Issues with impact testing of studs and nuts
Thread Content
GB150.2 7.13 specifies impact test requirements for steel bars used in low-alloy steel studs, and Table 14 further outlines such requirements for studs intended for use at low temperatures. So the question is: 1. Do low-temperature studs need to undergo two impact tests? Process the rough steel rod once, and then process the finished studs once more? 2. Is there hot forming during the processing of studs? Is the heat treatment state of the raw material changed during the processing? If nothing is changed, is it unnecessary to conduct another impact test on the finished studs? 3. The nut should not be able to undergo an impact test, right? Only one impact test is performed on the raw steel rod?
During the production of studs, various manufacturing processes such as drawing, cold heading, heat treatment, and phosphating are employed; the properties of the raw materials used for these studs have a direct impact on the results of the impact tests. Nut specimens should be made from the same batch of material as those used for the studs
In other words, is an impact test conducted once on each of the steel rod and the finished stud?
Yes, similar to the steel plates used for pressure vessels – they undergo re-inspection upon arrival at the factory, and the heat treatment is carried out using test plates from the same furnace
Who conducts the impact test on steel rod billets? Is it done by a stud processing company? Should it still be the steel rod supplier who does it and provides a report to the stud processing company?