For steel plates in the normalized state, after head forming, why is it required to carry out normalization followed by tempering after forming, rather than just normalization?
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For the 09MnNiDR material, the drawing specifies that the steel plate should be supplied in a normalized state. However, the technical documents require normalization followed by tempering after the head is formed. My understanding is that normalization alone is sufficient; so why is tempering necessary? Is it really required?
For what reasons? Please give some guidance
Meet customer requirements and respect design specifications!
Hehe, do we have to follow requirements even if they are unreasonable? If the raw material is in the normalized + tempered state, there is no issue with making this requirement after pressing; however, it is not very reasonable to make such a requirement for a normalized sheet.
This post was last edited by wanlirn on 2023-1-28 at 10:05. This design institute has considerable experience; normalizing is carried out with air cooling without any insulation. There is a huge difference in the manufacturing processes between the head fabrication plant and the steel mill, so low-temperature tempering is performed once again to further reduce the residual stresses remaining after normalizing. In fact, some head manufacturers don’t even carry out normalizing; they just control the final temperature and that’s it.
Of course, we need to consider things on their own merits; performing one additional low-temperature tempering process definitely has benefits for the shaped parts, so there’s nothing unreasonable about it