is less than or equal to 47%; The relation between the time t2 of the austenitizing stage and the total time t of the heating satisfies that 0% < t2/t is less than or equal to 40%; The relation between the time t3 of the heating stage and the total heating time t is 20 percent-t 3/t-45 percent; The relation of the total time t of heating, the time t1 of the prealloying stage, the time t2 of the austenitizing stage and the time t3 of the heating stage satisfies t=t1+t2+t3; The total heating time t is 180-1200 s.
  2. 2. The method of producing a hot-formed steel part with a coating according to claim 1, further comprising detecting a fracture of the part, and if a fracture occurs, adjusting the temperature of the warm-up stage; when the part has cracks visible to naked eyes, the temperature T3 in the heating stage is adjusted to be 950-960 ℃ or more; detecting a thinning condition when the part has cracks invisible to naked eyes; When the maximum thinning rate x of the part meets x being more than or equal to 30%, adjusting the temperature T3 in the heating stage to 950 ℃; When the maximum thinning rate x of the part meets 15% -x <30%, the temperature T3 in the heating stage is adjusted to 940-950 ℃; when the maximum thinning rate x of the part meets 12 percent or more and x is less than 15 percent, adjusting the temperature T3 in the heating stage to 930-940 ℃; When the maximum thinning rate x of the part meets x <12%, the temperature T3 of the heating stage is adjusted to 930 ℃.
  3. 3. The method for producing a hot-formed steel part with a coating according to claim 1, wherein when the maximum reduction rate x of the part satisfies 15% to x <30%, the temperature T3 in the temperature raising stage is adjusted to satisfy T3= (200/3) x+930, and/or When the maximum thinning rate x of the part meets 12% +.x <15%, the temperature T3 in the temperature raising stage is adjusted to meet T3= (1000/3) x+890.
  4. 4. The method of producing a coated hot-formed steel part according to claim 1, further comprising the step of forming the aluminum-silicon coated hot-formed steel in the form of a sheet, a patch, or a splice welding.
  5. 5. The method for producing a plated thermoformed steel part according to claim 1, wherein when the form of the aluminum-silicon plated thermoformed steel is a tailor-welded type, a welding mode is selected according to a plating thickness of the aluminum-silicon plated thermoformed steel; when the coating thickness H of the aluminum silicon coating hot forming steel meets H less than or equal to 10 mu m, the welding mode is direct laser splice welding; When the coating thickness H of the aluminum silicon coating hot forming steel meets 10< H less than or equal to 20 mu m, the welding mode is direct laser splice welding or direct laser filler wire welding; When the coating thickness H of the aluminum silicon coating hot forming steel meets 20< H less than or equal to 35 mu m, the welding mode is direct laser filler wire welding or indirect laser filler wire welding; When the coating thickness H of the aluminum silicon coating hot forming steel meets H >35 mu m, the welding mode is indirect laser filler wire welding.
  6. 6. The method for producing a plated hot-formed steel part according to claim 1, wherein the cooling rate of the dwell quenching is not less than 27 ℃.
  7. 7. A coated hot-formed steel part, characterized in that the part is produced by the method for producing a coated hot-formed steel part according to any one of claims 1 to 6.

Description

Hot forming steel part with coating and preparation method thereof Technical Field The application relates to the technical field of steel preparation, in particular to a hot-formed steel part with a coating and a preparation method thereof. Background The aluminum-silicon coating hot forming steel is widely applied in the hot stamping field at present, and the aluminum-silicon coating hot forming steel with various coating thicknesses at present. In the heating link in the hot stamping process, there are some problems, for example, because the surface of the plate material is provided with an aluminum silicon coating, the phenomenon of sticking to the roller easily occurs when the plate material moves in the roller hearth furnace, the coating can adhere to the roller after melting, so that the accumulation of the roller is caused, and the roller needs to be stopped for maintenance and replacement when the roller is seriously required. Meanwhile, austenitizing of the plate needs to be realized in the heating process, and after austenitizing of the plate, components in the plate also need to be uniformly diffused and organized. The existence of the strip-shaped tissue can be avoided only when the tissue is uniform in the heating process of the plate material, and the uniformity of the performance of the stamped part is ensured. The degree of austenitization is directly affected by the heating temperature and heating time. When the sheet is discharged after heating, the sheet needs to be transferred to a die for stamping, and the risk of cracking is caused during stamping. If the temperature of the sheet is low during press forming, the formability of the sheet is lowered and cracking is likely to occur. Disclosure of Invention The application provides a hot-formed steel part with a coating and a preparation method thereof, which are used for solving the problems of heating and hot stamping in the hot stamping process. In a first aspect, the present application provides a method of producing a plated thermoformed steel part, the method comprising: Selecting the aluminum-silicon coating hot forming steel according to the design of the part; Heating the aluminum-silicon coating hot-formed steel to obtain steel to be stamped; Stamping the steel to be stamped, and then carrying out pressure maintaining quenching to obtain a part; Wherein the heating includes a prealloying stage to diffuse iron element in the matrix of the aluminum-silicon plated hot formed steel to the plating layer, an austenitizing stage to fully austenitize the aluminum-silicon plated hot formed steel, and a heating stage to facilitate the press forming. As an alternative embodiment, the temperature T1 of the prealloying stage is such that 598 ℃ C. Ltoreq.T1 <860 ℃ C, and/or The austenitizing stage temperature T2 is such that 860≤T2 <930 ℃, and/or The temperature T3 in the heating stage is 930-960 ℃ and T3 is not less than. As an alternative embodiment, the relation between the time t1 of the prealloying stage and the total time t of the heating satisfies 0% < t 1/t≤47%, and/or The relation between the time t2 of the austenitizing stage and the total time t of the heating is such that 0% < t2/t < 40%, and/or The relation between the time t3 of the heating stage and the total time t of the heating is 20% to less than or equal to t3/t to less than or equal to 45%, and/or The relation of the total time t of heating, the time t1 of the prealloying stage, the time t2 of the austenitizing stage and the time t3 of the heating stage satisfies t=t1+t2+t3. As an alternative embodiment, the total time t of heating is 180-1200 s. As an alternative embodiment, the method further comprises detecting the breakage of the part, and if the breakage occurs, adjusting the temperature of the heating stage; when the part has cracks visible to naked eyes, the temperature T3 in the heating stage is adjusted to be 950-960 ℃ or more; detecting a thinning condition when the part has cracks invisible to naked eyes; When the maximum thinning rate x of the part meets x being more than or equal to 30%, adjusting the temperature T3 in the heating stage to 950 ℃; When the maximum thinning rate x of the part meets 15% -x <30%, the temperature T3 in the heating stage is adjusted to 940-950 ℃; when the maximum thinning rate x of the part meets 12 percent or more and x is less than 15 percent, adjusting the temperature T3 in the heating stage to 930-940 ℃; When the maximum thinning rate x of the part meets x <12%, the temperature T3 of the heating stage is adjusted to 930 ℃. As an alternative embodiment, when the maximum reduction rate x of the part satisfies 15% +≤x <30%, then the temperature T3 of the heating stage is adjusted to satisfy T3= (200/3) x+930, and/or When the maximum thinning rate x of the part meets 12% +.x <15%, the temperature T3 in the temperature raising stage is adjusted to meet T3= (1000/3) x+890. As an alternative embodiment, the method further comprises th