Welding regarding cracks in the welds connecting the shaft and the impeller
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This post was last edited by A’Dai A’Mu on 2012-3-31 at 14:30. Regarding cracks in the welds at the connection point between the shaft and the impeller: rewelding is required, with the shaft being made of 60 carbon steel and the impeller made of cast duplex stainless steel. Analysis: Tungsten inert gas welding can be used to weld duplex steel without preheating, whereas high-carbon steel, with its higher hardness and carbon content, is prone to defects such as hot cracks and cold cracks during welding. . . Current applications of room-temperature cold welding techniques include pulses (arc welding, laser welding, etc.), and it is said that such welding results in no temperature rise, no stress concentration, and no cracks. Dear sea friends, please consider how to agree on the welding repair plan and process A detailed analysis of the advantages and disadvantages of TIG welding and cold welding! After thorough consideration and preparation, a welding plan has been developed to carry out pulse welding (without temperature rise, without stress, and without cracks).
For the welding repair using cold welding technology, drill (chisel) the leaky area to a depth of 5–6 mm, remove any sand inclusions and burrs thoroughly. No preheating is required; cold welding can be carried out directly. Someone else told me this; I’m not sure though
To analyze the cause of the cracks, was it caused by the cooling process after welding or by torsional forces during use?
Where did the crack occur? Was it in an area that had been welded before? If it was an original TIG weld crack, it’s likely difficult to repair it using TIG welding again. If it is a material crack, TIG welding should be sufficient to repair it. Laser welding does offer high quality, but it’s not suitable for your situation.
The maintenance unit suggested using tungsten inert gas welding or arc welding with alloy steel wire – there’s no problem with that, but I’m not sure if it will work