How to make weld caps steel pipe



This specification specifies the technical requirements and operating methods for pressing the compression head. And suitable for the material of carbon steel

Head pressing process code

1. Subject content and scope of application

This specification specifies the technical requirements and operating methods for pressing the compression head. And suitable for the material of carbon steel, low alloy steel

Heating pressing and repairing of edge, flat, elliptic head and disc head arch plate.

2 Reference Standards

GB/T25198-2010 "Steel pressure vessel head"

GB/T25198-2010 "shell type boiler pressure elements manufacturing technical conditions"

3 Technical requirements for operators

3.1 Operators should be familiar with drawings, technical requirements and process specifications.

3.2 Operators should be familiar with the performance, structure and necessary maintenance knowledge of the equipment, molds and tools used

, strictly abide by the operation

Regulations. Operators of heating furnaces and presses are required to hold operating licenses

In order to operate.

3.3 Operators should carefully manage the site

, the workpiece, the mold, the tool should have the corresponding station appliance


Placed in the designated place to prevent damage and corrosion.

4 Equipment and tooling

4.1 The performance of various hydraulic press, heating furnace, feeding trolley and other equipment shall conform to the provisions in the equipment manual. 4.2 Tooling tooling, tools and measuring tools include forming die, composite die, stripping device, support foot, fastening wrench, hand hammer and large

Hammer, pneumatic grinding wheel, wind shovel, steel tape measure, box rule, steel rule, bending rule, caliper, internal and external caliper, thermometer, etc

, the mold should

It can only be used after inspection. Measuring tools and instruments shall be periodically certified as required.

5. Production of blank of head

5.1 Head blank Size (calculation formula) P=1.2(PN+δ+2h)

5.2 When drawing the cutting line, first draw the cross center line, then draw the blank line and the manhole opening line. The length axis of the manhole should be the same as the cross center line

Coincide and the long axis must be perpendicular to the rolling direction of the plate (the rolling direction is usually the length direction of the plate).

5.3 During blanking, the blank outer circle of the head can be cut manually, and it is easy to use centering cutting

, copy cutting is recommended.

5.4 Splicing of blank head

5.4.1 The blank of head shall be made of whole steel plate as far as possible. If splicing is required, two steel plates are allowed according to GB/T25198-2010

Standard and GB/T25198-2010 standard, construction drawing.

5.4.2 After welding, inner surface splicing welds and outer surface splicing welds that affect forming quality

, the weld should be finished before forming

High grinding to flush with the base material, the leveling length is 300 ~ 350mm from the outer edge of the round billet.

Code: JYL Technology -01/11

Edition: A Modified: 1

Page number: 25/40

5.6 When pressing the perforated head, the small hole in the middle should be smooth and flat, and the sawtooth edge of the gas cutting should be polished and smooth, so as not to

Cracking occurs when pressing holes and flanging.

5.7 Blank must be transplanted with material marking according to < Regulations >

, the label must be clear and correct.

6 Technical Requirements for billet heating 6.1 Preparation before heating

6.1.1 Obstacles around the heating furnace must be removed

The sundries in the heating furnace should be removed, and the sundries on the billet should be put before loading the furnace

Clean it up.

6.1.2 Check the feeding tools to ensure normal operation and safe loading.

6.1.3 The diameter, thickness and material of the blank must be checked clearly with the drawing

And keep temperature records.

6.1.4 When loading, it shall ensure that the mark of material transplantation is on the lower surface of the blank

To be exposed to the outer surface after stamping.

6.2 Blank heating. See Table 11-1 for the heating specifications.

Table 11-1

Note: Normalizing treatment is generally not required after stamping. If necessary, the treatment temperature shall be specified by the heat treatment process card.

6.3 Precautions for Heating:

6.3.1 The billet shall be put into the furnace at a temperature less than

It is carried out at 600℃, and then heated with the furnace. After reaching the heating temperature, the holding time is about

The value is 1 minute /mm.

6.3.2 Several billets are allowed to be heated at the same time, but attention must be paid to the distance between billets and the distance between billets on the bottom and the bottom of the furnace when loading the furnace

It should not be smaller than 150mm.

Grade of steel

Heating temperature, ℃

Final pressure temperature, ℃

Stamping normalizing treatment temperature, ℃

Q245R, Q345R

P 1050

P 850

6.3.3 When several steel plates are heated together, the amount of one addition should not be too much

Should be pressed for half an hour continuously.

When one piece is taken out, the rest of the billet will continue to be heated in the furnace, and the same stack of steel plates will be taken out one by one. It is not allowed to be taken out before

Cold billet is added to avoid overburning of part of the billet.

6.3.4 In case of press failure, only the failure can be removed in a very short time

Is allowed to put the furnace already in the furnace

Feeding furnace. But the furnace temperature should be reduced to a lower level

600 ~ 700 ℃ to prevent oxidation.

6.3.5 After the billet is insulated according to the specified time, it can be taken out and sent into the lower die by tools (feeding trolley, forklift).

7. Technical requirements for head stamping

Code: JYL Technology -01/11

Edition: A Modified: 1

Page number: 26/40

7.1 Preparations for Stamping

7.1.1 Before stamping, the test car should take several minutes to confirm that the equipment is in good condition for stamping.

7.1.2 Select the mold correctly according to the process rules and avoid using it incorrectly. The thickness of the blank is measured

, check whether the mold specification is appropriate (anti

Stop die swelling and cracking), after the inspection personnel inspection can be used.

7.1.3 After the lower die on the head is installed on the oil press, check the position of the upper and lower die. The clearance of the upper and lower die should be uniform.

Nuts and other fasteners should be tightened to ensure safety.

7.1.4 Lubricant should be coated on the die before stamping. lubricant

40% graphite powder and 60% oil, or graphite

Powder mixed with water.

7.2 Head stamping

7.2.1 Before or during the stamping of the head, when the working face of the holder ring is found to be pulled, it shall be smoothed in time. 7.2.2 Range of blank holder rings:

(1) Oval head: mild steel

D0/S≥85; Low alloy steel D 0/S≥80.

(2) Flat head :D0/S≥16.

7.2.3 The gap between blank and blank holder should be as small as possible to ensure no bulge.

7.2.4 When pressing the flat head (tube plate), after the upper die passes through the lower die ring, it can continue to the working platform of the press to ensure sealing

Level the head plane once.

7.2.5 After demoulding, the head and tube plate are not allowed to contact the upper die again or be pressed twice

, to prevent oversize.

7.2.6 The flat head after stamping shall be cooled to

After 550℃, it can be carefully removed from under the lower die and lifted away to prevent deformation

Do not bump and scratch, for large size head, measures should be taken to prevent lifting deformation.

7.2.7 After the head is removed from the press, it shall not be placed at the air outlet. In particular, the flat head shall be placed flat to prevent the cooling rate from falling

Consistent, produce deformation warping.

7.2.8 Batch pressing can be carried out only after the first part has passed the inspection.

7.2.9 After pressing 10 ~ 15 heads continuously, the dimensions of the workpiece should be measured to avoid overheating of the mold

Geometric size increases.

When the workpiece size is too large due to the overheating of the mold

To take appropriate cooling measures to the mold, with a thermometer to measure the mold

The temperature must not exceed 250 ℃.

In the process of stamping the die, lubricant should be added timely. When installing mold with perforated head and flanged flat tube plate,

Attention should be paid to manhole flanging punch and die manhole flanging hole (punch and upper die)

The gap between them is uniform.8, head spinning:

Code: JYL Technology -01/11

Edition: A Modified: 1

Page number: 27/40

8.1 Head spinning:

8.1.1 Cold spinning of head is a feasible and reasonable new manufacturing process of head. In order to ensure the quality of cold spinning head, especially

Formulate this process code.

8.1.2 This Code follows the relevant provisions of GB150-2011 and GB/T25198-2010.

8.1.3 This code shall be used together with relevant product drawings, technical conditions, process rules and safety operation rules for spinning machines.

8.2 Preparations Before spinning

8.2.1 Check whether the billet material, mark and billet specification are consistent with the "Process Flow Inspection card".

8.2.2 The billet weld and edge shall be strictly polished and flush with the base material.

8.2.3 Select the mold correctly according to the process rules. Flanging machine to adjust the pressure wheel track curve and the corresponding forming wheel

Be consistent with.

8.2.4 Before spinning, test the machine for a few minutes to confirm that the mechanical, cold pressing system and electrical system are in good condition for spinning.

8.3. Press the drum

8.3.1 The compaction force should be as small as possible for a material of given thickness to avoid thinning of billet thickness and causing cracks. build

The pressure and drum force should be controlled at 5-15Mpa, and the maximum should not exceed 20Mpa

8.3.2 The depth of the press drum should be ensured. It should not be shallow or too deep. In addition, pay attention to the smooth surface, and finally use the sample

Board strict acceptance. 8.4 Flanging

8.4.1 Control the arc starting point and flanging amount, so as to know well before flanging.

8.4.2 Flanging return time according to the proficiency of flexible grasp, not in a hurry, and not too long, to be bold and careful.

8.4.3 If cracks occur on the edge of the head during flanging, the machine should be shut down for repair. If you continue flanging the head will produce a wrong edge.

8.4.4 Strictly measure the perimeter and control the range of positive and negative deviations.

8.5 Heat Treatment

8.5.1 In addition to stainless steel, cold forming head should be heat-treated after forming, generally

20g, 16MnR materials should be pressed into

Annealing in the middle of row. If the user has special requirements, the relevant heat treatment should also be carried out.

8.5.2 Annealing temperature is recommended to be 620-650, hold for 1-2 hours, furnace cooling to 300-400℃ after air cooling, straight is not allowed

Connect to air cooling.

8.6 Inspection

According to the relevant technical standards, the shape of the forming head of the geometric size, shape deviation, thickness reduction and other items.

9. Inspection and repair

9.1 The quality inspection of the head mainly checks the surface condition, geometry and size of the head. For a few fine cracks, people

The cylindrical part of the hole pulling edge is greater than the starting point of the circular arc of the pulling edge

The 5mm tear can be carried out after the approval of the technical inspection department

After grinding and repairing welding, the thickness of the steel plate after grinding should still be within the standard allowable deviation range.

After repairing welding, the surface is qualified by non-destructive inspection.

Before you can move on to the next process.

Code: JYL Technology -01/11

Edition: A Modified: 1

Page number: 28/40

9.2 For raised and sunken scars, when the depth does not exceed 10% of the plate thickness and the maximum does not exceed 1mm, it can be polished and smooth transition; When the depth exceeds, it should be repaired and polished, and the treatment after repair welding should be the same


9.3 After pressing the thin plate head (D0/S ≥ 150), some bulge can be cold repaired or partially heated hammer corrected; When head

The roundness is out of tolerance, can be checked by the foreign template, with hammer correction, but hammer correction can not directly hammer the workpiece, must use a flat hammer

Or iron pad or wood hammer correction, there are individual hammer marks should be polished.

9.4 Non-destructive inspection shall be conducted after surface defect repair welding.

9.5 The geometric shape and size deviation of the head shall be consistent

GB/T25198-2010, GB/150-2011 requirements and products

As required in the production drawing.

10.0 Universal cone manufacturing process

Scope of application; This standard is made

CHA cone heads make provisions that require negotiation for individual cases.

This process refers to the standard GB/T25198-2010;

Vertebrae are divided into CHA (30°) CHA (45°) CHA (60°) according to different pinch angles

10.1. Cutting and marking of cone;

10.1.1 Cone flapping principle;

a, minimize the number of splits, the number of heads.

b, considering the size of conventional plate rolling, as well as transportation conditions, as far as possible do not use customized plate.

c. Consider the height of the upper die

10.1.2 Calculation of the original blank. 1.R=d/2sin a/2 2 .d?

? = 2? Rβ/360 can be obtained from Equation 1.2. β =360sin a/2

Calculate the R and β values after the four weeks of processing allowance, with computer typesetting to determine the size and quantity of all steel plates.

Large mouth and small mouth with twice the plate thickness of the margin, plate thickness is greater than

The allowance of 50mm is 50mm, female

Line direction with 1.5 times -2 times the thickness of the plate as a margin. The adjustment method of the coefficient is to increase with the plate thickness.

10.1.3: Lofting and cutting

a: The template is made. The marking template is made in the form of a whole single piece, based on the endothelium, and the error of each size is not less than

1mm, sample

The board is made of thin iron sheet and linoleum paper.

b: Underline

Before marking, check whether the material, size and standard are in conformity, and confirm the reinspection is qualified, and draw the cutting line and cone flap

Endothelial development dimension line. After marking, check arc length, diagonal and bus length, and punch hole cutting.

10.2. Mold preparation and equipment selection

Code: JYL Technology -01/11

Edition: A Modified: 1

Page number: 29/40

10.2.1 The diameter of upper die is generally 50mm-80mm bar material with R arc, and the length is generally 1000mm-3000mm

The bar material of

10.2.2 Two rods with a diameter of 50mm-80mm and a length of 1500mm-3000mm are used for the lower mold. They are placed in figure-eight shapes for the lower mold

The Angle is adjusted according to the size parameters of the cone and the ability of the equipment to allow pressing.

10.2. 3. Select different pressing mechanisms according to plate thickness and cone size

10.3.1 Making Preparations,

a. Confirm the drawings, clarify the production tasks of this process, carefully read the drawings, read the technical requirements, and timely report to the workers if there is any question

The artist communicates.

b, large cone super plate thick and segmented and thin-walled vertebral body is different, thick plate cone to do three-dimensional template, sample

The arc length of a plate is not less than the arc length of a single piece

1/3, the sample adopts the size of the mouth in one piece, convenient in the pressing process

The dimensions of the diagonal in

10.3.3 Pressing method, adopt cold spot pressing forming, alternately pressing from both ends to the center, pressing force must be uniform,

In the process of pressing

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