Whether bolts made of different materials will seize at high temperatures
Thread Content
Previously, the bolts used on the equipment were all 304 grade. Due to the high operating temperatures, many bolts became stuck and could not be removed with wrenches; ultimately, it was necessary to use a cutting machine to free them, which was quite troublesome. After researching online, I found that stainless steel has high stickiness, and this property causes it to stick together at high temperatures. After looking at the methods suggested online, I decided to use a combination of 304 and Q235B grades for the bolts and nuts. As I lack experience in this area, I would appreciate everyone’s insights
Search for this file; what’s described in it is quite clear
That’s wrong; it’s materials of the same kind that are more likely to cause choking. There are specified requirements for the material of bolts and nuts; search for them
There are specific requirements for both the procurement standards and installation process of stainless steel fasteners. The key aspect of the procurement standards is strength, while the key elements in the installation process are the appropriate lubricants and fastening methods.
It is best not to change easily the material of the fasteners used on pressure vessels and pressure pipelines, as these have been specified by the design institute. The technicians will be in trouble if something goes wrong. The issue you mentioned of stainless steel fasteners getting stuck does happen frequently. It’s not a design issue; it’s that the procurement or technical specifications and manufacturing standards weren’t properly understood. Quickly check whether there are any shortcomings in the manufacturing standards; by examining them carefully, you will find the answer.