189 2937 2260

Screw production process (1)- annealing

One, purpose: heat the wire to the appropriate temperature, keep a certain time, and then slowly cool down, in order to adjust the crystalline structure, reduce the hardness, improve the wire room temperature processing.

Two, operation process:

(I) Feeding: put the products to be processed into the furnace, pay attention to the furnace cover should be tightly closed. Generally, one furnace can process 7 rolls (about 1.2 tons/roll) at the same time.

(2) Heating up: increase the temperature in the furnace slowly (about 3-4 hours) to the prescribed temperature.

(3) Heat preservation: Material 1018, 1022 wire is kept at 680℃-715℃ for 4-6h, material 10B21, 1039, CH38F wire is kept at 740℃-760℃ for 5.5-7.5h.

(IV) Cooling: reduce the temperature in the furnace slowly (about 3-4 hours) to below 550℃, and then cool down to room temperature with the furnace.

Three, quality control:

1, hardness: material for 1018, 1022 wire annealing hardness of HV120-170, material for carbon wire annealing hardness of HV120-180.

2, appearance: the surface shall not have oxide film and decarbonization phenomenon.

Screw production process (2)- pickling

Objective: To remove the oxide film on the wire surface and form a phosphate film on the metal surface, so as to reduce the abrasion of the die in the process of wire drawing and cold pier or forming.

Two, operation process:

(1) Pickling: the whole disk is immersed in three acid tanks with a concentration of 20% to 25% at room temperature for several minutes, the purpose of which is to remove the oxide film on the surface of the wire.

(2) Clean water: remove hydrochloric acid corrosion products on the surface of wire.

(3) Oxalic acid: to increase the activity of the metal, so that the next process to generate a more compact skin film.

(4), skin film treatment: the disk element immersed in phosphate, iron and steel surface contact with the treatment solution, iron and steel dissolved into insoluble compounds (such as Zn2Fe (Po4) 2? 4H2o), attached to the surface of steel to form a skin film.

(5) Clean water: remove the residue on the surface of the skin film.

(6) lubricant: Because the friction coefficient of phosphate film is not very low, it can not give sufficient lubrication during processing, but it reacts with metal soap (such as sodium soap) to form a hard metal soap layer, which can increase its lubrication performance.

Screw production process (3)- draw line

1. Purpose: Cold pull the disk to the desired wire diameter. In practical terms, it can be divided into two stages of coarse pumping (shell stripping) and fine pumping for some products.

Two, the operation process

After pickling, the disk element is cold drawn to the desired wire diameter through the wire drawing machine. Suitable for large screws, nuts, teeth used wire.

Screw production process (4)- forming

Purpose: The wire is cold-forged (or hot-forged) to achieve the shape and length (or thickness) of the semi-finished product.

Two, operation process:

1, hexagonal bolt (four die four punch or three die three punch)

(1) Cut off: the wire stuck in the cutting die is cut into the required blank material by moving the scissors in one direction.

(2) One punch: the back punching die holds the blank material and squeezes the blank material, and then the blank material is pushed out by the back punching die.

(3) Two punching: the blank material enters the second punching die, the two punching die extrudes, the blank material is oblate, and then the back punching die pushes the blank material out.

(4) Three punching: the embryo material enters the third dozen die, through the hexagonal three punching die kernel shearing, the embryo material hexagonal head is initially formed, after that, the back punching die pushes the embryo material into the third dozen die, the cutting material is cut from the hexagonal head, and the hexagonal head is formed.

2. Hexagonal bolt (three dies and three flushes)

3, screw (general head type one mold two flushes)

(1) Cut off: the wire stuck in the cutting mold is cut into the required blank material by one-way movement of movable scissors.

(2) One punch: the die is fixed, and the head of the product is initially formed by one punch so that the next stroke can be fully formed. When the product is a word cutting groove, a punch die for concave, oval groove, the product is a cross groove, a punch die for concave square groove.

(3) Two strokes: After the first stroke, the punching tool runs as a whole, and the two strokes move to the front of the punching die. At the same time, the two strokes move forward to shape the product. After that, the blank material is pushed out by the back punching rod.

3, hot hit

1. Heating: Heat the forming end of the blank material to the white-hot state in the heating equipment, and set the heating temperature and time according to the product specifications. Generally under 3/4 heat 7-10 seconds, 7/8-1 "heat about 15 seconds.

2, forming: the heated blank material quickly moved to the forming machine, through the back seat, clamping mold fixed, head mold impact blank material, to be formed. The distance of the backseat can be adjusted according to the length of the blank material.

3, bundle rod: in the bundle rod machine using extrusion to reduce the product rod.

Hot beat is also called red beat.