GOST 30430-96

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  ГОСТ 30430-96

GOST 30430−96 arc welding of structural cast irons. Requirements for technological process

GOST 30430−96

Group В05

INTERSTATE STANDARD

ARC WELDING OF STRUCTURAL CAST IRON

Requirements for technological process

Arc welding of structural cast irons.
Requirements for technological process

ISS 25.160.10
AXTU 0072

Date of introduction 2002−01−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 72 «welding and allied processes», Institute of electric them. E. O. Paton of the National Academy of Sciences of Ukraine

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 10 dated 03.10.96)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated January 16, 2001 N 13-St inter-state standard GOST 30430−96 introduced directly as state standard of the Russian Federation from January 1, 2002.

4 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard applies to the processes of manual and mechanized arc welding used in the correction of defects grey cast iron, repairing broken cast iron parts and creating litosfernyh products from cast iron.

2 Normative references

The present standard features references to the following normative documents:

GOST 12.1.005−88 standards System of labor safety. General hygiene requirements for working zone air

GOST 12.2.032−78 System safety standards. Workplace while performing work while seated. General ergonomic requirements

GOST 12.2.033−78 System safety standards. Workplace while performing work while standing. General ergonomic requirements

GOST 12.3.002−75 System safety standards. The process of production. General safety requirements

GOST 12.3.003−86 System of standards of occupational safety. The work of electric welding. Safety requirements

GOST 12.3.004−75 System safety standards. Heat treatment of metals. General safety requirements

GOST 12.3.009−76 System of standards of occupational safety. The work of loading and unloading. General safety requirements

GOST 12.4.028−76 System of standards of occupational safety. Respirators SB-1 «Petal». Specifications

GOST 12.4.034−85 System safety standards. Means of individual protection of respiratory organs. Classification and marking*
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* On the territory of the Russian Federation GOST 12.4.034−2001 «System of occupational safety standards. Means of individual protection of respiratory organs. Classification and marking» here and hereinafter. — Note the manufacturer’s database.

GOST 12.4.035−78 System safety standards. Protective face shields for welders. Specifications

12.4.123 GOST-83 System of standards of occupational safety. Collective protection from infrared radiation. General technical requirements

GOST 17.2.3.02−78 Protection of nature. Atmosphere. Rules for establishing permissible emissions of harmful substances by industrial enterprises

GOST 1215−79 Casting of malleable cast iron. General specifications

GOST 1412−85 Cast iron with lamellar graphite casting. Brand

GOST 1585−85 antifriction Iron for castings. Brand

GOST 3242−79 welded Connections. Quality control methods

GOST 6996−66 Welded joints. Methods for determining the mechanical properties

GOST 7293−85 Cast iron with spheroidal graphite casting. Brand

GOST 9466−75 covered metal Electrodes for manual arc welding of steels and surfacing. Classification and General specifications

GOST 14651−78 electrode holders for manual arc welding. Specifications

GOST 16130−90 Wire and rods of copper and alloy copper-based welding. Specifications

GOST 18130−79 Semi-automatic devices for arc welding with consumable electrode. General specifications

GOST 19200−80 Casting of iron and steel. Terms and definitions of defects

GOST 21694−94 welding mechanical Equipment. General specifications

GOST 26271−84 cored Wire for arc welding of carbon and low-alloy steels. General specifications

GOST 26358−84 cast iron Castings. General specifications

GOST 28394−89 the vermicular graphite Iron for castings. Brand

N 1009−73 Sanitary rules during welding, surfacing and cutting of metals

3 Definitions

In this standard use the following terms with respective definitions:

3.1 graphicsimage elements: Chemical elements, promotes the release of graphite phase during solidification of cast iron.

3.2 liteware product: a Product obtained by welding of castings (cast iron) workpieces.

3.3 modifying elements: Chemical elements that change (modification) in the form of graphite from lamellar to globular during solidification of cast iron.

3.4 the sub-form: Shape, made of moulding material at the place of defect in the casting to hold the liquid metal in the welding of the defect and give the restored part of the casting of the desired shape and size.

Definition of casting defects according to GOST 19200.

4 Symbols and abbreviations

 — welding current, A;

 — the voltage at the welding arc;

 — welding speed, m/h;

 — the speed of electrode wire feeding, m/h;

 — rupture strength, MPa;

 — elongation, %;

ND — normative document.

5 Requirements

5.1 Requirements for castings, parts, workpieces and materials

Arc welding shall be castings, details and preparations from gray cast iron (with lamellar graphite) all grades according to GOST 1412, ductile iron (with flake graphite form) of all grades according to GOST 1215, antifriction (with lamellar graphite) all grades according to GOST 1585, high strength (worm-like graphite) of all grades according to GOST 28394 and high-strength (spheroidal graphite) all grades according to GOST 7293.

As electrode materials for arc welding of cast iron using coated electrodes (hereinafter as electrodes), cored wire and wire, of solid section based on ferrous or non-ferrous metals.

Electrode materials for welding cast iron needs to ensure the reception of the weld metal (weld metal) the weld joint, the chemical composition and structure similar to the base metal or (in the case of electrodes based on Nickel, copper or iron) is more malleable than cast iron, alloy.

Types of weld metal (deposited metal) and the corresponding recommended brands and grades of welding materials for arc welding of cast iron are given in table A. 1.

5.1.1 requirements for the composition, characteristics, properties of welded materials

Chemical composition and mechanical properties of welded cast iron construction shall conform to the requirements of GOST 26358.

Electrodes for manual arc welding of cast iron for size and strength of the coating, welding-technological properties, packaging, storage and transportation shall meet the requirements of GOST 9466.

Flux-cored wire for mechanized arc welding of cast iron in terms of surface condition, filling powder, the size and mass of a coil, welding-technological properties, packaging, storage and transportation shall meet the requirements of GOST 26271.

Wire, of solid section for mechanized arc welding of cast iron in terms of surface condition, size and weight of the rolls, welding-technological properties, packaging, storage and transportation shall meet the requirements of GOST 16130.

Molding sand used for the manufacture podfarm must retain the molten metal bath and getting the desired shape and size of the defect is brewed in accordance with the requirements of ND on the casting or part.

5.1.2 requirements on the methods and procedure of training materials, preparations

The removal of the molding mixture, combustion, rust, scale, oil and other impurities on castings, parts or workpieces carry out mechanical Stripping, chemical etching, burning by gas flame, boiling in alkaline baths and other ways. The choice of cleaning method and the procedure of its implementation are established ND for iron castings, a part or workpiece.

Preparation of iron workpieces for welding should include:

the cleaning of the surfaces of the workpieces in the weld area;

the execution of the cutting;

degreasing edges;

the Assembly of workpieces using clamps or tacks;

the installation in the desired position.

Preparation of iron castings under the welding defects must include:

the cleaning of the surfaces of the castings in the place of the casting defect;

cutting defects to their complete removal;

manufacturer podfarm in place end-to-end or edge defects.

The preparation of the damaged cast iron parts under restoration welding should include:

the cleaning of surfaces of details at the site of injury;

the execution of the cutting;

spot drilling the ends of cracks;

degreasing edges;

Assembly with broken parts or panels with the use of tacks;

the installation in the desired position.

In the preparation of iron workpieces for welding litosfernyh products, as well as in the cutting of cracks in the damaged parts with wall thickness up to 30 mm should be used only mechanical methods, and methods of thermal cutting (gouging) is not allowed.

In the preparation of castings with wall thickness more than 30 mm for repair of casting defects by welding is allowed to use for cutting air arc cutting (gouging) or specialized electrodes for cutting.

The ends of the cracks on the damaged parts of the iron should be severity. For reliable detection of all cracks should be used etching the bare surface of the weak solution (2−4%) of nitric or hydrochloric acid. The order of execution of the drilling and etching of cracks is determined by ND.

Podfarm for defective casting parts made of refractory forming mixture of the following composition: sand-quartz — 4 pieces, white clay refractory — 4 parts graphite to 2 parts. The procedure for preparing the mixture and applying it to the casting set ND for casting. For the manufacture of podfarm allowed to also use a graphite plate, refractories, etc.

5.1.3 Requirements for methods of control of materials, semi-finished

Input control of materials and workpieces is carried out in the parameters and methods established in the regulatory documents for products.

In the preparation of iron workpieces for welding in liteware product check:

compliance grades of cast iron billets cast iron liteware brand of products;

the absence of an external casting defects: cracks, cavities, shrinkage porosity, rihlat, junctions, etc.;

matching the form and appearance of blanks to drawings specifications.

In the Assembly of workpieces for welding in liteware product check:

match the shapes and main dimensions assembled under welding products working drawings;

compliance gap root cutting for welding to a specified value according to the standard documentation for a welded product;

the absence of traces of oil, grease and other dirt on the edges.

5.1.4 labeling Requirements for materials, preparations

Marking of materials and workpieces, as well as the sequence of application additional details of marking should be specified in regulatory documents for materials and blanks of a particular species.

5.1.5 the Norms of consumption of materials

Standards of consumption of basic materials should be specified in regulatory documents for products of specific types.

Approximate consumption of welding materials given in table A. 2.

5.2 requirements to the technological process

The main requirement for the technological process of arc welding of structural cast irons — ensuring the strength of welded joints and base metal. Only in certain cases specified in regulatory documents for castings and parts, allowed the deterioration of the mechanical properties of welded joints (and ) to 25% in comparison with the mechanical properties of the base metal.

The processes of manual and mechanized arc welding of cast iron is performed on DC straight or reverse polarity. Wire, of solid section or flux-cored wire should be fed into the welding zone continuously, without jerks and delays. The utilization rate of electrode materials must not exceed the limits in tables A. 3, A. 4.

5.2.1 requirements for the composition and sequence of operations of technological process

5.2.1.1 welding products

The technological process of arc welding litosfernyh products of cast iron includes the following operations:

preheating of the workpiece Assembly;

welding products;

quality control of welded joints;

test litosfernyh products.

Pre-heating of workpieces collected for welding, is performed in an electric furnace or a gas flame.

Arc welding of cast iron is carried out mainly mechanized methods using wires of solid section: PUNCH 11, the PUNCH 12, MN-25, etc. — without pre-heating (or pre-heated product to a temperature of 200−300 °C) or flux-cored wires PP-ANCH-5, PSW-7 etc. — with pre-heated product to a temperature of 400−600 °C. However, during welding of articles of cast iron is preferable the use of automated arc welding processes, since they are executed without interruption with a small flow of electrode materials. In the case of multi-pass welding process may be interrupted in the sweep of the stitches, the turning over of the product, changing welding conditions.

If necessary, the weldment is subjected to thermal treatment (annealing) to relieve residual welding stresses. The heat treatment conditions are set in accordance with ND on the welded product.

Requirements for the quality control of welded joints of cast iron in accordance with 5.8.

5.2.1.2 Correction of casting defects on the casting

The technological process of arc welding (welding) defects on ductile iron castings includes the following operations:

pre-heating the casting;

weld (welding) defects;

quality control of welded joints;

test casting with fixed defects.

Pre-heating castings with split defects and podvodkami they perform furnace, gas burners or on the furnace with coke.

Manual arc welding (welding) defects is carried out on the cast iron castings of grey cast iron with lamellar graphite electrodes ECH-1, ECH-2, CBS-5, castings of ductile cast iron with nodular graphite electrodes EEP-1.

Mechanized arc welding (welding) defects in the castings made of gray cast iron with lamellar graphite is carried out with the use of flux-cored wires PP-ANCH-2, PSV-7 on the casting of high-strength nodular cast iron — wire PP-ANCH-5.

Weld (welding) defects with pre-heating of casting are done only in the lower position.

Defects with the amount of weld metal to 100000 mmbrewed continuously from the edges to the center with jelly shrinkage. Defects with a large amount of deposited metal is divided into sections according to the form in the form of a circle (diameter 100 mm) or square (100x100 mm). Welding start section located in the deepest place. Next brew (fused) consistently plots with a thickness of about 10 mm with a small overlap of the welded areas. Between the welding of individual sections make small breaks for cleaning the surface of the weld (welding).

Slow cooling of the casting with infused defect is carried out using the same tools that are used for preheating.

If necessary, casting with fixed defects is subjected to heat treatment (annealing) to relieve residual welding stresses and to ensure machinability of welded joints mechanical tool. The heat treatment conditions are set in accordance with ND on casting.

Requirements to control the quality of iron castings with casting defects corrected in accordance with 5.8.

5.2.1.3 Recovery details

The technological process of arc welding broken or worn cast iron parts includes the following operations:

welding of damaged parts;

quality control of welded joints;

test reconditioned parts.

Pre-heating in arc welding the damaged cast iron parts are, as a rule, do not apply.

Manual arc welding of damaged cast iron parts is carried out with the use of covered electrodes for Nickel (SPD-3, SPD-4, MNCH-2), nielegalny (ODVV-1), copper (SPD-2, SPD-6) or iron (CBS-4) basis. Lead welding seams with a length of 30−50 mm with breaks for cooling and cleaning the seams. Long cracks split into sections with a length of 50−60 mm and the welding is carried out on sites in a particular order in accordance with ND on the recovered detail. In the same way lead welding broken parts or inserts. Welds made by electrodes with a rod of Nickel alloys, as a rule, prokovyvayut with a hammer directly after breakage of the arc. When using electrodes with copper rod hammering of seams required.

Mechanized arc welding of damaged cast iron parts is carried out using wires of solid section copper (MN-25) or Nickel (PUNCH 11, PUNCH 12) basis. Lead welding seams with a length of 60−80 mm (wire PUNCH-11 to 150 mm) with breaks for cooling. Long cracks split into sections with a length of 80−100 mm and carry out the welding of sections in a specific order in accordance with ND on the recovered detail. Allowed the welds to proceviat.

If necessary, the repaired part is subjected to heat treatment (annealing) to relieve residual welding stresses and to ensure machinability of welded joints mechanical tool. The heat treatment conditions are set in accordance with ND for detail.

Requirements to control the quality of the reconstructed welding cast iron parts in accordance with 5.8.

5.2.2 Requirements for modes and parameters of technological process

Arc welding of structural cast irons perform with the use of covered electrodes, cored wires and wires of solid section.

5.2.2.1 Modes of welding with coated electrodes

Recommended modes of manual arc welding of cast iron and the utilization factors of electrodes is given in table A. 3.

5.2.2.2 Modes cored welding wires

Recommended modes of welding of cast iron cored wires as well as the odds of using cored wires are given in table A. 4.

5.2.2.3 Modes of welding wire of solid section

Recommended modes of welding cast iron with wires of solid section are given in table A. 5.

5.3 Requirements for the main and auxiliary technological equipment

5.3.1 Requirements the main technological welding equipment

Elektrodvigateli for manual arc welding of cast iron electrodes with a diameter of 2−6 mm must meet the requirements of GOST 14651.

In mechanised arc welding of cast iron with wires of solid section or flux-cored wires basic process equipment must provide uniform feeding of the electrode wire into the welding zone with the speed of its melting point and maintaining at a predetermined level of mode parameters of welding, first welding current and arc voltage in accordance with GOST 18130.

The feed rate of the wire, of solid section adjust from 50 to 150 m/h, and flux-cored wire from 80 to 350 m/h.

Power supplies for mechanized arc welding of cast iron (welding converters or rectifiers, DC) must have rigid or dipping external characteristic.

5.3.2 Requirements for mechanical and auxiliary technological equipment

Mechanical equipment used in welding litosfernyh of articles of cast iron, shall conform to the requirements of GOST 21694.

Requirements for auxiliary technological equipment is installed in the design documentation for the product.

5.4 Requirements for process a snap

Requirements for process a snap set in the design documentation for the product.

5.5 performance Requirements of the workplace, production facilities

Plot for arc welding of cast iron needs to be located in a well-lit ventilated area, volume and area according to sanitary norms.

Organization of workplaces of welders shall conform to the requirements of GOST and GOST 12.2.032 12.2.033.

The area should be located the points of the manual and (or) mechanized arc welding device for prior, concomitant and subsequent heating of the workpieces or castings and parts, the equipped place for preparation of workpieces for welding (cutting defects, manufacturing podfarm on split defect, etc.), the equipped place for quality control of welded joints, the devices for drainage and containment of released during welding aerosols.

Depending on the weight of iron billets, castings or parts of land should be placed in the area of the workshop suitable lifting crane or other lifting mechanisms.

Food plot electricity must be from a separate distribution Board with capacity of 20−100 kVA (with number of posts from 1 to 5).

Posts for arc welding cast iron should be free of drafts.

5.6 Requirements for process control

Control performed at all stages of the arc welding of cast iron from the preparation of castings, parts and pieces to quality control of welded joints.

In preparation checking the cleanliness of surfaces cleaned for welding: no stains on them and defects foundry origin — shells, porosity, blockages, cracks, etc. To do this, use methods of visual control with the use of loupes and magnifying glasses, etching by weak solutions of acids for a more reliable detection of microcracks.

Check the correctness of preparation of cutting the weld: the angle of the edges, dullness and clearance in the root cutting, spot drilling the ends of cracks.

Podpora large casting defects check to ensure the shape and size of the casting after welding of the defect according to the requirements of the drawing on the product.

When performing welding with pre-heating of workpieces or casting the required preheating temperature is controlled with an accuracy of ±10 °C.

During the welding process, check the voltage and the welding current voltmeters and ammeters with accuracy class 0.5. Control of current and voltage are held at the beginning of the weld during continuous welding of major defects cored wire — periodically every 5−7 min.

5.7 test Requirements

The testing requirements set in the design documentation for the product or reconditioned part (casting).

Liteware if the product or reconditioned part (casting) work under pressure, then after welding subjected to a hydraulic test for tightness of welded joints of excess pressure of 0.2−1.0 MPa or «kerosene test». Conditions and parameters leak test set to ND the product or part.

5.8 Requirements for quality products

Weld cast iron, done arc welding, must ensure that the performance characteristics established by normative document for the product.

Welded joints of cast iron made with arc welding, is subjected to a visual inspection with the use of loupes or a magnifying glass with a two to fivefold increase. Visual inspection can reveal defects emerging at the surface: cracks, pores, undercuts, lack of penetration. Hairlike cracks, difficult to detect visually detect by color testing in accordance with GOST 3242.

Quality control of welds is permitted to carry out the stretching to failure of samples-«witnesses», is cut across a seam according to GOST 6996 of welded butt connections of iron, from which manufactured products, and welding technology of these products.

Internal defects: cracks, pores, slag inclusions, lack of fusion, etc. — with a thickness of up to 250 mm can be detected radiation method (x-ray or rays) in accordance with GOST 3242.

Depending on the purpose of the welded products and their operating conditions are established two levels of quality requirements.

First level: the mechanical properties of the weld metal and heat affected zone (rupture strength, elongation) should be no worse than the relevant mechanical properties of cast iron, made of welded parts. The weld metal (weld metal) must be processed by the cutting tool. The presence of cracks and pores is unacceptable.

Second level: mechanical properties of the weld metal and heat affected zone can be 25% worse than the corresponding mechanical properties of the base metal, the weld metal must be processed by the cutting tool. Cracks and through pores is unacceptable. The defects allowed in set ND for products made of cast iron.

Requirements for decorative welding surface defects this standard is not established, if the requirements for them are lower than for constructive welded joints.

5.9 labelling Requirements of products

Marking on litosfernyh products from cast iron by ND for the products.

5.10 Requirements for packaging, transportation and storage of products

5.10.1 Requirements for packaging and transportation

Requirements for packaging and transportation of castings, billets and welding consumables set to ND the corresponding product.

5.10.2 storage Requirements

Requirements for the storage of castings, billets and welding consumables set to ND the corresponding product.

5.11 security Requirements

Sanitary conditions in areas of arc welding of cast irons in terms of requirements to industrial premises, equipment, fixtures, heating, ventilation, and lighting shall satisfy health regulations during welding, surfacing and cutting of metals N 1009.

Welding should be performed in accordance with the requirements of this standard, GOST 12.3.003, 12.3.004 GOST, GOST 12.3.009, fire safety Regulations during welding and other fire works on the objects of national economy and Rules of technical operation of electrical installations of consumers and safety Regulations in the operation of electrical installations*.
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* There are «Interbranch Rules on labor protection (safety rules) for electrical installations» (SWEAT P M-016−2001, RD 153−34.0−03.150−00). — Note the manufacturer’s database.

The content of harmful substances in the air of working zone produced in arc welding of cast iron, shall conform to the requirements of GOST 12.1.005. If the ventilation system does not provide the required quality of the air environment in the working area of welding, it is necessary to use means of individual protection of respiratory organs according to the requirements of GOST 12.4.034.

In monitoring state of air environment at workplaces necessary to carry out the determination the welding fumes with the following definition in its composition of soluble, insoluble and adsorbed fluorides, Nickel, chromium, manganese, copper, silicon, iron and their compounds, and in gas phase, HF, SiF,and nitrogen oxides (in terms of NO).

When working in dusty conditions welders must use dust respirator SB-1 «Petal» according to GOST 12.4.028.

To protect the eyes, working from the welding arc radiation in the visible, ultraviolet and infrared regions, it is necessary to apply flaps welder according to GOST 12.4.035. Protection from thermal (infrared) radiation must comply with the requirements of GOST 12.4.123.

Overalls and safety shoes for welders should securely to protect them from sparks and molten metal splashes, harmful radiation, moisture and other environment factors according to GOST 12.3.002.

For protection of hands welders should ensure that gloves or gloves made of a resistant spray materials with low thermal conductivity.

When welding in conditions of high risk of electric shock welders, in addition to clothing, should ensure insulating gloves, galoshes and rugs.

When welding large iron casting with preheating it is necessary to use insulating blankets and to carry out the screening of the working zone of the welder.

Personal protective equipment must undergo periodic control examinations and tests within the deadlines set ND.

Workers associated with arc welding of cast iron must undergo preliminary and periodic medical examinations at least once a year.

5.12. Requirements to ensure environmental protection

For environmental protection in arc welding of cast iron should be used local suction that removes the welding fumes directly from the combustion zone of the arc, and torch for mechanized arc welding with built-in suction the welding fumes.

The solid component of the welding fumes produced during the arc welding of cast iron, must be deposited on the filters in the ventilation systems. For protection of atmospheric air from contamination by harmful substances produced during the welding works shall be provided for activities in accordance with the requirements of GOST 17.2.3.02.

5.13 qualifications of the production personnel

To work on arc welding of structural cast irons are allowed welders who have passed a course of theoretical and practical training and certified in accordance with the requirements of Rules of certification of welders with qualification not lower than category IV to perform manual arc welding and no lower than III to perform mechanized welding.

The order of training, certification and re-certification of production personnel is set by the enterprise performing the work.

Annex a (recommended). Recommended welding consumables, the estimated norms of consumption of welding mode

APPENDIX A
(recommended)

Table A. 1 — Recommended brands and grades of welding materials for arc welding of cast iron

Table A. 2 — Estimated norms of consumption of welding consumables in arc welding of cast iron

Table A. 3 — Recommended modes of manual arc welding of cast iron

Table A. 4 — Recommended modes of welding of cast iron cored wires

Table A. 5 — Recommended modes of welding cast iron with wires of solid section

The electronic text of the document

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M.: IPK Publishing house of standards, 2001