According to the nature of different drug skin electrode, welding electrodes can be divided into acidic and alkaline electrode into two categories. Skin contains large amounts of acidic drug oxide (TiO2, SiO2, etc.) of the electrode is called acid electrode. Skin contains large amounts of drugs alkaline oxide (CaO, Na2O, etc.) as basic electrodes. Acid electrode to AC and DC welding performance is better, but the mechanical properties of the weld, especially in poor impact toughness, suitable for general low-carbon steel and low strength low-alloy structural steel welding is the most wide electrode. Alkaline electrode desulfurization, dephosphorization ability, the role of drug skin with dehydroepiandrosterone. Welded joints is very low hydrogen content, it is also known as low-hydrogen electrodes. Alkaline electrode welds with good crack resistance and mechanical properties, but the process performance is poor, usually with a DC welding, mainly for important structures (such as boilers, pressure vessels and alloy steel, etc.) welding.
Recognition electrode is acidic or alkaline?
See welding grades. Structural steel, for example: grades, the preparation method. Knot XXX, became structural steel welding rod, the first three numbers represent the type of drug skin, welding current requirements, the number 1 and 2: on behalf of the weld metal tensile strength. Acidic drug electrode main component of skin acidic oxides such as silica, titanium dioxide, iron oxide and so on. Basic electrode for the main component of skin medicine alkaline oxides, such as marble, fluorite.
Alkaline better crack resistance welding, the weld rod is not clean or clean-up is not easy drying air hole.
Say that crack, and income from the arc at the arc to produce crater cracks, and if the weld cracks at the regular shows you do not match the base metal and welding rod
Welding can be divided into several categories: carbon steel electrode, stainless steel welding rod, Welding Electrodes, cast iron welding, silver welding, heat-resistant steel electrodes, low temperature steel electrodes, copper electrodes, aluminum electrodes, cobalt-based electrodes, nickel electrodes, cellulose pipe welding, underwater welding, cutting and welding and so on. The main specifications are: 2.5 3.2 4.0 5.0mm
What types of electrode wear?
D-667-type high-chromium cast iron wear-resistant welding rod: This rod can be surfacing in the low, medium carbon steel, low alloy steel, high manganese steel and cast iron parts surface. Can withstand high impact wear, weld hardness HRC ≥ 55-65. 500 ℃ high temperature in the following with good resistance to abrasion, corrosion and cavitation capability. Generally increase the life of 3-8 times the weldment. This can be multi-electrode welding, welding layer 3 in order to achieve the best results (because the basic point is surfacing electrode composition, base metal composition rarely) the total thickness of surfacing not more than 1 cm is appropriate. For welding high temperature operating conditions of wear parts (such as: ring fired furnace discharge plow plow better). Welding operation by the strong impact of wear parts (such as: mining and cement crusher tooth plate) and D-266 model with the use of high manganese steel surfacing economy better. The electrode in use, according to the instructions, before the welding electrode drying, preheating welding pieces of clean, slow cooling after welding. D-698 graphite type coating for welding electrodes, AC and DC. For mineral soil sediment and rock crushing machinery wear parts of the welding strong. Deposited metal hardness HRC ≥ 60. D-707 wear-resistant tungsten carbide surfacing electrode: carbon steel, low hydrogen sodium type core tungsten electrode, the DC reverse. Suitable for concrete mixer blades, bulldozers, high-speed sand box, dredging machine blades. Deposited metal hardness HRC ≥ 63-75. D802 D812: cobalt-based electrode valves: cast cobalt-chromium-tungsten alloy core welding electrode welding, legal drugs into the skin by dipping the electrode surfacing, should adopt the DC reverse. Deposited metal at 1000 ℃ still have good wear resistance and corrosion resistance. Application: Suitable for high temperature and pressure valves, high pressure pump shaft sleeve and inner sleeve, and chemical fiber equipment and other parts of the mouth of the cut edge of surfacing. Surfacing hardness HRC ≥ 40 Note: 1, before welding electrodes shall be subject to about 200 ℃ bake 1 hour or more re-applied solder. 2, as far as possible when short arc welding, and Welding Rods work vertical. 3, according to the size of the work and the type of base material shall be 300 ~ 600 ℃ preheating. Should adopt the low current short-arc welding. 4, after welding should be tempered at 600 ~ 700 ℃ 1 hour after working in relief will be immediately placed in cold or dry and hot sand box or kelp in the slow cooling to avoid cracking. 5, the surfacing shall be coarse, if found defective, the above steps welding and slow cooling. Cobalt welding wire Description: welding D802 cast cobalt-chromium-tungsten alloy wire core welding wire welding, welding core by dipping into the legal system surfacing wire, deposited metal at 1000 ℃ and still have good wear resistance and corrosion resistance. Application: Suitable for high temperature and pressure valves, high pressure pump shaft sleeve and inner sleeve, and chemical fiber equipment and other parts of the mouth of the cut edge of surfacing. Weld metal chemical composition (%) C 1.0 ~ 1.7 Cr 26.0 ~ 32.0 W 7.0 ~ 10.0 Mn ≤ 2.0 Si ≤ 2.0 Fe ≤ 3.0 Co margin surfacing hardness HRC ≥ 40 specifications φmm 2.5 3.0 D968: graphite type coating of welding electrode, AC and DC. Deposited metal hardness HRC: 61 ~ 66. YM602W-Cr-B: graphite type coating, both AC and DC, for carbon steel, cast steel, manganese steel base metal coated with solder. Welding layers of high strength against the external play the role of wear, such as strong on a variety of devices easy to wear pieces. Deposited metal hardness HRC: 61 ~ 66. D-708: Tungsten welding electrode wear: wear-resistant alloys with a variety of DC welding. Strong rock for surfacing wear-resistant mechanical parts such as fan blades, concrete mixer blade, pink stone hammer, charcoal machine screw and other wear parts for surface repair. Deposited metal hardness HRC ≥ 70.
Coated with a drug for the skin known as arc welding with melting electrode section, referred to as electrodes. Drug by the welding electrode core and skin (coating) composition. Arc welding is usually chamfered end, part of drug skin is removed, exposing the core weld ends, and some arc welding arc-side coated with agents that arc easier. Drugs near the clamp on the skin side of the printed electrode grades. Electrode was covered medicine bag welding the metal core, said core. Electrode arc welding, the welding between the core and arc welding pieces and melt into the weld filler metal. Welding core both electrodes, is filled with metal. According to national standards GB/1495.7-1999 welded wire and GB/17854-1999 welded stainless steel wire requirement for a dedicated core welding wire (known as wire) into carbon steel, low alloy three types of structural steel and stainless steel. Welding core components will directly affect the weld metal composition and performance, all kinds of Welding Electrodes used in the core (wire) Table 2-1.
Table 2-1 welding of various types of welding used in the core Electrode types used in welding core Low carbon steel electrode Low-alloy high strength steel welding rod Heat-resistant low-alloy steel electrode Stainless Steel Electrodes Electrode surfacing Cast iron Welding Rods
Non-ferrous welding electrode low carbon steel core (H08A, etc.) Low-carbon steel or low alloy steel welding core Low-carbon steel or low alloy steel welding core Stainless steel or mild steel welding core Low-carbon steel or alloy steel welding core Low-carbon steel, cast iron, non alloy welding core Non-ferrous metal welding core
Solder coating on the surface of the active ingredients as the core drug skin, also known as coating. Drug skin electrode is ore powder, iron alloy powder, organic raw materials and chemical products such as prepared by a certain percentage of the core after the pressure applied to the solder coating on the surface layer. Its role is to: 1, the mechanical protection of the skin electrode melting or decomposition of drugs to produce gas and slag, the absence of air, to prevent the metal droplet and the bath in contact with air. The residue solidified slag shell covering the surface of the weld, the weld metal to prevent high temperature oxidation and nitriding, and slow down the weld metal cooling rate. 2, metallurgical processing and alloy to oxygen through the slag to sulfur, phosphorus removal, dehydrogenase and infiltration alloy welding metallurgical reaction, can remove unwanted elements, adding useful elements, the weld with good mechanical properties. 3, to improve the performance of drug skin welding arc can easily ignite and to ensure a stable continuous combustion; while reducing spatter and improve weld metal transfer and so on. 4, drug skin permeability alloy electrodes containing alloying elements in the transition to a molten bath, you can improve the performance of the weld metal.