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Cobalt Alloy Electrode Welding Knowledge

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    5 декабря 2018 г., 12:18:25 MSK

    Cobalt Alloy Electrode Low Temperature Steel Structure Welding Knowledge.

    1. Cobalt alloy electrode: In low temperature environment, low-hydrogen or ultra-low-hydrogen welding consumables should be selected as much as possible, and baking and heat preservation measures should be strictly applied to the welding consumables;
    2. Pre-weld protection: Shielding in the welding steel structure working area, so that the welding area forms a relatively closed space, reducing heat loss. If the protective shed is unconditionally set, other effective measures should be taken to protect the welding area; during gas shielded welding, Welding gas cylinders should also take corresponding measures to keep warm;
    3. Preheating and interlaminar temperature: The preheating temperature in a low temperature environment should be slightly higher than the preheating temperature of the welded steel structure of the Cobalt Chrome Alloy electrode at normal temperature, and the heating zone is greater than or equal to twice the thickness of the steel plate and not less than 100 in each direction of the component welding zone. In the base metal in the range of millimeters, the temperature between the welding layers is not lower than the preheating temperature or the minimum temperature specified by the standard (JGJ81-2002) is 20 °C (both high values);
    4. Increase the heat input during tack welding: appropriately increase the heat input of the tack weld, increase the cross section and length of the weld, and use the same preheating conditions as the formal weld, do not arc on the base metal outside the groove, and extinguish the arc When the crater must be filled, it can effectively reduce the shrinkage crack caused by the positioning welding;
    5. Cobalt alloy electrode welding process: use narrow swing, multi-layer multi-pass welding, and strictly control the interlayer temperature;
    6. Cobalt alloy welding rod after welding heat and heat preservation: After welding, the welded joint is post-heat-heat-treated, which can effectively control t8/5, which is conducive to the diffusion of hydrogen gas and prevent cold cracks caused by excessively fast cooling rate. After the hot temperature, the preheating temperature can also be appropriately lowered.

    In short, before the construction of the low-temperature welded steel structure of the Cobalt Alloy Bar electrode steel structure, the welding process qualification test must be done according to the actual situation. If necessary, the low-temperature weldability test should be carried out for the specific steel grade, and a suitable welding procedure guide should be made to guide the actual situation. welding. In the low temperature environment, the adverse effects on the welder's operation should also be given enough attention. The general ambient temperature should not be lower than -15 °C.