GENERAL PROVISIONS
In order to put the designs into production, the manufacturer draws up the technological documentation on the basis of the design documentation, the form and scope of which depend on the specifics of the production and the complexity of the products.
For unique structures, special technical requirements are developed.
ACCEPTANCE OF DESIGN DOCUMENTATION, INCOMING INSPECTION AND STORAGE OF ROLLED METAL PRODUCTS, WELDING CONSUMABLES, PAINT AND VARNISH MATERIALS, FASTENERS
1. All design documents received by the company must be reviewed and analysed in order to:
- identifying errors;
- checking the assemblability of structures (for typical objects);
- assessing the technological feasibility of the project;
- the economic viability of a design in a specific production environment is assessed;
- the design of the unit and the type of connections must be harmonised.
If the design documentation is checked positively, the company's technical manager decides whether the facility should be put into production. For complex and unique objects, the decision is taken by the technical council of the company.
Rolled metal products (rolled metal products), welding consumables, paintwork materials and fasteners supplied by suppliers must be checked by the company's technical control service for quantity, completeness and conformity with standards, technical specifications (TS), supply contracts and job orders.
2. The type and plan of the incoming inspection shall be determined by the technical services of the company, if necessary in agreement with the supplier.
3. An acceptance report must be drawn up for each accepted carload of rolled steel, type of steel, grade of steel, melt.
3.1 When accepting rolled steel, check that:
- theoretical weight quantities, grades and steel grades as per work orders, brands or tags of the supplier;
- absence of visible delaminations, cracks, pits, dents and general deformations in the rolled product, exceeding those permitted by the relevant standards and specifications.
3.2 If there are deviations from the standard or specification, a complaint report must be drawn up.
3.3 After acceptance, the additional marking of the rolled products shall be made by painting in white the certificate of acceptance number and in colour the steel grade in accordance with the company's system.
3.4 In the metal warehouse a computerised, card or journal record of the movement of the rolled stock by input and output shall be kept. The records should be kept for each section of rolled steel, taking into account the steel grade and the acceptance certificate number.
4. When accepting welding and coating materials and fasteners, the following rules must be observed.
4.1 Check that the accompanying document, which must include the name of the material, batch number and indicators showing compliance of the material with the requirements of the technical documentation (TDS), is available.
4.2 Determine the integrity of the packaging by external inspection.
4.3 Determine quantities of materials by weighing, counting by piece, theoretically.
4.4 The results of acceptance shall be documented in an acceptance report and included in the general material flow system of the company.
4.5 If necessary, mark the paint acceptance certificate number on the packaging and the expiry date on the packaging of the paints and varnishes.
5. Rolled steel shall be stored sorted by section and steel grade.
The rolled steel should be stored in closed rooms equipped with special devices allowing for mechanisation of intra-warehouse operations.
Rolled sections should be stored in racks with separating stands, and rolled sheets should be stored in specially equipped places served by cranes with magnetic washers.
Steel coils should be stored vertically or on special pallets in a horizontal position. Cranes handling steel coils must be equipped with special grippers.
Store the rolled metal products in mechanised warehouses in accordance with the design and technological documentation for the warehouse in question and the company's instructions.
It is possible to carry out temporary storage (for 3 months from the date of shipment by the manufacturer) of rolled section products in specially equipped racks outdoors.
6. Welding consumables (welding wire, electrodes, flux, flux cored wire) shall be stored separately by grade and batch in a warm and dry room in the original packaging or special containers.
7. Paint and varnish materials should be stored in their original container in specially equipped rooms ensuring fire safety and environmental protection.
8. Fasteners (bolts, nuts, washers) must be stored in their original packaging or in special containers indoors. In the case of long storage periods, the preservative protective coatings must be renewed if necessary.
PREPARATION OF ROLLED METAL PRODUCTS, WELDING CONSUMABLES AND PAINTWORK MATERIALS BEFORE THEY ARE FED INTO PRODUCTION
1. The rolled product must be checked for compliance with the accompanying documentation, cleaned of moisture, snow, ice, oil and other impurities before being fed into production.
2. Straightening of rolled stock, depending on the profile, must be performed cold on straightening and section straightening machines and presses.
3. Straightening of steel by local heating with a gas torch flame is allowed, but the temperature of the heating zone shall not exceed 800 °C for hot-rolled and normalized steels, and 700 °C for thermally improved steels.
4. After straightening, the rolled product shall comply with the following requirements:
4.1 nbsp;Not cracked or delaminated. Local indentations in the thickness and width of the rolled product to a depth not exceeding twice the minus tolerance for the type of rolled product specified in the relevant GOST or TU, but in all cases not exceeding 1 mm in thickness and 3 mm in cross-sectional dimensions are allowed.
4.2 The non-conformity of the plane sections of the rolled section shall not exceed the respective tolerances specified in GOST or TU for that type of product.
4.3 The deflection limits of the rolled section along the entire length of the element shall not exceed 0.001 l (10 mm), and the local buckling deflection shall not exceed 1 mm over the length of 1 m.
4.4 Flatness of sheet metal shall comply with GOST 19903.
5. Welding materials shall be supplied to the workplace labelled in the quantity required for the day's work.
5.1 Welding wire shall be cleaned of rust, grease and other contamination to a metallic sheen (except copper-coated wire), coiled, taped or wound on reels.
5.2 Electrodes and fluxes shall be calcined as specified in GOST or TU and data sheets for the type of welding material.
5.3 Tinned wire shall be cleaned, calcined and rewound in coils, cassettes or on reels.
6. Paintwork materials must be adjusted to the parameters specified in the regulations and technical data sheet for the specific material before they are used.
Preparation of paintwork materials for use consists of stirring until a homogeneous consistency is obtained without any residue at the bottom of the container, adding hardeners, siccants and other additives in the required quantity, diluting to working viscosity and filtering.
7. All paint preparation operations must be carried out in the paint preparation area.
The temperature of the paint material must be the same as the air temperature in the paint preparation room, for which the material must be received from the warehouse at least one day before application. The temperature in the paint preparation room must be at least +15 °C.
8. Paintwork materials must be diluted to working viscosity with solvents in accordance with the material-specific data sheets and process regulations.
9. The working viscosity of paintwork materials shall be determined in accordance with GOST 8420 by a VZ-246 type viscometer.
10. Paint and varnish materials prepared for use shall be delivered to the workplace in closed containers. If the consumption exceeds 200 kg (one item) per shift, it is advisable to supply paint materials centrally by pipe.
CUTTING AND MACHINING IN THE MANUFACTURE OF PARTS
1. The cutting of rolled sections can be done on press cutters, dies, friction and abrasive saws, toothed saws, hand, machine and thermal cutting without subsequent machining of the workpiece ends. These machining methods are acceptable for all steel grades and all structural conditions.
2. Regardless of the machining method, the ends of the rolled section parts shall be free of cracks, burrs and blockages exceeding 1 mm.
3. Cutting of sheet metal shall be performed with guillotine shears, notching machines, punches, manual and machine thermal cutting.
4. Cutting of sheet metal on guillotine shears, notching machines and punches shall not be carried out in the manufacture of parts:
- of steels with a standard yield strength of more than 350 MPa;
- thicknesses greater than 25 mm in steels with a yield strength greater than 275 MPa;
- thicknesses over 16 mm in steels with a yield strength of 285-350 MPa.
5. Cutting of sheet metal on guillotine shears, notching machines and punches is prohibited in the manufacture of parts of all steel grades:
- tensile structures whose longitudinal edges remain free after assembly and welding, including butt joint linings;
- the design of the rafters, trusses and sub-trusses, and conveyor gallery spans.
6. Edges of parts after cutting with guillotine shears, notching machines and punches shall not have cracks, splits, burrs and blockages exceeding 1 mm.
7. Unrestricted cutting by guillotine shears, notching machines and punches followed by machining the edges to a minimum thickness of 0.2 of the sheet thickness is possible.
8. In all other cases, except those mentioned above, cutting with guillotine shears, notching machines and dies shall be permitted without restriction.
9. Parameters of machining modes of structural parts should be determined taking into account the main indicators of mechanical properties of rolled steel: yield strength, tensile strength, relative elongation as well as hardening modulus. The recommended values of these parameters for use in calculating the mode parameters are given in Appendix A.
10. Thermal cutting is possible in the production of sheet metal parts of all steel grades for all operating conditions.
11. Edges of parts produced by heat cutting shall be cleaned of burr.
12 The tensile edges of sheet metal parts of structures, edges of fittings remaining loose after assembly and welding in trusses and sub-trusses, conveyor gallery spans shall comply with the following requirements:
- the surface roughness must not exceed 0.3 mm;
- individual areas of the edges which do not meet the specified requirements as well as gouges which do not lead the size of the part out of tolerance, corrected by smooth scraping with an abrasive wheel or by welding with special technology, followed by scraping the areas of rectification with an abrasive wheel moved along the edge.
Edges of parts that do not meet these requirements must be machined.
13. In all other cases, except in clauses 9-12. In all other cases, apart from clauses 9-12, the edges of sheet metal parts that have been thermally cut may have a roughness of up to 1.0 mm, and individual gouges of up to 1.5 mm. Cutting defects shall be corrected in accordance with clause 11 of this regulation.
14 Welding bead preparation shall be carried out by thermal cutting or machining. The surface finish shall comply with the requirements given in 7.12. The geometric dimensions and shape of the bevelling shall comply with the requirements of the welded joint standards.
15. The deviations of the edge lines of sheet metal parts to be assembled and welded, regardless of the method of processing, shall comply with the requirements of the standards for welded joints.
16. End faces and surfaces of parts directly transmitting support pressures by close contact shall be machined.
17. The sharp edges of the end faces of parts intended to be hot-dip galvanised or used in environments with medium or high corrosivity shall be blunted by not less than 1.0 mm.
18. Part tolerances shall be established in the design documents. In the absence of tolerances in the design documents, the data given in Table 4 must be used.
19. Control of geometric dimensions of parts is carried out with measuring tools, as well as with a set of styli according to TU 2-034-225-87. The roughness values of the workpiece ends are checked visually using reference samples.Download document