Why are stainless steel forgings more prone to rusting than bars
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Stainless steel forgings are forged using degreased round bars (which remove the black scale from the surface of the steel sheet). After forging, they undergo solution treatment, followed by polishing and shot blasting, and then acid washing and passivation. After shaping, the stainless steel bars are solubilized, shot blasted, and pickled. The above is the status of the materials we use; after they arrive, they are machined, then ultrasonically cleaned, assembled, and shipped. However, it was found during customer use that the product was rusting, with the forgings being particularly severely affected by rust. Does anyone know why? Please help analyze it, thanks!
First, what is stainless steel? Secondly, what is the user’s application environment like?
Improper control of the forging heating time or cooling time can affect the corrosion resistance and mechanical properties of stainless steel.
Hello, it’s not just our products that are encountering this issue; other companies’ products installed on site also face the same problem. Additionally, these products are shipped by sea, and during transportation they are left in a nearly exposed state. Could you help analyze whether this is possible? That is, the forging process might cause element segregation. When taking spectra using electrical discharge machining, it is required to remove the surface layer first in order to obtain accurate spectra; otherwise, the chemical composition will not be precise.
I’m sorry, I’m an amateur: lol I know about this, but I don’t know the specific reason. When it comes to sea shipping, it’s likely even more complicated. . .
The materials are 316 and 304. The customer has not yet started using it officially; it is located by the sea. The problem at present is that the forgings are rusting severely, while the bars are in much better condition
It’s a matter of material; for coastal environments, 316L is the best choice, as it resists salt spray corrosion and similar issues
Hello, I have learned about electrochemical corrosion. Even with 316L in this case, forgings rust more severely than bars.