Questions about the delivery condition of the materials?
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I would like to ask why some materials need to be supplied in the normalized and tempered condition, while others need to be supplied after annealing? What’s the difference?
This is probably not something that can be explained in just a few words – different materials, different thicknesses, different usage environments, and so on.
I know that materials such as ordinary carbon steel and low-alloy steel are usually supplied after normalizing and tempering, while nickel-based alloys like Monel are supplied after annealing. Why is that?
Plain carbon steel and low-alloy steel can be used in their hot-rolled state. Nickel-based alloys are less encountered and not well-known.
This post was last edited by fzujunru on 2018-11-19 at 22:59. The purpose of heat treatment is to alter the internal structure of steel and improve its mechanical properties. The four key factors in heat treatment are heating temperature and cooling rate. The choice of heat treatment method depends on the material and the desired outcome; the alloy phase diagram serves as an important reference. Tempering is usually carried out after quenching, but normalizing also results in thermal structures and structural stresses, which increase the brittleness of the material and can lead to hardened structures as well. Tempering can eliminate these defects. Therefore, some materials require normalizing followed by tempering; they are to be supplied in the annealed state for nickel alloys. Note 2 in Table 5-7 of JB/T4756-2006 P95 (continued) states: “Note 2: In international standards, some grades are specified as ‘annealed’; here, in accordance with domestic conventions, it is referred to as ‘solution-treated’.” So... for more, I’m not sure, haha. You can refer to classic textbooks, such as Professor Cui Zhongqi’s \"Metallogy and Heat Treatment\" from Harbin Institute of Technology
It is related to material standards, material thickness, operating conditions, etc.
In simple terms, it mainly aims to improve the intergranular structure of metals and enhance their performance. As for how the intergranular structure can be improved, which properties are enhanced, and how such improvements occur, one can refer to books on metal materials science; reference 7# is recommended. :)
Bro, the scale of this issue is big enough to warrant two papers.