Analysis of the causes of cracks in the cladding layer of the extraction tower

Abstract Pressure class special equipment is essential to the operation of a petrochemical production plant. Any failure in this equipment can lead to disastrous consequences. Therefore, during maintenance, it is crucial for technicians to quickly identify equipment problems, analyze their causes, and address them promptly to ensure safe operation. This paper takes a phenol acetone plant (PA) extraction tower as an example, for the penetration test found in the cladding cracks, to carry out background investigation, macro-inspection, spectral analysis, hardness testing, ferrite testing, and metallurgical testing. After comprehensive analysis, it is believed that the surface crack of the cladding layer is caused by chloride stress corrosion cracking, which is caused by improper welding process in the manufacturing process, resulting in large residual stress and intergranular sensitization of 300 series stainless steel. At the same time, according to the actual situation of the site, opinions on disposal and suggestions for subsequent use are given, which provides a reference for the inspection and testing of similar equipment.