D502 knife gate valve welding electrode conforms to GBEDCr-A1-03
    Description: D502 is a 1Cr13 type knife gate valve surfacing electrode with titanium calcium type coating. It can be used for AC and DC electric wedge gate valves. The welding process is good. The surfacing metal is 1Cr13 semi-ferrite high chromium steel. The surfacing layer has the characteristics of air quenching, generally does not require heat treatment, and the hardness is uniform. It can also be annealed and softened at 750-800 ° C. When heated to 900-1000 ° C, it can be hardened again after air cooling or oil quenching.
    Uses: This is a versatile electrode for surface surfacing welding. Wedge gate valves are used for surfacing welding of carbon steel or alloy steel shafts and knife gate valves with working temperature below 450 ℃.

    The welding electrode of D507 knife gate valve conforms to GBEDCr-A1-15
    Description: D507 is a 1Cr13 knife gate valve surfacing electrode with low-hydrogen sodium type coating, which uses DC reverse connection. The surfacing metal is 1Cr13 semi-ferrite high chromium steel. The surfacing layer has the characteristics of air quenching, generally no heat treatment is required, and the hardness is uniform. It can also be annealed and softened at 750-800 ℃. The Z45T / W-10 hidden rod wedge gate valve is heated to 900-1000 ℃ after air cooling or oil quenching. , Can be hardened again.
    Uses: This is a versatile electrode for surface surfacing welding. It is used for surfacing welding carbon steel or alloy steel shafts and knife gate valves with working temperature below 450 ℃.

    D507Mo knife gate valve surfacing electrode conforms to GBEDCr-A2-15
    Description: D507Mo is a 1Cr13 knife gate valve surfacing electrode with low hydrogen sodium type coating. The surfacing metal is 1Cr13 semi-ferrite high chromium steel. The surfacing layer has the characteristics of air quenching, and the surfacing metal has high hardness at medium temperature, good thermal stability, and erosion resistance. For example, Z44T / W-10 parallel double gate valve can be used with D577 welding rod to obtain good anti-scratch performance. The surfacing process is simple, no preheating before welding, no heat treatment after welding, DC reverse connection.
    Uses: It is used for surfacing welding the sealing surface of medium temperature high pressure globe valve with working temperature below 510 ℃. The sealing surface of the gate valve should be used in conjunction with the D577 electrode (the above two electrodes are used for the valve seat and disc). D507MoNb knife gate valve welding electrode conforms to GBEDCr-A1-15
    Description: D507MoNb is a 1Cr13 type knife gate valve fire protection signal elastic seat sealing gate valve surfacing welding electrode for low-hydrogen sodium type coating. It adopts DC reverse connection. Because the proper amount of Mo, Nb and other strengthening and stabilizing elements are added to the coating, the welding The metal has good oxidation resistance and crack resistance.
    Uses: Used for surfacing welding of sealing surfaces of medium and low pressure knife gate valves with working temperature below 450 ℃.

    D512 knife gate valve welding electrode conforms to GBEDCr-B-03
    Description: D512 is a 2Cr13 type special signal elastic seat sealing gate valve for titanium calcium type coating. It is a surfacing welding electrode for AC and DC. The welding process is good. The surfacing metal is 2Cr13 martensitic high-chromium steel. The surfacing layer has the characteristics of air quenching, generally no heat treatment is required, and the hardness is uniform. It can be annealed and softened at 750-800 ° C, and can be hardened again when heated to 950-1000 ° C with air cooling or oil quenching.
    Uses: D512 is a versatile electrode for surface surfacing. The surfacing layer is harder, more wear-resistant than D502, and more difficult to process. It is used for surfacing carbon steel or low alloy steel shafts, valves for superheated steam, and mixers. Paddle, screw conveyor blade RRHX elastic seat sealing gate valve, etc.

    D516MA knife gate valve welding electrode conforms to GBEDCrMn-A-16
    Description: D516MA is a high-chromium manganese steel surfacing electrode with low hydrogen potassium type coating. The surfacing layer metal has good wear resistance, heat resistance, corrosion resistance and thermal crack resistance. The welding process is simple, and it is not preheated before welding. No heat treatment after welding, the surfacing layer can be cut.
    Uses: Used for surfacing welding RVEX electric elastic seat sealing gate valve temperature below 450 ℃ under the influence of water, steam, petroleum medium components, such as 25th cast steel, high and medium pressure knife gate valve sealing surface.

    D517 knife gate welding electrode conforms to GBEDCr-B-15
    Description: D517 is a 2Cr13 type knife gate valve surfacing electrode with low hydrogen sodium type coating, which adopts DC reverse connection. The surfacing metal is 2Cr13 martensitic high-chromium steel. The surfacing layer has the characteristics of air quenching, generally no heat treatment is required, and the hardness is uniform. It can be annealed and softened at 750-800 ℃. The dark rod elastic seat gate valve can be re-hardened when heated to 950-1000 ℃ by air cooling or oil quenching.
    Uses: D517 is a universal electrode for surface surfacing welding. The surfacing layer is harder, more wear-resistant and more difficult to process than D502. It is used for surfacing carbon steel or low alloy steel shafts, valves for superheated steam, and mixers. Paddle, screw conveyor blades, etc.

    D547 knife gate valve welding electrode conforms to GBEDCrNi-A-15
    Description: D547 is a low-hydrogen sodium type coating, alloy steel core CrNiSi type knife gate valve surfacing welding electrode, using DC reverse connection. The surfacing metal is strengthened by silicon to obtain austenite structure with certain ferrite, which makes it have good properties of anti-scratch, corrosion resistance and oxidation resistance.
    Uses: Used for surfacing welding of sealing surfaces and other sealing parts of knife gate valves of power plant high-pressure boilers operating below 570 ℃.

    D547Mo knife gate valve welding electrode conforms to GBEDCrNi-B-15
    Description: D547Mo is a CrNiSiMo knife gate valve surfacing electrode with low hydrogen sodium coating. Use DC reverse connection. The surfacing metal has good high-temperature anti-scratch, anti-erosion and other properties, has high high-temperature hardness, good thermal stability and fatigue resistance. The aging strengthening effect of surfacing welded stainless steel gate valve metal is remarkable. With the increase of aging time, the hardness and anti-scratch performance have been further improved.
    Uses: Used for surfacing welding of the sealing surface of high-pressure knife gate valve with working temperature lower than 600 ℃.

    D557 knife gate valve surfacing electrode conforms to GBEDCrNi-C-15
    Description: D557 is a CrNiSi type knife gate valve surfacing electrode with low-hydrogen sodium type coating. The surfacing metal is strengthened by a large amount of silicon to obtain austenite + ferrite structure. With the increase of aging time, the hardness and scratch resistance The performance has been further improved. The surfacing metal has good corrosion resistance, oxidation resistance and corrosion resistance, and adopts DC reverse connection.
    Uses: Used for surfacing welding of the sealing surface of high-pressure knife gate valve with working temperature lower than 600 ℃.

    D577 welding electrode for knife gate valve conforms to GBEDCrMn-C-15
    Description: D577 is a chromium-manganese type knife gate valve surfacing electrode with low hydrogen sodium type coating and alloy steel core. Using DC reverse connection, the surfacing metal is high chromium manganese austenitic steel, so the cold work hardening effect is remarkable, it has good anti-scratch performance, has a certain middle temperature hardness, and good thermal stability, such as with D507Mo Use, can get very good anti-scratch performance, the electrode has good crack resistance, simple surfacing process, the electrode can not be preheated, no heat treatment after welding, surfacing metal cutting performance is good.
    Uses: It is used to seal the sealing surface of medium temperature high pressure knife gate valve with working temperature below 510 ℃. If it is used with D507Mo in the gate valve, the service life is longer.

    Instructions for surfacing welding electrode of knife gate valve:
    Implementation of GB984-2001 standard
    Surfacing is a welding process of depositing a metal layer with wear resistance, corrosion resistance, heat resistance and other properties on the surface or edge of the workpiece. It has significant economic benefits for repairing and improving the service life of parts, using materials reasonably, improving product performance, and reducing costs.
    The surfacing work and working conditions are very complicated, and suitable electrodes must be selected according to different requirements during surfacing. Different workpieces and surfacing electrodes require different surfacing techniques to achieve satisfactory surfacing effects. The most common problem encountered in surfacing is cracking. The main methods to prevent cracking are:
    1. Preheat before welding, control the temperature between layers, and cool slowly after welding.
    2. Perform stress relief heat treatment after welding.
    3. To avoid cracking during multi-layer surfacing, use low-hydrogen surfacing electrode.
    4. When necessary, build-up welding transition layer between the build-up welding layer and the base metal (use a low carbon equivalent, high toughness electrode)