Zhihu netizens ask: Why do some metal materials become abnormally brittle or even break at low temperatures? Previously, it was reported in the news that certain steels undergo brittle fracture in winter. What is the physical mechanism behind this? Is there any way to improve the low-temperature toughness of metal materials and ensure their reliability in extremely cold environments?
Steel has the phenomenon of cold brittleness, especially for metal materials with high phosphorus content. The phenomenon of cold brittleness is more severe, and it has indeed occurred many times in history due to major accidents caused by steel cold brittleness. For example, the sinking of the Titanic, which represents love, was ultimately discovered to be caused by the high content of harmful impurity phosphorus P in the steel used for shipbuilding.
In history, there have been incidents of truck axle breakage and the problem of power poles collapsing in extremely cold and freezing weather, both of which were caused by cold and brittle factors.
Generally, improving the smelting quality of steel, increasing purity, and reducing phosphorus content can solve the problem of cold brittleness.
Previously, we were unaware of the significant harm caused by phosphorus. Now that we know, our smelting technology can control it and prevent this phenomenon from occurring. The steel produced in China now does not need to worry about this issue at all.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.