Corrosion issues
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The ammonia pipelines are severely corroded; the new pipelines started leaking within less than a year of being installed. The same is true for the equipment used to store ammonia. Tungsten inert gas welding is used as the base layer during welding, with electric welding used for filling in the gaps. Why do they start leaking so quickly?
Is it a leak from the weld or somewhere else? Was heat treatment performed after welding?
The weld is leaky; no heat treatment was performed.
That could be stress corrosion cracking; the ammonia line should have undergone post-weld heat treatment to relieve stresses
The equipment is made of Q235B material, while the pipes are made of 10# steel.
Heat treatment is required after welding to relieve stress
If it is welding, heat treatment is required after welding
If it is welding, heat treatment is required after welding
Ammonia solution, especially recycled ammonia solution, has a strong penetrating corrosion effect; it primarily causes cracks in the heat-affected zone of the welds. This is a form of stress corrosion. To address this issue, it is advisable to use a hammer to tap each layer/pass during welding. After welding is complete and no defects are detected, post-weld heat treatment should be carried out to relieve stresses, which yields good results.