Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the preparation method of the beryllium copper ring forging, which can reduce the crack tendency of the beryllium copper ring, improve the product performance, the quality and the production efficiency, and reduce the cost and the rejection rate.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a preparation method of a beryllium copper ring forging comprises the following steps:
(1) blanking: selecting a beryllium copper ingot to be blanked according to the size of a beryllium copper ring product, and chamfering R5mm at two end faces of the blanked blank;
(2) heating before forging: charging the beryllium copper ingot obtained by blanking into a furnace, wherein the temperature in the furnace is less than or equal to 50 ℃, laying heat preservation cotton on the bottom of the electric furnace in advance, then filling the ingot, placing the ingot on the heat preservation cotton, and forbidding the ingot to be in direct contact with a bottom iron pad; after the charging is finished, the temperature in the furnace is raised to 600 ℃ at the speed of 100 ℃/h, and then the temperature is kept for 2 h; then raising the temperature to 780-790 ℃ at the speed of 100 ℃/h, preserving the heat for 12h, and then discharging the product from the furnace for forging; baking the upper and lower flat anvils and clamping the jaws to 300 ℃;
(3) forging: upsetting the heated beryllium copper cast ingot, drawing out after upsetting, and upsetting for the second time after drawing out;
(4) punching: the beryllium copper blank after the secondary upsetting is put into a furnace and heated, the temperature is raised to 780-790 ℃, the heat is preserved for 6 hours, and the beryllium copper blank is taken out of the furnace and sequentially subjected to hexagonal pressing, chamfering, upper and lower end face flattening, rounding, end face flattening, punching and trestle reaming;
(5) ring rolling: heating the blank with the hole expanded in the trestle in a furnace to 770-780 ℃, and preserving heat for 4.5 h; preheating a core roller, a main roller, a guide roller and a conical roller of a ring rolling machine in advance until the local appearance is dark red, and rolling the ring until the size of a beryllium copper ring forging blank is reached;
(6) solid solution: charging the beryllium copper ring forging blank at room temperature, heating the blank to 780-790 ℃ at the speed of less than or equal to 100 ℃/h, preserving heat for 4h, then rapidly cooling by water, wherein the water temperature is less than 25 ℃, and cooling until the surface temperature of the beryllium copper ring forging blank reaches the room temperature;
(7) aging heat treatment: and (3) firstly processing the beryllium copper ring forging blank after the solution treatment, carrying out aging treatment after the blank is processed to the drawing size, keeping the temperature at 180-220 ℃ and 300-320 ℃ for 2h respectively, and then discharging from the furnace and carrying out air cooling to room temperature to obtain the finished product of the beryllium copper ring forging.
Furthermore, the Be content of the beryllium copper ingot in the step (1) is below 2.2%.
Further, the heating time before the trestle broaching forging is as follows: t = b × (1.5 to 2.0); wherein t is heating time, unit: min; b is wall thickness, unit: mm.
Further, the height and the diameter of the upset are controlled according to preset values:
(ii) a Wherein, H is the forging stock height, and d is the forging stock diameter, the unit: mm.
Further, the forging deformation amount in the step (4) is required to be: the first fire time and the last fire time are less than or equal to 30mm in pressure drop, and the middle fire time is less than or equal to 50mm in pressure drop.
Further, the punching diameter control in the step (4) is controlled according to preset values as follows:
and D is the outer diameter of the beryllium copper blank after the secondary upsetting, and the unit is as follows: mm.
Further, the ring rolling machine in the step (5) adopts a RAM3500 ring rolling machine.
Further, the ring rolling mill in the step (5) is preset with target size phi 850mm phi 710mm phi 135mm, and density setting: 8.25kg/dm3The linear expansion coefficient is 18 per mill.
Has the advantages that: according to the size requirement of the beryllium copper ring piece, selecting a corresponding beryllium copper ingot, heating the ingot to a preset temperature for upsetting, drawing out and secondary upsetting, punching, trestle reaming and ring rolling to obtain a beryllium copper ring forging blank, and performing solution treatment, processing and aging treatment to obtain a final beryllium copper ring forging finished product. The preset value of the heating time before forging is controlled in the same mode in the forging process, the relation between the drawing height and the upsetting diameter is controlled in the same mode according to the preset value, and the reaming diameter of the trestle is controlled according to the upsetting section in the preset value. According to the invention, by controlling the heating time of the beryllium-copper alloy before forging and the height of the ring piece, the height and the deformation of the ring blank are effectively controlled, the cracking problem caused by unreasonable control of the heating degree and the size is reduced, the product performance is more stable and excellent, the production cost is reduced, and the product percent of pass is improved.
Detailed Description
The invention is illustrated below with reference to specific examples. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.
Referring to fig. 1 and fig. 2, according to the difference in the thickness of the beryllium-copper forging, different preset heating time values are set in the trestle reaming link before forging:
t = b × (1.5 to 2.0) formula (1),
wherein t is heating time, unit: min; b is wall thickness, unit: mm.
Setting the relation between the upsetting height and the diameter according to the height of the beryllium copper piece forge piece:
the compound of the formula (2),
wherein H is the height of the beryllium copper forging stock, d is the diameter of the beryllium copper forging stock, and the unit is as follows: mm.
In a trestle reaming link, according to the section size of a beryllium copper piece, controlling the diameter of a punched hole by adopting a preset value:
the compound of the formula (3),
wherein, H is the beryllium copper forging stock height, and D is beryllium copper forging stock diameter, unit: mm.
And in the ring rolling section, the size of the ring rolling is controlled to be +20 mm.
Therefore, the reaming size of the metal piece trestle with the preset value is obtained, the sizes of the inner hole and the outer hole required by the forge piece can be obtained after reaming, and the forging size requirement is met.
Example 1
A preparation method of a beryllium copper ring forging comprises the following steps: the size of the forging is as follows: Φ 1980 mm. times.Φ 1915 mm. times.380 mm. The method comprises the steps of blanking, heating before forging, punching, ring rolling, solid solution and aging heat treatment, and comprises the following specific steps:
(1) blanking: selecting a beryllium copper ingot with phi 480mm multiplied by 1120mm according to the size of a product, wherein the Be content of the beryllium copper ingot is below 2.2%, blanking the beryllium copper ingot, sawing the head part by 70mm, and sawing the tail part by 20 mm;
(2) heating before forging: charging the discharged beryllium copper ingot at room temperature, wherein the furnace temperature is less than or equal to 50 ℃, paving heat preservation cotton at the bottom of the electric furnace in advance, then loading the ingot into the furnace, placing the ingot on the heat preservation cotton, and forbidding the ingot to be in direct contact with a bottom iron pad; raising the furnace temperature to 600 ℃ at the speed of 100 ℃/h, preserving the heat for 2h, then heating to 780 ℃ at the speed of 100 ℃/h, preserving the heat for 12h, and discharging; baking the upper and lower flat anvils and the jaw to 300 ℃;
(3) forging: upsetting the heated beryllium copper cast ingot, drawing out after upsetting, and upsetting for the second time after drawing out; as can be seen from the formula (2), the bottom surface diameter Φ =600mm when the height H =650mm is upset; the height of the screw is 30mm, 40mm and 40mm in sequence;
(4) punching: the beryllium copper blank after the secondary upsetting is charged into a furnace and heated, the temperature is raised to 780 ℃, the blank is kept for 6 hours and taken out of the furnace, hexagonal shape, chamfering, upper and lower end surfaces are flattened, rounding and end surface flattening are carried out in sequence, then punching is carried out, the punching diameter phi is 200 plus 300 mm, and the punching diameter is 280mm according to the field condition; reaming to H =470mm, D =800mm and D =1050mm by using a mandrel saddle with the specification of phi 280 mm;
(5) ring rolling: after reaming the trestle, the blank is put into a furnace and heated to 770-780 ℃, and heat preservation is carried out for 4.5 h; preheating a core roller of a ring rolling mill, a main roller, a guide roller and a conical roller until the local appearance is dark red, and rolling the ring until the size of a forged piece is phi 2020mm multiplied by phi 1890mm multiplied by 430 mm;
(6) solid solution: charging the beryllium copper ring forging blank at room temperature, heating the blank to 780 ℃ at the speed of less than or equal to 100 ℃/h, preserving heat for 4h, rapidly cooling by water, cooling the water to 23 ℃, cooling to the surface temperature of 22 ℃ of the beryllium copper ring forging blank, and finishing solid solution and water cooling;
(7) aging heat treatment: the beryllium copper ring forging blank after the solution treatment is firstly processed to phi 1980mm multiplied by phi 1915mm multiplied by 380mm, and then is aged, and the charging temperature is 45 ℃. Keeping the temperature at 200 ℃ and 320 ℃ for 2h respectively, discharging the alloy from the furnace, and cooling the alloy to room temperature in the air to obtain a beryllium copper ring forging finished product.
And (3) performing performance test on the beryllium copper ring forging, wherein the grain size is 6 grade, the conductivity of the body is 28.5 IACS, and the standard requirements are met.
Example 2
A preparation method of a beryllium copper ring forging comprises the following steps: the size of the forging is as follows: phi 1600mm x phi 1540mm x 380 mm. The method comprises the steps of blanking, heating before forging, punching, ring rolling, solid solution and aging heat treatment, and comprises the following specific steps:
(1) blanking: beryllium copper cast ingots with the diameter of phi 750mm multiplied by 920mm are selected to be blanked according to the size of the product, the head part is sawed for 70mm, and the tail part is sawed for 20 mm;
(2) heating before forging: charging the beryllium copper ingot obtained by blanking at room temperature, wherein the temperature in the charging furnace is less than or equal to 50 ℃, paving heat preservation cotton on the bottom of the electric furnace in advance, then loading the ingot, placing the ingot on the heat preservation cotton, and forbidding the ingot to be in direct contact with a bottom iron pad; raising the furnace temperature to 600 ℃ at the speed of 100 ℃/h, preserving the heat for 2h, then heating to 780 ℃ at the speed of 100 ℃/h, preserving the heat for 12h, and discharging;
(3) forging: upsetting the heated cast ingot, drawing out after upsetting, and performing secondary upsetting after drawing out; as can be seen from the formula (2), the bottom surface diameter Φ =680mm when the height was increased to H =515 mm; the height of the screw is 30mm, 20mm and 10mm respectively;
(4) punching: the beryllium copper blank after the secondary upsetting is charged into a furnace and heated, the temperature is raised to 780 ℃, the heat is preserved for 6H, the blank is discharged from the furnace, hexagonal shape, chamfering, upper and lower end surfaces are flattened, rounding and end surface flattening are sequentially carried out, then punching is carried out, according to the formula (3), the punching diameter phi 260 plus material 340mm is obtained, a phi 280mm punch is used for punching, and then a saddle hole with the specification of phi 280mm is used for reaming H =490mm, D =850mm and D =1100 mm;
(5) ring rolling: after reaming the trestle, putting the blank into a furnace, heating to 780 ℃, and preserving heat for 4.5 hours; preheating a core roller of a ring rolling mill, a main roller, a guide roller and a conical roller until the local appearance is dark red, and rolling the ring until the size of a forged piece is phi 1620mm multiplied by phi 1485mm multiplied by 470 mm;
(6) solid solution: charging the beryllium copper ring forging blank at room temperature, heating the blank to 780 ℃ at the speed of less than or equal to 100 ℃/h, preserving heat for 4h, rapidly cooling by water, cooling the water to 25 ℃, and cooling to the surface temperature of 23 ℃ of the beryllium copper ring forging blank to finish solid solution and water cooling;
(7) aging heat treatment: the beryllium copper ring forging blank after the solution treatment is firstly processed to phi 1600mm multiplied by phi 1540mm multiplied by 380mm and then subjected to aging treatment, and the charging temperature is 48 ℃. Keeping the temperature at 200 ℃ and 320 ℃ for 2h respectively, discharging the alloy from the furnace, and cooling the alloy to room temperature in the air to obtain a beryllium copper ring forging finished product.
And (3) performing performance test on the beryllium copper ring forging, wherein the grain size is 6 grade, and the conductivity of the body is 28 IACS, and the beryllium copper ring forging meets the standard requirement.