CN101912910A - A Deep Drawing Method of Low Plasticity and Low Hardening Index Thin Plate - Google Patents

Abstract

The invention relates to a deep-drawing method for thin plates with low plasticity and low hardening index. The technical solution is: first place a thin plate with low plasticity and low hardening index and two industrial pure aluminum plates with the same plane size as the thin plate separately in a resistance furnace, heat to 80 ° C ~ T for recrystallization, and keep warm for 0.1 to 3 hours; 4 to 6 minutes before the thin plate and industrial pure aluminum plate are released from the furnace, the drawing die is preheated to the temperature when the thin plate and industrial pure aluminum plate are released; then the thin plate with low plasticity and low hardening index and industrial pure aluminum The aluminum plate is quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, aligned up and down; it is placed on the drawing die for drawing, and the relative movement speed of the punch and die during drawing is 0.01mm/s～30mm/s. The invention has the characteristics of high yield, smoothness, no crack, no wrinkle and high efficiency.

Description

A Deep Drawing Method of Low Plasticity and Low Hardening Index Thin Plate

technical field

The invention belongs to the technical field of thin plates. In particular, it relates to a deep-drawing method for thin plates with low plasticity and low hardening index.

Background technique:

A material is considered low plastic when its elongation at room temperature is less than 12%. Low-plastic materials are difficult to deform during rolling and subsequent deep drawing, and are prone to cracks and breaks, making it difficult to form, which has become the main obstacle restricting its smooth processing. However, since low plastic materials have their own advantages, such as high strength and high elastic modulus, many industrial fields need to use these special performance properties. In practice, because many parts have complex shapes, they need to be formed by deep drawing or other methods. However, due to the low plasticity of low-plastic materials, it is more difficult to process if the sheet is very thin.

In addition, the hardening index of the material is also a main index to measure the stamping or deep drawing performance of the material, indicating the ability of the material to resist local deformation. In the stamping or deep drawing process of the thin plate, the order of contact between the sheet material and the die is not the same. If a cylinder is drawn deep with a die, then when the punch goes down, the lower circumference of the punch first touches the sheet, and the metal at the contact part yields and deforms preferentially under the action of lateral friction, while other parts at this time Probably not deformed yet. If the hardening index of the material is high, when the metal at the contact part is deformed to a certain extent, the metal at the deformed part will undergo work hardening, making it difficult to continue deformation. At this time, the undeformed metal adjacent to it is easily deformed due to unworked hardening, and yields and deforms under a certain force. After deformation, the metal hardens and continues to deform. Adjacent to the undeformed metal, causing the undeformed metal to continue to deform. Reciprocating in this way, the deformation of the entire plate is relatively uniform. When the hardening index of the sheet metal is low, the preferentially deformed part is not hardened very much, and the deformation always occurs in the preferentially deformed part, which eventually leads to the appearance of cracks and even fractures.

General deep-drawing method such as " the manufacture method of thin-walled deep-drawing container " (CN88103452,) patented technology is very low yield when deep-drawing low plasticity and low hardening index thin plate, easily pulls crack.

Contents of the invention

The invention aims to overcome the defects of the prior art, and aims to provide a deep-drawing method for thin plates with low plasticity and low hardening index with high yield, no cracks, no wrinkling and high production efficiency.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: first place a thin plate with low plasticity and low hardening index and two industrial pure aluminum plates with the same plane size as the thin plate separately in a resistance furnace, heat to 80 ° C ~ T _{for recrystallization} , keep warm for 0.1 to 3 hours.

The drawing mold is preheated 4 to 6 minutes before the thin plate with low plasticity and low hardening index and the industrial pure aluminum plate are released from the furnace, and the surface temperature of the mold is preheated to the temperature when the thin plate and the industrial pure aluminum plate are released from the furnace.

Then the thin plate with low plasticity and low hardening index and the industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, and the thin plate and the two industrial pure aluminum plates are mutually Alignment; put it on the deep drawing die for deep drawing, and the relative movement speed of the punch and die during deep drawing is 0.01～30mm/s.

The low plasticity and low hardening index sheet refers to a metal sheet with an elongation lower than 12% and a hardening index smaller than 1.2.

Due to the adoption of the above technical solution, the present invention controls the drawing temperature within an appropriate range, which solves the problem of drawing low-plastic materials, that is, improves the plasticity of the furnace. Generally speaking, as the temperature rises, since the movement of dislocations is often controlled by the diffusion mechanism, atoms diffuse easily at high temperatures. Therefore, the slip and climb of dislocations are easier, and the plasticity of the material is improved. As the temperature increases, the elongation generally increases. However, if the temperature is too high, the material may recrystallize, reducing the strength of the material and reducing its performance. Therefore, it is very important to control the drawing temperature in an appropriate range.

Therefore, the invention has the characteristics of high yield, no cracks, no wrinkling and high efficiency, and the method is suitable for deep drawing of thin plates with low plasticity and low hardening index.

Specific implementation plan:

The present invention will be further described below in combination with specific embodiments, which are not intended to limit the scope of protection.

In this specific embodiment: the hardening index of the thin plate with low plasticity and low hardening index is less than 1.2; the resistance furnace is a precise temperature-controlled resistance furnace with a thyristor controller. To avoid repetition, details are not repeated in the embodiments.

Example 1

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is an aluminum thin plate of 0.8mm, and the elongation at room temperature is lower than 10%; the deep-drawing is a cylindrical piece.

First place a 0.8mm low plasticity, low hardening index aluminum sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 180-200°C, and keep warm for 0.1-0.15 hours. The drawing mold is preheated 4 to 5 minutes before the low plasticity, low hardening index aluminum sheet and the industrial pure aluminum sheet are released from the furnace, and the surface temperature of the mold is preheated to the temperature when the thin sheet and the industrial pure aluminum sheet are released from the furnace.

Then said 0.8mm low plasticity, low hardening index aluminum thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, the thin plate and two industrial pure aluminum plates The upper and the lower are aligned with each other; put it on the deep drawing die for deep drawing, and the relative moving speed of the punch and the die during the deep drawing is 0.01～.01mm/s.

Example 2

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is an aluminum thin plate of 1mm, and the elongation at room temperature is lower than 9%; the drawing is a hat-shaped piece.

First place a 1mm low-plasticity, low-hardening index aluminum sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 80-100°C, and keep warm for 2-3 hours. 5-6 minutes before the 1mm low plasticity, low hardening index aluminum sheet and industrial pure aluminum sheet are released from the furnace, the drawing mold is preheated, and the surface temperature of the mold is preheated to the temperature when the sheet and industrial pure aluminum sheet are released from the furnace.

Then said 1mm low plasticity, low hardening index aluminum thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, the thin plate and two industrial pure aluminum plates , and bottom are aligned with each other; put it on the drawing die for deep drawing, and the relative moving speed of the punch and the die during the drawing is 0.1~1mm/s.

Example 3

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is an aluminum thin plate of 0.8mm, and the elongation at room temperature is lower than 9%; the drawing is a hat-shaped piece.

First place a 0.8mm low-plasticity, low-hardening index aluminum sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 100-180°C, and keep warm for 1-2 hours. 4 to 5 minutes before the 0.8mm low plasticity, low hardening index aluminum sheet and industrial pure aluminum sheet are released from the furnace, the drawing mold is preheated, and the surface temperature of the mold is preheated to the temperature when the sheet and industrial pure aluminum sheet are released from the furnace .

Then said 0.8mm low plasticity, low hardening index aluminum thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, the thin plate and two industrial pure aluminum plates The upper and lower sides are aligned with each other; put it on the deep drawing die for deep drawing, and the relative movement speed of the punch and die during the deep drawing is 1-5mm/s.

Example 4

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is a 1mm 7075 aluminum thin plate, and the elongation at room temperature is lower than 10%; the deep-drawing is a hat-shaped piece.

First place a 1mm 7075 low-plasticity, low-hardening index aluminum sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 150-200°C, and keep warm for 0.5-1 hour. 4 to 6 minutes before the 7075 low plasticity, low hardening index aluminum sheet and industrial pure aluminum sheet are released from the furnace, the drawing mold is preheated, and the surface temperature of the mold is preheated to the temperature when the sheet and industrial pure aluminum sheet are released from the furnace.

Then said 7075 low plasticity, low hardening index aluminum thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, the thin plate and two industrial pure aluminum plates, Align with each other; put it on the drawing die for deep drawing, and the relative moving speed of the punch and die during drawing is 5-10mm/s.

Example 5

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is a 1mm 7075 aluminum thin plate, and the elongation at room temperature is lower than 12%; the deep-drawing is a hat-shaped piece.

First place a 1mm 7075 low-plasticity, low-hardening index aluminum sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 200 ° C ~ T _{for recrystallization} , and keep warm for 0.15 to 0.5 hours. 4 to 5 minutes before the 7075 low plasticity, low hardening index aluminum sheet and industrial pure aluminum sheet are released from the furnace, the drawing mold is preheated, and the surface temperature of the mold is preheated to the temperature when the sheet and industrial pure aluminum sheet are released from the furnace.

Then said 7075 low plasticity, low hardening index aluminum thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, the thin plate and two industrial pure aluminum plates, Align with each other; put it on the drawing die for deep drawing, and the relative moving speed of the punch and die during drawing is 10-30mm/s.

Example 6

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is a spray-deposition rolled low-carbon steel thin plate of 1mm, and the elongation at room temperature is lower than 12%; the deep-drawing is a hat-shaped piece.

First place a 1mm spray-deposited rolled low-carbon steel sheet and two industrial pure aluminum sheets with the same plane size as the sheet separately in a resistance furnace, heat to 200°C-320°C, and keep warm for 0.5-1 hour. 4 to 5 minutes before the spray-deposited rolled low-carbon steel sheet and the industrial pure aluminum sheet are released from the furnace, the drawing die is preheated, and the surface temperature of the mold is preheated to the temperature when the thin sheet and the industrial pure aluminum sheet are released from the furnace.

Then said spray deposition rolled low-carbon steel thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, and the thin plate and the two industrial pure aluminum plates, the lower Align with each other; put it on the drawing die for deep drawing, and the relative moving speed of the punch and die during drawing is 10-20mm/s.

Example 7

A deep-drawing method for a thin plate with low plasticity and low hardening index: the thin plate with low plasticity and low hardening index is a spray-deposited rolled brass thin plate of 1mm, and the elongation at room temperature is lower than 11%; the deep-drawing is a cylindrical piece.

First place a 1mm spray-deposited and rolled brass sheet and two industrial pure aluminum sheets of the same plane size as the sheet separately in a resistance furnace, heat to 180°C-260°C, and keep warm for 0.5-1 hour. The drawing die is preheated 4 to 5 minutes before the spray deposition rolled brass thin plate and industrial pure aluminum plate come out of the furnace, and the surface temperature of the mold is preheated to the temperature when the thin plate and industrial pure aluminum plate are released from the furnace.

Then said spray-deposited rolled brass thin plate and industrial pure aluminum plate are quickly released to the drawing die, and then the thin plate is sandwiched between two industrial pure aluminum plates, and the thin plate and the two industrial pure aluminum plates are mutually Alignment; put it on the deep drawing die for deep drawing, and the relative movement speed of the punch and die during deep drawing is 5-10mm/s.

This specific embodiment has the characteristics of high yield, no cracks, no wrinkling and high efficiency, and the method is suitable for deep drawing of thin plates with low plasticity and low hardening index.

Claims (2)

1. the method for drawing of an inductile, low hardenability value thin plate is characterized in that earlier inductile, low hardenability value thin plate placed apartly in resistance furnace with two blocks of technical pure aluminium sheets identical with this thin plate planar dimension, is heated to 80 ℃～T _{Crystallization again}, be incubated 0.1～3 hour;

Came out of the stove preceding 4～6 minutes at described inductile, low hardenability value thin plate and technical pure aluminium sheet, cupping tool is carried out preheating, the temperature that mold surface temperature is preheated to this thin plate and technical pure aluminium sheet when coming out of the stove;

The cupping tool of then described inductile, low hardenability value thin plate and technical pure aluminium sheet being come out of the stove rapidly is close to, and this sheet pack is clipped in the middle of two blocks of technical pure aluminium sheets this thin plate and two upper and lower mutual alignment of technical pure aluminium sheet again; Be put into and carry out pull and stretch on the cupping tool, the relative movement speed of punch and die is 0.01～30mm/s during pull and stretch.

2. the method for drawing of inductile according to claim 1, low hardenability value thin plate, it is characterized in that described inductile, low hardenability value thin plate be meant percentage elongation be lower than 12% and hardenability value less than 1.2 sheet metal.