How are welders classified into different grades and how do they get certificates?

Welder technical level standards

1. Occupational definition

Use welding equipment and tools, and use welding materials to weld, cut, and carbon arc gouging the workpiece Waiting for processing.

2. Scope of application

Manual arc welding, submerged arc welding, gas shielded welding, electroslag welding, plasma arc cutting, carbon arc gouging, casting welding repair, etc.

3. Technical level line

Elementary, intermediate and advanced levels

Junior welder

1. Knowledge requirements:

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1． The name, model, specifications, performance, structure, usage rules and maintenance methods of self-use equipment.

2． The names, specifications, uses, usage rules and maintenance methods of self-use instruments and meters.

3. The names, specifications, uses, usage rules and maintenance methods of self-used tools, clamps, measuring tools and protective equipment.

4． Types, grades, mechanical properties and welding properties of commonly used metal materials. Basic knowledge of metal heat treatment.

5. Types, brands, specifications, application scope, usage and storage methods of welding rods, welding wires, flux and tungsten electrodes.

6． The influence of the properties and purity of commonly used welding shielding gases (argon, carbon dioxide) on welding quality.

7. Basic knowledge of mechanical drawings and the representation methods and meanings of weld symbols and groove forms.

8． Common mathematical calculation knowledge.

9. Types, characteristics, scope of application and operation methods of commonly used welding methods.

10. The scope of application and connection methods of forward connection and reverse connection.

11. Basic concepts of welding process parameters.

12． Knowledge of welding methods of commonly used carbon steel, low alloy steel, cast iron, and non-ferrous metal materials, and selection of welding materials and welding process parameters.

13. Commonly used welding joint forms, groove forms and groove angles, root gaps, blunt edges, etc. and their effects on welding deformation and welding quality.

14. The basic principles of carbon arc gouging, tools, equipment, process parameters, operating methods and scope of application.

15. The welding process of general weldments and the methods of repairing welding defects.

16. Types, causes, hazards and prevention methods of common welding and carbon arc gouging defects.

17. Basic knowledge of working at heights, in narrow rooms or in containers.

18． Safety technical regulations.

2. Skill requirements:

1. Use and maintenance of self-used welding equipment and auxiliary equipment.

2． Use and maintain self-employed tools, clamps, tires, measuring tools and protectors, and repair and replace electric welding clamps, gas shielded welding guns, gouging guns, etc.

3. Use and storage of commonly used instruments and gas bottles.

4． Baking, use and storage of welding materials.

5. Understand welding parts diagrams and simple component diagrams.

6． Select welding and gouging process parameters and make preparations before welding.

7. For general welding parts of low carbon steel and low alloy steel, use carbon arc gouging to clean the welding root.

8． Carry out correct preheating and temperature measurement of weldments.

9. Check the appearance quality of welds, identify welding defects on the weld surface, and measure the groove and weld dimensions.

10. Hand arc welding and gas shielded welding in flat and horizontal welding positions.

11. Correctly implement safety technical operating procedures.

12． Meet the requirements of job responsibility system and civilized production.

3. Work examples:

1. For butt welds of low carbon steel plates with a plate thickness of 10-14mm, hand arc welding is performed in the flat and horizontal welding positions, requiring a V-shaped groove and single-sided welding and double-sided forming.

2． Butt welds of low carbon steel plates with plate thickness of 7-12mm, manual tungsten arc welding or carbon dioxide gas shielded welding in flat or horizontal welding positions require V-shaped grooves.

3. Manual arc welding and gas shielded welding of fillet welds of low carbon steel plates in flat or horizontal welding positions (leg size 6mm), submerged arc welding and carbon dioxide gas shielding of fillet welds of low carbon steel plates in flat welding position (leg size 10mm) weld.

4． Manual arc welding of low carbon steel pipes with a diameter greater than 89mm and a wall thickness less than 12mm butt-jointed horizontally.

5. Welding of beams and columns.

Intermediate welder

1. Knowledge requirements:

1. Types, models, performance, structure, usage rules and adjustment methods of commonly used welding equipment.

2． Basic knowledge of common tools, fixtures, tire tools, and protective equipment for repair.

3. Estimation methods of steel weldability and general knowledge of the effects of different natural conditions on weldability.

4． The main chemical components and functions of welding rod coating, flux, welding wire, tungsten electrode, and shielding gas, as well as the principles for selecting welding rods, welding wires, and flux.

5. Knowledge on the welding performance, welding methods, welding process parameters and welding material selection of commonly used alloy steel, stainless steel, cast iron, and non-ferrous metal materials.

6． Commonly used welding process parameters, the relationship between various parameters and their impact on welding quality, and basic knowledge of preparing process specifications.

7. The concepts and purposes of preheating before welding, interlayer insulation, slow cooling after welding, postheating, and postweld heat treatment.

8． The composition and characteristics of the welded joint, the structure of the heat-affected zone, changes in mechanical properties and influencing factors.

9. Principles, processing methods and quality requirements for bevel form selection.

10. The basic concepts of welding deformation and stress, the causes, hazards and control methods of various welding deformations and stresses.

11. The basic principles, types, uses, operating methods and influence of process parameters on quality of plasma arc welding and cutting.

12． The purpose and operation method of surfacing welding, the causes of welding defects and the methods to prevent and repair them.

13. Commonly used welding inspection methods, general knowledge of identification and assessment of welding defects.

14. Prevention and repair methods of welding defects.

15. General knowledge of machining and basic knowledge of welders and electricians.

16. Basic knowledge of preparing process procedures.

17. Production technology management knowledge.

2. Skill requirements:

1. Inspection, adjustment and troubleshooting of commonly used welding equipment.

2． Correct use and maintenance of commonly used welding equipment and auxiliary equipment.

3. Repair and improve tools and fixtures for your own use.

4． Understand welding component diagrams and draw general parts sketches.

5. Welding rod process performance test.

6． Welding of inner and outer circumferential seams and longitudinal seams of cylindrical parts.

7. Welding of high-pressure vessels and product parts subject to impact in flat, vertical and horizontal welding positions.

8． Welding of non-ferrous metals and alloy steel.

9. Determine the location and extent of welding defects (cracks, slag inclusions, pores, incomplete welding, etc.) based on the radiographic inspection films.

10. Analyze the causes of welding defects and repair them until they are qualified.

3. Work examples:

1. Butt welds of medium carbon steel plates and low alloy strength steel plates with a plate thickness of 10-16mm, and manual arc welding in flat, vertical and horizontal welding positions require V-shaped grooves and single-sided welding and double-sided forming.

2． Low-alloy steel pipes with a diameter of 273-362mm and a wall thickness of 30-50mm are provided with U-shaped grooves and butt joints. The base, transition and cover surface are made by manual tungsten arc welding in the horizontal rotation position.

3. Fillet welds of medium carbon steel plates and low alloy strength steel plates with a plate thickness of 10-20mm (the leg size is not greater than the minimum specimen thickness), hand arc welding and gas shielded welding in flat or horizontal welding positions.

4. Butt jointing of low-alloy strength steel pipes with a diameter of 38-60mm and a wall thickness of 3-6mm, and manual arc welding in horizontal fixed and vertical fixed positions.

5. Argon arc welding of butt welds of austenitic stainless steel plates with plate thickness greater than 4mm.

6． Welding and welding repair of workpieces of corresponding complexity.

Advanced Electric Welder

1. Knowledge requirements:

1. Methods for maintenance, adjustment, commissioning and acceptance of various welding equipment.

2． Test methods for weldability of welded joints and new materials.

3. Calculation knowledge of weld strength.

4. Methods to control welding deformation and welding stress of complex components and the relationship between stress and deformation.

5. Welding methods for multi-layer high pressure vessels.

6． Basic knowledge of welding metallurgy.

7. Methods for preparing welding process regulations and process details for complex products.

8. Quality analysis of complex and critical products and treatment methods of waste and defective products.

9． Basic knowledge of microcomputer applications.

10. Basic knowledge to increase productivity.

2. Skill requirements:

1. Adjustment, commissioning and acceptance of welding equipment.

2． Welding of dissimilar metals (mild steel and stainless steel, steel and non-ferrous metals, etc.), welding of stainless composite steel plates.

3. Welding testing of new materials and welding process qualification.

4. Prepare welding process specifications for multiple welding method combinations.

5. Welding of various high-pressure and ultra-high-pressure vessels and components withstanding huge impact forces.

6． Welding in any welding position.

7. Trial production and quality appraisal of complex new products.

8. Solve key technical problems in welding production.

9． Evaluate the workmanship of welding materials.

10. Apply and promote new technologies, new processes, new equipment, and new materials.

3. Work examples:

1. Welding of alloy steel.

2． It can withstand the welding of low, medium, high and ultra-high pressure pipes and pipes of any specifications and in any position.

3. Welding of dissimilar metals in various joint forms, any specifications and any spatial location.

4. Welding repair of complex castings.

5. All-position welding of high-pressure and ultra-high-pressure vessels and components withstanding huge impact forces.

6． Welding and welding repair of workpieces of corresponding complexity.

Methods of acquisition: through study at corresponding vocational and technical schools; through participation in corresponding training and examinations at the vocational training center of the labor and social security department.