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CN-116117007-B - Processing technology for non-indentation bending molding of mirror surface stainless steel plate

CN116117007BCN 116117007 BCN116117007 BCN 116117007BCN-116117007-B

Abstract

The invention discloses a processing technology for non-indentation bending molding of a mirror surface stainless steel plate, and belongs to the technical field of mirror surface stainless steel bending molding. A technology for bending the stainless steel plate without indentation includes such steps as putting the plate on top of lower die body 30, pressing the plate by upper die body, and rolling the lower die body 30 by indirect pressure relative to limit region 20 to bend the stainless steel plate to a designed angle. Can finish the stainless steel molding of the mirror surface for tens of thousands times and ensure the molding precision of the plate after tens of thousands times.

Inventors

  • WANG KEWEN
  • ZHANG YIFAN

Assignees

  • 安徽力源数控刃模具制造有限公司

Dates

Publication Date
20260505
Application Date
20221226

Claims (5)

  1. 1. The processing technology of the mirror surface stainless steel plate indentation-free bending forming die comprises a forming die, wherein the forming die comprises a lower die holder (10), a limiting area (20) is distributed at the top of the lower die holder (10), two lower die bodies (30) which are rotationally distributed relative to the limiting area (20) are symmetrically distributed at the limiting area (20), tension springs (40) are installed at the bottoms of the two lower die bodies (30), and the bottoms of the tension springs (40) are fixed on the lower die holder (10) through locking bolts; The die is characterized in that the die holder (10) comprises, by mass, 0.17-0.52 part of C, 0.17-0.31 part of Si, 5.44-8.15 parts of Mn, 7.13-11.58 parts of Cr, 4.15-6.55 parts of Ni, less than or equal to 0.02 part of P, less than or equal to 0.02 part of S, 0.021-0.038 part of Nb, 0.012-0.017 part of Y, 0.07-0.23 part of Ti, 0.08-0.14 part of B, and the balance of Fe and impurities; Wherein ti=0.21 (nb+y) +0.34 (c+s); Wherein si=0.21b+0.015 (ni+cr); The lower die body (30) is processed through the following steps of carrying out nitriding post-oxidation treatment on steel of the lower die body (30), preparing deposition liquid by the ratio of tetraethoxysilane, ammonia water with the mass fraction of 25% -28%, pure water and absolute ethyl alcohol according to the ratio of 1:4-5:7-8:3-4, placing the lower die body (30) subjected to heat treatment into the deposition liquid with the volume of 25-35 times, carrying out ultrasonic reaction for 2-4 hours at 45-60 Hz, adding tetraethoxysilane with the volume of 0.02-0.08 times, carrying out ultrasonic reaction for 2-4 hours at 45-60 Hz, taking out the product, washing the product for 2 times by using 250mL of pure water, washing the product by using 180mL of 95% ethanol for 2 times, drying the product at 85-95 DEG, placing the product in a reactor, vacuumizing the reactor to enable the pressure to reach 3.5-4.5 MPa, introducing tetraethoxysilane with the temperature of 0.05-0.12 times of gaseous titanium tetrachloride, vacuumizing the reactor to enable the pressure to reach 3.5-4.5 MPa, introducing mixed gas to enable the pressure to reach the temperature of 95MPa, and then carrying out the temperature is kept at the temperature of 1200-5-80 ℃ for the die body is reached after the temperature is reached to be 800-30 h.
  2. 2. The processing technology of the non-indentation bending forming die for the mirror surface stainless steel plate according to claim 1, wherein the components of the lower die holder (10) further comprise 0.013-0.023 part of alloy steel modifier, and the alloy steel modifier comprises 32-45 parts of Al 2 O 3 , 26-31 parts of Al, 16-28 parts of CaF 2 , 5-15 parts of MgO and 2-5 parts of LaNi 5 .
  3. 3. The processing technology of the mirror surface stainless steel plate indentation-free bending forming die according to claim 2, characterized in that the processing steps of the lower die holder (10) are as follows: (1) Smelting Smelting by adopting the material of claim 2, and adding 0.013-0.023 part of alloy steel modifier during tapping to prepare a forging blank of a lower die holder (10) material; (2) Destressing annealing treatment for forging and forgings Heating the obtained forging blank to 1250-1450 ℃ for forging, and carrying out final forging at 950-970 ℃ to obtain a forging piece, annealing the obtained forging piece through an annealing furnace at 680-750 ℃ for 4-5 hours, cooling to 200-300 ℃ in the annealing furnace, preserving heat for 0.6-1.2 hours, and then cooling to normal temperature; (3) Preliminary working and heat treatment of forgings Heating the die obtained by machining to 530-550 ℃ and then preserving heat for 3-4 hours, then heating to 750-800 ℃ and then preserving heat for 1-2 hours, then heating to 940-960 ℃, preserving heat for 30-45 minutes and then quenching, cooling and then carrying out cryogenic treatment, wherein the cryogenic treatment temperature is-220 ℃ to-230 ℃, the temperature is maintained for 1-2 hours, the die is restored to normal temperature in air, primary tempering is carried out, the tempering temperature is 130-140 ℃, the die is placed for 1-1.5 hours after being cooled to normal temperature, and secondary tempering is carried out, and the tempering temperature is 150-170 ℃; (4) Deep processing and processing center treatment of lower die holder (10) And (3) removing an oxide layer on the surface of the die after heat treatment, assembling the die on a grinding machine, grinding, reserving a margin of 0.7-1 mm on each surface, standing for at least 1 day, grinding the other surfaces except the cambered surface to a required size again, putting a workpiece obtained by deep processing into a machining center, milling the cambered surface of the die by using a milling cutter, and removing the margin of 0.7-1 mm.
  4. 4. The processing technology of the stainless steel mirror plate indentation-free bending forming die according to claim 1, wherein the lower die body (30) comprises a guide body (31) and a limiting body (32) which are integrally arranged, the guide body (31) and the limiting area (20) are rotationally arranged, and the limiting body (32) is lapped on the top of the lower die holder (10) in a natural state.
  5. 5. The processing technology of the non-indentation bending forming die for the mirror surface stainless steel plate according to claim 1, wherein a notch for installing a tension spring (40) is arranged on the side part of the lower die holder (10), an installation groove (11) is arranged on the side bottom, an installation plate (12) is fixedly installed inside the installation groove (11) through bolts, and a pin (13) for installing the bottom end of the tension spring (40) is arranged on the installation plate (12).

Description

Processing technology for non-indentation bending molding of mirror surface stainless steel plate Technical Field The invention relates to the technical field of mirror surface stainless steel bending forming, in particular to a processing technology of non-indentation bending forming of a mirror surface stainless steel plate and a processing technology of a die adopted during forming. Background The traditional bending die generally adopts a lower die and an upper die, and the lower die adopts a structure with a specific shape to finish bending and forming of the plate. However, the original bending structure can cause the surface of the plate to be indented, and particularly, some plates with special surface requirements cannot use the die, such as mirror-surface stainless steel bending pieces, and the surface of the plate needs to be free of indentation. Retrieve a combination formula does not have rotation of indentation and turns over board mould, publication number CN217889144U, including the mould body, the mould body includes down the die body to and the symmetry sets up in two turns over boards at die body top down, be equipped with coupling assembling down between die body and the board, coupling assembling includes the extension spring of fixed mounting in die body inside down, and connects the pull rod on turning over the board, the extension spring is including the spring portion that is located the inside lower extreme of die body down, and sets up the connecting portion at spring portion both ends, the both ends of extension spring are connected fixedly with the pull rod respectively. The utility model adopts the lower die body provided with two symmetrical arc grooves to match with the left and right turning plates, and then carries out limit fixation through the connecting component, the workpiece is contacted with the plane of the turning plate in the process of pressing the workpiece into the lower die body by the upper die, and the turning plate rotates in the lower die body, so that the workpiece and the turning plate do not slide relatively, thereby eliminating the indentation and scratch on the surface of the workpiece caused by extrusion. However, the technology turns over the board and appears great wearing and tearing easily after shaping panel thousands times, in case it turns over the board and can't reach design angle when panel shaping after appearing serious wearing and tearing, can make panel shaping angle can't guarantee still can keep its angle accurate after tens of thousands times shaping like this, causes needs a bending mould and panel's processing technology that can accomplish tens of thousands times shaping and guarantee panel shaping precision. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a processing technology for forming a mirror surface stainless steel plate by bending without indentation. In order to achieve the above purpose, the present invention adopts the following technical scheme: The processing technology for the non-indentation bending forming of the mirror surface stainless steel plate comprises a lower die holder, wherein a limiting area is distributed at the top of the lower die holder, two lower die bodies which are rotationally distributed relative to the limiting area are symmetrically distributed at the limiting area, tension springs are installed at the bottoms of the two lower die bodies, and the bottoms of the tension springs are fixed on the lower die holder through locking bolts; The lower die body is subjected to nitriding post-oxidation treatment, tetraethoxysilane, ammonia water with the mass fraction of 25% -28%, pure water and absolute ethyl alcohol are prepared into a deposition solution according to the proportion of 1: (4-5): (7-8): (3-4), the lower die body after heat treatment is placed in the deposition solution with the volume of 25-35 times, ultrasonic reaction is carried out for 2-4 hours at 45-60 Hz, nano yttrium oxide with the volume of 0.02-0.08 times of tetraethoxysilane is added, ultrasonic reaction is carried out for 2-4 hours at 45-60 Hz, 250mL of pure water is taken out and used for cleaning for 2 times, 180mL of 95% ethanol is used for cleaning for 2 times, drying is carried out for 4-6 hours at 85-95 DEG, then the lower die body is placed in a reactor, the pressure is up to 3.5-4.5 MPa, the gaseous state with the volume of 0.05-0.12 times of tetraethoxysilane is introduced, the temperature of the reactor is raised to 330-350 DEG, the pressure is up to 3.5-4.5 MPa again, the mixed reducing gas is introduced to the pressure is up to 75-95 MPa, and the temperature of the lower die body is 800-8 hours after the mixed reducing gas is reached. The following improvements are made on the basis of the above embodiments, wherein the mixed reducing gas comprises one or more of hydrogen and silane in addition to methane. On the basis of the embodiment, the lower die holder 10 is i