Weld penetration problem in the atmospheric pressure tank of ammonium chloride in catalyst units
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The medium contained within a constant-pressure device in the catalyst installation is ammonium chloride, and the material of this device is 304 stainless steel. After operating for some time, perforations were detected in the circumferential welds between the head and the cylinder. The device was shut down for repair, and cracks appeared in the area that was repaired (cracks were also found on the cylinder itself). I would like to ask the experts what could be the cause of this?
Is it because the materials you chose don’t match?
There are cracks in the equipment cylinder; it is estimated that the material chosen was inappropriate, or there is an issue with the cylinder material； There are also problems with the welds; intergranular corrosion occurs (due to chloride ions)
Chloride ions cause stress corrosion in stainless steel; the material used for the cylinder body was not selected appropriately – duplex steel or other more advanced materials should be used instead. Weld seam penetration is also caused by welding stresses.
Hehe, which organization is responsible for selecting the materials? Stainless steel is still required in the presence of large amounts of chloride ions.