What Is a Welding Rod?

The welding rod is composed of a welding core and a coating. Welding electrode is to evenly and concentrically coat the coating (coated skin) on the core outside the metal core. Different types of electrodes have different cores. The welding core is the metal core of the welding rod. In order to ensure the quality and performance of the weld, the content of each metal element in the welding core is strictly regulated, especially the content of harmful impurities (such as sulfur, phosphorus, etc.) should be strictly controlled. The limit is better than the base material.

The electrode model is divided according to the mechanical properties of the deposited metal, the type of coating, the welding position and the type of welding current. The method of preparing the electrode model is as follows: the letter "E" indicates the electrode; the first two digits indicate the minimum tensile strength of the deposited metal. ; The third digit indicates the welding position of the electrode. "0" and "1" indicate that the welding is applicable to all-position welding (flat, vertical, vertical, horizontal), "2" indicates that the electrode is suitable for flat welding and flat welding, "4" indicates that the electrode is suitable for downward welding; when the third and fourth digits are combined, it indicates the type of welding current and the type of coating. After the fourth digit, "R" is used to indicate the resistance to moisture absorption; "M" is used to indicate the resistance to moisture absorption and the mechanical properties of the electrode; "-1" is used to indicate the impact resistance of the electrode.

CMC-EMagic6 electrode HRC 54 592.6 3.2

CMC EMagic6 is a high-efficiency knife-edge electrode, ideal for achieving low current and high fill rate. After welding, the molten gold has excellent toughness and impact resistance, full and smooth, good adhesion, automatic shelling, and can be machined; suitable for cold work steel Damage surfacing, especially suitable for large stamping die cutting parts. For the production of shearing tools, shear edges can also be made by overlay welding on low alloy or general steel.

CMC-EMagic10 electrode HRC 55 582.5 3.2

CMC EMagic10 is a high-efficiency knife edge electrode with high W and Cr content, ideal for low current and high fill rate; suitable for high-speed impact stamping die blades and punches, the molten metal is full and smooth after welding, and has good adhesion Automatic shelling, machining, and wear resistance in high-speed and high-temperature stamping working environment; especially suitable for repairing and surfacing welding of mold damage after hardening, only one layer can obtain higher hardness. Molten gold can be quenched with SKD11 and still has high hardness.

CMC-Emagic7 electrode HRC 52 55 3.2 * 350mm

CMC-Emagic7 is a magical electrode that can be directly welded to cast iron and cast steel. It has good welding adhesion and high hardness from the first layer. If you pay attention to the temperature between passes, it will not increase with the number of layers. Reduce the hardness; In addition, it is directly welded to the heat-treated Cr12MoV steel with high hardness performance. The special alkaline coating can reduce the generation of pores; it can be used for flat welding, vertical welding and fillet welding. Welding efficiency is slightly worse at AC welding.

CMC-E58 Electrode HRC 57 ~ 59 2.4, 3.2, 4.0

Abrasion resistance, high hardness and stability. Suitable for cold work steel damage surfacing, especially for cutting corners and edges of cold forging dies, calendar dies, knife dies, automotive stamping dies, and metal stamping dies. For the production of shear tools, it can also be used as a shear edge by overlay welding on low alloy or general steel. It can also be applied to the hard surface making of wear-resistant parts.

CMC-ECI55 electrode HRC 55-58 3.2 * 350mm

It is especially suitable for R-angle repair of deep-drawing molds and the production of drawn parts with high hardness. It can be directly welded to cast-iron molds GGG70L, FCD, GM241, etc ... The molten gold is dense, has high wear resistance and hardness, and is easy to polish. It is a high-efficiency electrode (120% fill-in efficiency). Ductile iron, gray iron and flame-quenched cast steel can also be directly surfacing.

CMC-E46N electrode HRC 45-48 2.4, 3.2

Welding directly on cast iron is very effective for metal wear of stamping dies. The first layer of the weld metal is an austenite structure; starting from the second layer, the martensite structure has good wear resistance. Flame hardened cast iron can also be directly welded.

CMC-E46H welding electrode HRC 44-49 3.2 * 350mm

Particularly suitable for R-angle repair and drawing of Mo-Cr cast iron molds. The molten gold is dense and easy to polish to prevent scratches on the sheet metal. It has high hardness and is suitable for the production of high-strength drawing bars. Ductile iron, gray iron and flame-quenched cast steel can also be directly welded.

CMC-E45 electrode HRC 48 ~ 52 2.6, 3.2, 4.0

It is a medium hardness steel electrode with good bonding properties, suitable for air-cooled steel, cast steel: such as ICD5, 7CrSiMnMoV, etc. Automotive sheet metal cover molds and large metal sheet metal stamping dies can be used for repairing the drawing and stretching parts, and can also be used for hard surface production.

CMC-E64N welding electrode 3.2 * 350mm

Welding electrodes for cast iron have high strength and good plasticity. Applicable to gray cast iron and nodular cast iron, which can be machined.

CMC-ENCD electrode HRC 25 28 3.2 * 350mm

Can be directly welded on cast iron, especially suitable for welding repair of MoCr cast iron and nodular cast iron. It is a low-hardness iron-based cast iron electrode, which can be processed after welding, and because it is very close to the composition of cast iron, it does not cause the problem of color difference of general cast iron electrodes, and it can be heat treated with the cast iron after welding. Good welding performance, no pores and cracks.

CMC-E62N welding electrode 3.2 * 350mm

It is especially suitable for cast iron molds, because the nickel content is reduced, so the cost can be reduced, and the hardened surface of the cast steel mold can be used as a base buffer layer.

CMC-E12HA electrode HRC 57-59 2.4, 3.2, 4.0

Excellent red stripe, widely used in hot forging, cold stamping, abrasion-resistant hard surface production, high hardness stability, used in hot forging dies, stamping dies, rolling dies, trimming dies, car dies, hot rolling wheels, Hard surface of wear-resistant parts.

CMC-E60A welding electrode HRC 60 ~ 62 2.6, 3.2

High hardness stability, resistance to medium and high temperature wear. It is suitable for the production of hard surfaces of medium carbon steel and low alloy steel, repair of wear-resistant cutting tools, car molds, hot forging and cold forging notch dies.

CMC-E30N electrode with high tension and high toughness 2.6, 3.2

The joint of high hardness steel, the steel mold base is fixed, the hard surface of the cast steel mold is used as the base buffer layer, and the crack is welded.

CMC-E61N welding electrode 3.2 * 350mm

Suitable for welding all kinds of cast iron, alloy cast iron, steel and cast iron, nickel and its alloys, etc., or welding of water resistant die castings.

CMC-E7W electrode HRC 53 55 3.2, 4.0

It is suitable for the cutting edge welding and damage surfacing of air-cooled steel (ICD5) or cast steel, especially for cutting edges, punching and flanging parts of automotive sheet metal molds, and cutting angles and edges of light industrial sheet metal stamping dies. For the production of cutting tools, overlay welding can also be used as the cutting edge. It can also be applied to the hard surface making of wear-resistant parts.

CMC-E47N welding electrode HRC 44 50 3.2 * 350mm

Welding rods that can be directly applied to cast iron are very convenient to use in the knife edge and extension parts of cast iron molds.

CMC-EH10 electrode HRC 46 52 3.2, 4.0

It is suitable for the production, repair and surface reconstruction of medium and large-scale hot forging dies. Because the chromium content is reduced, and the alloy composition of molybdenum, tungsten, and vanadium is increased, a good balance between high-temperature wear and toughness is formed, and the service life of hot work molds with large cross-sectional areas is greatly improved. Widely used in the production of medium and large-scale hot hammer forging dies, hot forging dies, thermogravity die-casting dies, and hard surfaces of wear-resistant parts.

CMC-EH13 electrode HRC 55 58 2.4, 3.2

It is suitable for damage-resistant welding of hot working tools, especially hot-cutting tools, hot-shear tools, and hot-planing tools. For the production of shear processing tools, it can also be used as a shear edge on low alloy or ordinary steel by welding.

According to different situations, there are three classification methods for welding electrodes: according to the purpose of the electrode, by the main chemical composition of the coating, and by the characteristics of the molten slag after the coating is melted.

According to the purpose of the electrode, the electrode can be divided into: structural steel electrode, heat-resistant steel electrode,

The electrode consists of the electrode core and the coating. One of the roles of the electrode core is to conduct electricity as an electrode. At the same time, it is also the main material for forming the weld metal. Therefore, the quality of the electrode core directly affects the performance of the weld. The high-quality steel welding carbon steel electrode core is usually 0.08% C low-carbon steel. The most widely used are H08 and H08A, whose carbon content and sulfur and phosphorus harmful impurities have severe restrictions on the diameter of commonly used electrodes ( That is, the diameter of the electrode core is 2.5 to 6 mm and the length is 350 to 450 mm. Although the electrode is generally resistant to external damage, it cannot be ignored that it is easily damaged due to poor storage. The electrode is a ceramic product. He cannot be as impact resistant as a steel core, so he cannot drop him during loading and unloading. Welding electrodes packed in cartons cannot be carried by hooks. Some types of electrodes, such as alkaline electrode coatings with special drying requirements, should be handled more carefully than normal electrodes. In general, the welding electrodes are packaged in plastic bags and cartons. In order to prevent moisture absorption, the electrodes must not be disassembled before use, and they should be dismantled as far as possible. If possible, the remaining electrodes are sealed after welding. . Acidic electrodes are not sensitive to moisture, while organic rutile electrodes allow higher moisture content. Therefore, it should be dried at 70-150 ° for one hour according to the specific conditions of moisture. The storage time is short and the packaging is good. Generally, it is not necessary to dry before use. The alkaline low hydrogen electrode must be dried before use to reduce the hydrogen content of the electrode and prevent defects such as pores and cracks. The general drying temperature is 350 ° C for one hour. Do not put the electrode in a high-temperature furnace or cool it suddenly to prevent the coating from cracking. For special requirements for hydrogen content, the drying temperature should be increased to 400-500 ° C for one to two hours. The dried alkaline electrode is best stored in another low temperature drying box controlled at 50-100 ° C, and taken as needed. When drying the electrodes, each layer of electrodes should not be stacked too thick (usually 1-3 layers) to avoid uneven heating and moisture of the electrodes during drying. When operating in the open air, the electrodes must be properly stored overnight, not allowed to be stored in the open air. They should be stored in a low temperature box at constant temperature, otherwise they must be dried again the next day.

The so-called "overdue" does not mean that the storage time exceeds a certain time limit, but that the quality has changed to varying degrees (deterioration). Various types of welding electrodes are stored for a long time, and sometimes white crystals (hair) are found on the surface of the electrode. This is usually caused by water glass. These crystals are not harmful, which means that the electrode is stored for a long time and is wet. Technological tests should be performed on electrodes that have been stored for many years, and the electrodes should be dried at the specified temperature. During welding, no abnormal changes were found in the technical properties of the electrode. For example, if the coating has fallen off and there are defects such as pores and cracks, the mechanical properties of the electrode are generally guaranteed. Because the electrode has a slight rust stain on the wet core, it basically does not affect the performance, but if high welding quality is required, it should not be used. Welding rods are severely rusted and can be degraded or used for general component welding as appropriate. It is best to test its mechanical properties according to national standards and then determine its scope of use. If the welding coating contains a large amount of iron powder, the relative humidity is high and the storage time is long, the welding rod is seriously wet, and even the coating has rust phenomenon. Although such a welding rod is dried, it still produces high porosity or high hydrogen content during welding , And therefore also scrapped. Improved packaging is required to prevent the electrodes from absorbing moisture, which must be properly stored during storage. Various types of welding rods are seriously deteriorated, and the coating has been severely peeled off. This batch of welding rods should be scrapped.

Welding electrode manufacturing from raw materials into the factory to the electrode factory mainly through five processes: welding core processing, preparation of coating materials, electrode coating: drying, packaging. The main harmful substances produced in each process are as follows:

(1) Wire drawing process in welding core processing: peeling mechanical derusting to produce iron oxide dust. Calcium hydroxide dust is generated at the lubricant box of the drawing die of the drawing machine. When there is a pickling process. The sulfuric acid mist is generated in the pickling tank, and the calcium hydroxide dust is generated when it is stained in the ash tank and dried.

(2) Preparation process of medicinal material: feeding, sieving powder, weighing, stirring operation point. Generates mixed dust of various materials, mainly silicon dust and manganese dust. The content of free silica is as high as 19.6%. The content of manganese dust is up to 4.35mg.

(3) Welding, drying and packaging processes of the electrode: iron powder is produced by the wire feed bucket and wire feed wheel, and the dust coating machine head, grinding head grinding tail, packaging and waste electrode recycling generate a mixture mainly composed of silicon dust and manganese dust. Sexual dust.

GB30188-2013 scope of application and content This standard is a full text mandatory standard. The main content of the standard is mandatory clauses. This standard was developed on the basis of a large amount of data collection and detailed enterprise research and testing. Although the main content is mandatory. However, due to the consideration of the current situation and development of welding electrode manufacturing enterprises in China. The technical measures required in the standard are currently available to most enterprises. This standard is applicable to the design, transformation and occupational health management of dust and gas protection for all welding rod manufacturers. It is also applicable to the supervision of relevant departments on the harm of dust and poisons during the production process of welding electrode manufacturing enterprises.

In terms of content structure, this standard is divided into ten chapters, and the main content is introduced as follows:

Chapter 1: Scope. This chapter first clarifies the main content of this standard. Defines the scope of application of this standard.

Chapter 2: Normative references. In accordance with the requirements of "Guidelines for Standardization Work Part 1: Structure and Compilation of Standards", this section introduces the standards involved and cited in this standard, as well as descriptions of the referenced standards.

Chapter 3: Terms and Definitions. This standard only defines the words involved in the standard that need to be further clarified so as not to cause ambiguity, and does not define well-known terms.

Chapter 4: General. This chapter mainly puts forward requirements from the general and most basic aspects. It mainly includes the goals that dust and poison hazard management should achieve, the "three simultaneous" management of dust and anti-virus equipment and facilities, and capital investment in dust and anti-virus work. The content of this part is the basis for the dust and gas prevention work of welding electrode manufacturers.

Chapter 5: Plant site, plant area and plant. This chapter puts forward specific dust and gas protection regulations for site selection, plant area and plant layout. Enterprise site selection. About the sanitary protection distance between the welding electrode manufacturing enterprise and the protected object. This standard refers to the health protection distance standards of some similar manufacturing enterprises that emit dust. From the comparison of the amount of dust emitted, the degree of harm to the human body, and the characteristics of dust toxicity, etc., the sanitary protection distance of the welding electrode manufacturing enterprise is determined. Compared with cement plants and lime plants, the amount of dust generated by the electrode plant is relatively small, and the occupational hazards of the dust are similar. Therefore, it is determined that the health protection distance of the electrode plant is slightly lower than that of the cement plant and higher than that of the lime plant Sanitary protection distance.

Chapter 6: Process technology requirements for dust and gas protection. This chapter puts forward from the technical aspects of the electrode manufacturing enterprises should implement mechanization and automation, wire drawing process should eliminate pickling, improve the electrode coating formula and other requirements.

Chapter 7: Confined dust source and ventilation dust removal. This chapter puts forward relevant requirements from three aspects: dust source containment, ventilation and dust removal, ventilation and dust removal system operation, and maintenance. It mainly specifies the parts where the dust source should be sealed in the entire welding electrode production process: it is stipulated that a centralized dust removal system should be set for the automatic powder matching process. The exhaust hood controls the dust absorption method of the dust absorption point or the stand-alone dust removal unit. For places or links such as the pressure coater, grinding head and tail grinding device, and waste powder recovery, it is required to apply centralized dust removal or stand-alone dust removal unit dust removal: A separate operation room should be provided for manual powder distribution. The powder distribution room should adopt the comprehensive ventilation and dust removal method of the upper and lower rows. This standard further stipulates that the mechanical ventilation workshop should maintain a certain negative pressure, and at the same time ensure the wind and heat balance of the workshop. You should nt just refuse. The provision is mainly due to the fact that enterprises used to install ventilation and dust removal systems in the past. In order to reduce capital investment, the installation of air supply systems is often cancelled. As a result, the exhaust system is turned on. The negative pressure in the workshop is too high and the temperature is too low to guarantee normal production. As a result, the entire ventilation and dust removal system was deactivated.

Chapter 8: Personal Protection. This chapter puts forward requirements for the personal protection measures and the selection, equipment and management of labor protection products for welding electrode manufacturers. In accordance with the documentary spirit of the State Administration of Work Safety Order No. 1 "Provisions on the Supervision and Management of Labor Protection Articles" and the Safety Supervision General Planning Character [2005] 149 "Detailed Implementation Rules for the Safety Signs of Special Labor Protection Articles", this standard stipulates Manufacturers should purchase and use special labor protection articles with safety signs. "

Chapter 9: Management. This chapter puts forward requirements from the aspects of establishing and perfecting a dust and anti-virus work management system, occupational health management staffing, knowledge education and training of employees on dust prevention, and workshop dust concentration monitoring.

Chapter 10: Occupational health surveillance. This chapter conducts occupational health checks on workers exposed to dust and hazards. Regulations have also been made in establishing occupational health surveillance files ^[1] .