What type of corrosion is this?
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The surface has cracks, and the inside is empty when cut open
What materials, and under what operating conditions does corrosion occur? How long does it take?
Could it be some strange, knife-like corrosion? !
In a hydrogen-rich environment, hydrogen embrittlement may occur
Cyclohexene, over 100 degrees, stainless steel material
It took 4 years; the corrosion occurred in the thermal stress area of the weld
It’s been in use for four years; it should be fine, and it’s time for maintenance roughly
Analysis of the causes of weld corrosion in stainless steel equipment: Local corrosion refers to a form of corrosion in which, under the action of corrosive agents, the matrix of stainless steel is rapidly corroded in specific areas (mainly the welding heat-affected zone). This type of corrosion poses a serious threat to equipment; therefore, stainless steel must be selected properly based on the conditions of the medium. The main types of local corrosion include intergranular corrosion, pitting corrosion, stress corrosion, etc. These corruptions often cause cracks in the welds, and the common method for on-site repair is to grind away the weld area and then weld it again. This re-welding process further deteriorates the material in the heat-affected zone of the weld, making it more susceptible to corrosion and damage, resulting in a situation where the condition worsens with each attempt at repair. Therefore, post-weld treatment is an essential process.
There is a high likelihood of stress exceeding the limits; it is recommended to conduct a stress analysis on the pipeline.