中文
according to different situations, welding, there are three classifications: Classification by use of electrode, by the skin of the main chemical ingredient drug classification of drugs according to the characteristics of the skin melted slag classification.
According to the use of welding, Carbon Steel Welding Electrode can be divided into: structural steel welding rod, heat-resistant steel electrode, stainless steel welding rod, welding electrodes, low temperature steel electrodes, cast iron welding rod, nickel and nickel alloy electrodes, copper and copper alloy rod, aluminum and aluminum alloys and special purpose welding rod.
If the drug under the skin electrodes to the classification of the main chemical components, welding can be divided into: titania type electrode, titanium calcium type electrode, ilmenite-type electrode, iron oxide-based electrodes, cellulose type electrode, low hydrogen type electrode , graphite electrode and the type of base electrode.
If the drug under the skin electrode melting, the slag characteristics to classify, welding can be divided into acidic and basic welding electrodes. 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.
An electrode type according to the mechanical properties of deposited metal, drug skin type, welding position and welding current of each type of
Type 2 electrodes prepared as follows: the letter E, said electrodes; first two numbers indicate the minimum tensile strength of deposited metal; the third digit position of the welding electrode, said welding to 1 .0 and suitable for all position welding (flat, Li, Yang, Wang), "2" for flat welding electrodes and Welding Electrodes and flat, "4" stand down, said electrode for welding; third and fourth digit combinations, said welding current skin type and drug type. Added in the fourth digit after the "R" means resistance to moisture absorption electrode; additional "M" indicates resistance to moisture absorption and mechanical properties of the electrode with special requirements; additional "-1" indicates that the impact of special provisions of the electrode performance.
D502 valve surfacing electrode line GBEDCr-A1-03
Description: D502 is titanium calcium type coating of 1Cr13 valve surfacing electrode can be both AC and DC Welding Electrodes process is good. Weld metal is high 1Cr13 semi-ferritic chromium steel. Cladding layer with air quenching characteristics, generally do not need to heat treatment, hardness uniformity, can be annealed at 750-800 ℃ soften when heated to 900-1000 ℃ air-cooled or oil quenched, can be re-hardened.
Uses: This is a versatile surfacing welding rod for welding temperature carbon steel at 450 ℃ or below the shaft and alloy steel valves.
D507 valve surfacing electrode line GBEDCr-A1-15
Description: D507 is a low hydrogen sodium type coating for welding electrodes 1Cr13 valves, DC reverse. Weld metal is high 1Cr13 semi-ferritic chromium steel. Cladding layer with air quenching characteristics, generally do not need to heat treatment, hardness uniformity, can be annealed at 750-800 ℃ soften when heated to 900-1000 ℃ air-cooled or oil quenched, can be re-hardened.
Uses: This is a versatile surfacing welding rod for welding temperature carbon steel at 450 ℃ or below the shaft and alloy steel valves.
D507Mo valve surfacing electrode line GBEDCr-A2-15
Description: D507Mo is a low hydrogen sodium type coating for welding electrode 1Cr13 valve type. Weld metal is high 1Cr13 semi-ferritic chromium steel. Cladding layer with air quenching characteristics of deposited metal with a high-temperature hardness, good thermal stability, erosion resistance. If used in conjunction with the D577 electrode can get a good anti-abrasion performance. Welding process is simple, no warm-up before welding, after welding without heat treatment, using DC reverse.
Uses: used in the welding temperature below 510 ℃ temperature and high pressure in the valve sealing surface. Valve sealing surface of the electrode should be used in conjunction with the D577 electrode (with the valve seat with the above two electrodes, respectively). D507MoNb valve surfacing electrode line GBEDCr-A1-15
Description: D507MoNb is a low hydrogen sodium type coating of 1Cr13 valve surfacing electrode with a DC reverse, because the amount of drug added to the skin of Mo, Nb and other elements to strengthen the stability, so deposited metal has good resistance to oxidation and anti-cracking performance.
Use: temperature at 450 ℃ below, the low pressure valve sealing surface of the cladding.
D512 valve surfacing electrode line GBEDCr-B-03
Description: D512 is titanium calcium type coating for Carbon Steel Electrode electrode 2Cr13 valves, AC and DC welding process is good. Deposited metal is 2Cr13 martensitic high chromium steel. Cladding layer with air quenching properties, usually without heat treatment, hardness uniformity, annealing at 750-800 ℃ soften when heated to 950-1000 ℃ air cooling or oil quenching can be re-hardened.
Uses: D512 is a versatile surfacing electrode surface, hard surfacing more than the D502, more wearable, more difficult process for welding carbon steel or low alloy steel shaft, with superheated steam valve, mixer propeller, screw conveyor blades.
D516MA valve surfacing electrode line GBEDCrMn-A-16
Description: D516MA is a low hydrogen potassium type coating of high-chromium-manganese steel welding electrodes, welding metal layer has good abrasion resistance, heat resistance, corrosion resistance and thermal crack resistance, welding process is simple, no warm-up before welding, without heat treatment after welding, cladding layer can be machined.
Uses: used in the welding temperature below 450 ℃ by water, steam, oil and media under the action of the components, such as the 25 steel, high pressure valve sealing surface.
D517 valve surfacing electrode line GBEDCr-B-15
Description: D517 is a low hydrogen sodium type coating of 2Cr13 valve surfacing electrode with a DC reverse. Deposited metal is 2Cr13 martensitic high chromium steel. Cladding layer with air quenching properties, usually without heat treatment, hardness uniformity, annealing at 750-800 ℃ soften when heated to 950-1000 ℃ air cooling or oil quenching can be re-hardened.
Uses: D517 is a versatile surfacing electrode surface, hard surfacing more than the D502, more wearable, more difficult process for welding carbon steel or low alloy steel shaft, with superheated steam valve, mixer propeller, screw conveyor blades.
D547 valve surfacing electrode line GBEDCrNi-A-15
Description: D547 is a low hydrogen sodium type coating, steel core CrNiSi valve surfacing electrode with a DC reverse. Rely on silicon metal surfacing intensive to get a certain ferrite austenite, so that it has good resistance to abrasion, corrosion, anti-oxidation properties.
Uses: 570 ℃ for welding high-pressure boiler plants operating below the valve sealing surface installations, and other seal parts.
D547Mo valve surfacing electrode line GBEDCrNi-B-15
Description: D547Mo is a low hydrogen sodium type coating of CrNiSiMo valve surfacing welding rod. DC reverse. Weld metal has good high temperature abrasion resistance, anti-erosion properties, a higher temperature hardness, good thermal stability and fatigue resistance. Deposited metal aging strengthening effect is remarkable, as the aging time increases, the hardness and abrasion resistance to further improve performance.
Uses: for temperature below 600 ℃ high-pressure valve sealing surface of the cladding.
D557 valve surfacing electrode line GBEDCrNi-C-15
Description: D557 is a low hydrogen sodium type coating of CrNiSi valve surfacing welding rod, welding metal to rely on a large number of silicon intensive, get austenite + ferrite, with the aging time increased, hardness and abrasion resistance further improve performance, deposited metal has good corrosion resistance, oxidation resistance and corrosion resistance, DC reverse.
Uses: for temperature below 600 ℃ high-pressure valve sealing surface of the cladding.
D577 valve surfacing electrode line GBEDCrMn-C-15
Description: D577 is a low hydrogen sodium type coating, the Cr-Mn alloy valve core welding electrodes. DC reverse, deposited metal for high-Cr-Mn austenitic steels, it is a significant effect of work hardening, has a good anti-abrasion performance, in a certain temperature and hardness, good thermal stability, such as cooperation with D507Mo use, access to good anti-abrasion performance, good crack resistance of the electrodes, welding process is simple, rod from time to warm up after welding without heat treatment, welding metal cutting performance is good.
Use: welding temperature at 510 ℃ in temperature and high pressure below the valve sealing surface, such as the valve in conjunction with D507Mo life higher.
Welding electrodes for use valve
Executive GB984-2001 standard
Surfacing in the workpiece surface or edge of the deposited layer of wear, corrosion, heat and other properties of the metal layer of the welding process. Parts for repair and improve the life of the rational use of materials, improve product performance, reduce costs have significant economic benefits.
Surfacing work and working conditions are very complicated, different welding requirements must be based on the appropriate choice of electrode. Different surfacing electrode to the workpiece and the welding of different techniques, in order to obtain satisfactory welding results. Surfacing in the most commonly encountered problem is cracking, prevent cracking of the main methods are:
1 warm-up before welding, the control layer temperature, slow cooling after welding.
(2) stress relief heat treatment after welding.
3 to avoid cracking when the multi-layer welding, welding with low hydrogen electrodes.
4 If necessary, weld overlay cladding and buffer layer between the base metal (low carbon equivalent, high toughness electrodes).
