Manufacturing technology of OGV-G-25-1.0-3 tank.

Contents

Contents

Paper

Introduction

1TECHNOLOGICAL SECTION

1.1. Main characteristics of the article

1.2. General requirements for the design of pressure receptacles

1.3. Requirements for welds

1.4. Basic Material Requirements

1.4.1. Steel sheet

1.5. Welding

1.5.1. Requirements for welded joints

1.5.2. Selecting Welding Methods

1.6. Heat treatment of welded elements of vessels

1.7. Process Design

1.8. Procurement activities

1.9. Main material weldability analysis

1.10. Selecting Welding Materials

1.11. Selecting Welding Modes

1.11.1 Calculation of modes for automatic welding under flux layer

1.11.2 Modes for mechanized welding in the environment of protective gases

1.12. Selection of welding equipment

1.12.1. Equipment for mechanized welding in carbon dioxide environment

1.12.2. Welding equipment for automatic welding under flux layer

1.13. Assembly Time Standards

1.14. Welding Time Standards

1.15. Calculation of load factor of workplaces and equipment

1.16. Calculation of welding materials expenses

1.17 NDT and fabrication tests

2 DESIGN SECTION

2.1 Selection of process equipment

2.2 Calculation of roller support reduction gear box

3 ORGANIZATIONAL AND ECONOMIC SECTION

3.1 Calculation of process and total cost of the article according to the basic and designed versions 83 3.2 Calculation of the article price according to the basic and designed version

3.3 Calculation of capital investments related to implementation of new welding process

3.4 Calculation of indicators of economic effect and efficiency of welding technology replacement project

3.5 Summary technical and economic indicators of the project

4. WELDING SAFETY

4.1 Analysis of hazardous and hazardous production factors

4.1.1 Infrared and ultraviolet radiation

4.1.2 Noise and vibration

4.1.3 Electrical Safety

4.1.4 Production room air environment and microclimate

4.2 Calculation of ventilation of assembly and welding shop

CONCLUSION

LIST OF SOURCES OF LITERATURE USED

APPLICATION

Paper

The scope of the diploma project: pages - 110; Figures - 7; tables - 30;

drawings and posters - 8

Keywords: AUTOMATIC WELDING UNDER FLUX LAYER, WELDING MODES, APPARATUS, MANUFACTURING TECHNOLOGY, SHELL, WELDING EQUIPMENT

The object of development is the technology of manufacturing a capacitive cylindrical apparatus for liquid and gas non-aggressive media OGVG -25-1.0-3 material version of Type 3 with saddle metal supports according to OST 262091 without heat insulation.

The purpose of the development: Selection of the technology of welding the shell of the apparatus, selection of technological equipment, determination of the cost-effectiveness of the selected solutions.

In order to solve this problem, the design analysis was carried out, the welding methods were analyzed and selected, the strength of the main welds and design elements of the vessel was calculated, the design of the bench for welding was selected, the welding operations were rationed, the economic calculation of the welding technologies used was carried out, the safety of welding processes was considered .

The following results were obtained: The technology of automatic welding under flux was developed when manufacturing the OGVG251.03 tank. Welding equipment and process tooling have been selected. Estimate of economic indicators: the reduction in cost is 1539 rubles. per product, which gives an annual saving of 230850 rubles. Additional investments 57145 rubles. will pay off in 0.24 years.

Summary

In the diploma project on the topic: "Container manufacturing technology

OGV-G-25-1.03 "deals with the technology of assembly, welding and calculation of capacity for strength.

The diploma project contains 110 sheets of explanatory note, 8 drawings, 27 tables, 7 figures.

The project presents solutions to the process of welding of the product, presents calculations of the process modes of mechanized and automated welding, selects welding equipment, presents modern methods for calculating the strength of both the capacity and its individual components.

The technology developed in the diploma project allows to provide the following technical and economic indicators:

- stability of production;

- quality of welds;

- Reduction of material costs.

As a result, economic efficiency is 230,850 rubles/year.

Introduction

In 1802, the Russian physicist Vasily Vladimirovich Petrov discovered the phenomenon of an electric arc and suggested its use for melting metals. The Russian inventor Nikolai Nikolaevich Benardos patented the electric arc welding process in 1886, and since then electric arc welding has become one of the most popular technological processes in all industries.

The essence of the welding method proposed by N.N. Benardos was that the coal rod was attached to one pole of the battery, and a welded article was attached to the other pole. When the carbon rod was brought to the article in the air gap, an electric arc arose that melted the welded edges and the additive metal. So a weld was formed.

The idea of ​ ​ using a melting electrode (a metal rod with a special coating) in electric arc welding belongs to the outstanding Russian engineer N.G. Slavyanov (1888). Technological processes for electric arc welding, developed by N.G. Slavyanov, have not lost their relevance at present.

In the early 20s. the welding process was already mechanized and automated. A significant contribution to the development of electric arc welding was made by the process of automatic welding under the flux layer, developed under the leadership of E.O. Paton in the late 30s.

In the late 40s, a method of arc welding in protective gases was proposed.

An outstanding achievement of welding technology was the development at the IES named after E.O. Paton in collaboration with a number of industrial enterprises in 1949 of electric slag welding, which made it possible to use electric arc welding for large-sized products.

Currently, all welding processes are classified by the types of energy used and are divided into three classes in accordance with GOST 1952174: thermal, thermomechanical and mechanical. Electric arc welding belongs to thermal class.

Currently, new concentrated heat sources have appeared:

- electron flow in vacuum, on the basis of which at the end of the 50s. the electron-beam welding process appeared;

- laser beam, which currently belongs to light sources and is classified as a light beam welding process.

A great contribution to the development of the scientific foundations of melting welding technology was made by Soviet, Russian, Ukrainian scientists of the International Institute of Electric Welding named after E.O. Paton, MSTU (MVTU) named after N.N. Bauman, IMET named after A.A. Baykova, USTU (UPI), Leningrad School welders.

In the modern conditions of industrial production of large-sized welded products, body products occupy a large place, including the bodies of the so-called pressure vessels, which are used in the boiler room, oil and gas production, oil refining and chemical industries. Most of the vessels are process devices that provide technological processes (separation, separation of liquids, mass exchange, heat exchange, etc.).

The purpose of this diploma project is to develop the process of assembly-welding of the housing of the OGVG-25-1.03 apparatus, used to clean gas from related impurities (liquid and gas). It is planned to develop procurement and assembly and welding operations, the choice of welding methods, welding materials, welding and auxiliary equipment and welding inspection methods.

Process Section

1.3. Requirements for welds

Butt joints with full penetration shall be used when welding shells and pipes, welding bottoms to shells.

Welded joints are allowed in tavr and angular with full penetration for welding of flat bottoms, flat flanges, pipe grids, connectors, hatches, jackets.

The use of overlapping welds is allowed for welding to the body of reinforcing rings, support elements, backing sheets, plates for platforms, stairs, brackets, etc.

Structural clearance in angular and T-joints is allowed in cases provided for by LP, agreed in accordance with the established procedure.

Welds shall be available for inspection during the manufacture, installation and operation of vessels as required by the Regulations, relevant standards and specifications.

Longitudinal seams of adjacent shells and seams of vessel bottoms shall be displaced relative to each other by three times thickness of thickest element, but not less than 100 mm between axes of seams.

These seams may not be displaced relative to each other in vessels intended for operation under pressure of not more than 1.6 MPa (16 kgf/cm2) and wall temperature not more than 400 ° C, with nominal wall thickness not more than 30 mm, provided that these seams are performed by automatic or electroslag welding and the places of intersection of the seams are controlled by radiography or ultrasonic flaw detection in the amount of 100%.

When welding internal and external devices (support elements, plates, jackets, partitions, etc.) to the vessel body, it is allowed to intersect these welds with the butt joints of the body, provided that the blocked section of the body seam is checked by radiographic inspection or ultrasonic inspection.

In case of welding of supports or other elements to the vessel body, the distance between the edge of the vessel weld and the edge of the element weld shall be not less than the wall thickness of the vessel body, but not less than 20 mm.

For vessels of carbonaceous and low alloyed manganese and manganese-silicon steels (Annex 3) subjected to heat treatment after welding, regardless of the thickness of the body wall, the distance between the weld edge of the vessel and the weld edge of the element shall be at least 20 mm.

In horizontal receptacles local overlapping of ring (transverse) welds with saddle supports on the total length of not more than 0.35 is allowed, and if there is a lining sheet - not more than 0.5, where - the outer diameter of the receptacle. At the same time, overlapped sections of welds along the entire length should be checked by radiography or ultrasonic inspection. Overlapping of joint crossing points is not allowed.

In butt welded joints of vessel elements with different wall thicknesses, a smooth transition from one element to another must be ensured by gradually thinning the edge of the thicker element. The angle of inclination of the transition surfaces shall not exceed 20 °.

If the difference in thickness of the elements to be connected is not more than 30% of the thickness of the thin element and not more than 5 mm, welds may be used without prior thinning of the thick element. The shape of the seams should ensure a smooth transition from a thick element to a thin one.

When connecting a cast part to parts made of pipes, rolled stock or forgings, it should be taken into account that the nominal design thickness of the cast part is 2540% more than the similar design wall thickness of the element made of pipes, rolled stock or forgings, so the transition from a thick element to a thin one must be made so that the thickness of the end of the cast part is not less than the design value.

1.5. Welding. 

All types of electric arc welding, except gas welding, can be used to weld vessel housings depending on the design and size. Gas welding can only be used for coil pipes.

When welding vessels (assembly units, parts), it is necessary to comply with the requirements of the technical specifications for manufacture, as well as developed and certified technological documentation.

The process documentation shall contain instructions on:

- the use of welding methods for materials selected for the manufacture of vessels (assembly units, parts);

- application of additive materials for welding;

- application of welding equipment;

- welding modes;

- types and scope of welding joints inspection;

- preheating and associated heating;

- heat treatment.

All welding operations during the manufacture of vessels (assemblies and parts) to prevent the occurrence of cold cracks should be carried out at positive temperatures in closed heated rooms. If work is to be done in an open area, the welder and welding site shall be protected against direct rain, wind and snow. Ambient air temperature shall not be lower than 100С

When preparing the edges of welded articles for welding, it is necessary to comply with the requirements of the relevant standards for the welding method and regulatory and technical documentation. Edges prepared for welding shall be cleaned by a width of at least 20 mm. Edges shall have no traces of rust, scale, oil and other contaminants. If it is necessary to clean oil and paint traces, use solvents (gasoline, acetone). Visual inspection of prepared edges shall be performed to detect metal defects. Stratification, sunset, cracks are not allowed.

If impermissible defects are detected, corrections shall be made in accordance with the requirements of the regulatory and technical documentation .

In order to be able to determine the welder who has welded, all welds shall be branded. The mark is applied at a distance of 2050 mm from the weld edge on the outside. If the seam from the outside and inside is brewed by different welders, the marks are placed only from the outside through a fraction: in the numerator the welder's mark from the outside of the seam, in the denominator - from the inside. If the welded joints of the vessel are made by one welder, it is allowed to mark near the plate or in another open area. For longitudinal seams, the mark shall be at the beginning and end of the seam at a distance of 100 mm from the annular seam. On a shell with a longitudinal seam less than 400 mm long, it is allowed to put one stamp. For a ring seam, the stitch must be knocked out at the intersection of the ring seam with the longitudinal seam and then every 2 m, but there must be at least two stitches on each seam. On the annular seam of the vessel with a diameter of not more than 700 mm, it is allowed to put one stamp. Branding of longitudinal and annular seams of vessels with wall thickness less than 4 mm is allowed by electrograph or indelible paint.

The place of marking lies in a clearly visible frame made with indelible paint.

Instead of stitching welds, it is allowed to attach to the vessel passport a scheme of the stitches with the names of welders with their painting.

Before starting welding, the quality of the assembly of the elements to be joined must be checked, as well as the condition of the edges to be joined and the surfaces adjacent to them. During assembly, the edges cannot be fitted by impact or local heating.

Elimination of defects in welds shall be performed in accordance with the instruction or standard of the enterprise for welding of the vessel (assembly unit and part) from this steel grade.

1.5.1. Requirements for welded joints.

When welding shells and pipes, welding bottoms to shells, butt joints with full penetration should be used.

It is allowed to use corner and T-joints when welding connectors, hatches, pipes, pipe grids, flat bottoms and flanges.

It is allowed to use overlapping welds for welding of reinforcing rings and support elements.

Use of corner and T-joints for welding of connectors, panels, bosses and other parts to the housing with incomplete penetration (structural clearance) is not permitted:

- in vessels of groups 1, 2, 3 with hole diameter more than 120 mm, in vessels of groups 4 and 5a with hole diameter more than 275 mm;

- in vessels 1, 2, 3, 4 and 5a of groups of low-alloyed manganese and manganese-silicon steels with wall temperature below 30 ° C without heat treatment and below 40 ° C with heat treatment;

- in vessels of all groups intended for operation in environments causing corrosion cracking, regardless of the diameter of the nozzle, except when a hole is drilled in the areas of the structural gap.

It is not allowed to use structural clearance in connections of flanges with nozzles of vessels operating under pressure more than 2.5 MPa (25 kgf/cm) and at temperature more than 300 ° С, and flanges with shells and bottoms of vessels operating under pressure more than 1.6 MPa (16 kgf/cm) and at temperature more than 300 ° С. No structural clearance shall be allowed in these welded joints regardless of the operating parameters in vessels designed to operate in corrosive cracking environments.

Welded seams of vessels should be arranged so that they can be visually inspected and quality checked using a non-destructive method (ultrasonic, radiographic, etc.), as well as eliminate defects in them.

It is allowed in vessels of groups 1, 2, 3, 4 and 5a not more than one, in vessels of group 5b not more than four, in heat exchangers not more than two butt joints available for visual inspection only on one side. The seams shall be made in a manner which ensures that the entire thickness of the metal to be welded (e.g. argon arc welding of the seam root, backing ring, locking joint) is penetrated. The possibility of using the remaining backing ring and lock joint in the vessels of the 1st group should be justified in the design in the established manner.

Longitudinal welds of horizontally installed receptacles shall be placed outside the central angle of 140 ° of the lower part of the shell if the lower part is not accessible for visual inspection, as shall be indicated in the design.

Welds of vessels shall not be covered by supports. 

Overlapping of joint crossing points is not allowed.

Longitudinal seams of adjacent shells and seams of bottoms in vessels of groups 1, 2, 3 and 4 should be displaced relative to each other by three times thickness of thickest element, but not less than 100 mm between axes of seams.

1.8. Procurement activities.

Blanks can be cast, forged, stamped and rolled. The process of procuring rolled stock parts can include editing, marking, edge machining, bending, and cleaning.

Edit. As a rule, it is produced in a cold state by creating local plastic deformation. In order to avoid significant loss of plastic properties, the extent of elongation of the most deformed fibers is usually limited by the pour point.

For steel St.09G2S, Δ is allowed at cold straightening up to 1% and at cold bending up to 2%. Based on this, the stroke of the pusher during straightening on presses and the radius of the roll during straightening in rollers are limited. The sheet-adjusting rolls may be 411 rolls or more. Straightening is achieved by bending and stretching by repeatedly passing sheets between the upper and lower rows of rolls.

Markup. Individual marking is time consuming. Mapping is more productive, however, the production of special mapping templates is useful only for mass production or for repeated single-production designs.

Edge cutting and machining. To cut sheet material, guillotine scissors and press scissors are used. Cut sheet is turned between lower and upper knives until stop, clamped by clamping and pressing of upper knife is performed by chipping. Support means in the form of rollers or ball supports are often used to facilitate the supply of sheet material to the scissors. Sheets from 3 to 25mm thick can be cut with disk scissors. Sometimes, to obtain parallel edges of the sheet, the disc knives are located directly on the rolls of regular rollers.

Oxygen separation cutting is extremely widely used. Manual and semi-automatic cutting is usually carried out according to markings, automatic - using copy devices.

Preparation of edges for welding. Stitching or milling of edges on machines is usually done in the following cases: 1) to form chamfers that have a complex shape; 2) if the specification requires edge treatment after cutting with scissors; 3) to ensure accurate dimensions of the part; 4) to improve the surface of some steels of increased strength after manual gas cutting. When stitching long edges of sheets of large size, edge-building machines are used, and end-cutters are used for processing.

Flexible. The most common works include rolling. In cold rolling, the ratio of bend radius to metal thickness shall be at least 25 (for low alloyed steels).

With a lower ratio, it is usually recommended to roll in a hot state. When folded in the rolls, the end portion of the sheet remains almost flat. In three-roll rollers, the width of this section can be 150200 mm. When the sheets are bent in the four roll rolls, this portion is from S to 2S depending on the length of the edge to be bent. After this operation, the sheet is installed in the rolls, the shaft axis and the sheet edge are aligned, and folding begins at the middle of the sheet.

Cleaning for welding. It is carried out manually with abrasive circles or brushes, on sandblasting plants, on shot blasting plants, by chemical means and with the help of ultra-sound. Cleaning with shaped circles and brushes is not productive. Cleaning at the sandblasting plant is more productive and widely used, but it has a significant drawback - it contaminates the air of the workshop. Shot blasting plants using metal sand from bleached cast iron are no less productive than plants using dry quartz sand;

pollution occurs to a much lesser extent.

During hydraulic jet cleaning, no contamination occurs with pulp (mixture of sand and water) sent to the part with compressed air.

1.11. Selecting Welding Modes

The determination of the welding mode usually begins by selecting the diameter of the electrode, which is assigned depending on the thickness of the sheets when welding butt joint seams and on the seam leg when welding corner and T joint seams.

1.12. Selection of welding equipment

The main welding equipment is the welding arc power supply, which shall meet the following requirements:

- provide the arc current and arc voltage required for this welding process;

- have the necessary appearance of external characteristic to fulfill the condition of stable arc burning;

- have such dynamic parameters that normal arc excitation and minimum spray ratio can be ensured.

Conclusion

In accordance with the initial data - the design drawing, technical requirements for the welded structure, the production program, work was carried out on the technology of assembly and welding of the apparatus and the requirements for reliability and service life of the structure, the main materials for welding were selected; to ensure the equal strength of welds with the main material, appropriate welding materials were selected, methods for producing an undisturbed joint were chosen, and the equipment necessary for welding the structure; welding modes are calculated, information on methods for inspection of welded joints is given. The tank passed the strength calculation based on the selected materials and the main manufacturing parameters for operation in the design mode.

To increase productivity and improve working conditions for workers, as well as improve the quality of welds, mechanized welding in the environment of protective gas was replaced by automatic welding under a flux layer, thereby saving material resources due to the use of less qualified personnel.

During welding of welded structure elements: bottoms to shell housing, the following technical and economic parameters can be provided:

- stability of production;

- quality of welds;

- reduction of material costs;

The proposed welding technology ensures cost-effectiveness when it is introduced into production.

The economic effect is 230,850 rubles/year.