Repair method of carbon steel pump equipment parts
There are many types of steel materials used in chemical pump parts, and their weldability varies greatly. As far as carbon steel is concerned, the higher the carbon content in the steel, the greater the tendency of cracks during welding, the worse the weldability, and the stricter the requirements for repair welding technology.
1 Repair welding of low carbon steel parts
Carbon steel with w(C)≤0.25% is low carbon steel with good weldability. Generally, there is no need to take special technological measures during repair welding, and satisfactory results can be obtained by using general J422 electrodes. Only in special cases, such as the rigidity of the part is very large, the restraint degree during welding is very large, or the repair welding at low temperature may cause cracks. At this time, attention should be paid to the selection of high-quality welding rods to enhance the crack resistance of the weld metal. At the same time, reasonable welding process to reduce welding stress.
2 Repair welding of medium and high carbon steel parts
The carbon steel with w(C) of 0.25%~0.50% is medium carbon steel, and the w(C) of high carbon steel is above 0.50%. With the increase of carbon content in steel, the sensitivity of welded joints to cracks also increases accordingly. The cracks mainly include hot cracks in the weld, cold cracks caused by the low plasticity and hard structure due to the fast cooling rate in the heat affected zone, and hydrogen-induced cracks mainly caused by hydrogen infiltration at the root of the weld.
pump parts Butterfly valve