回火处理对22MnB5热成形钢组织性能及内耗的影响

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Abstract： Hot-formed steel is widely used in the automotive industrydue to its high strength.This paper takes hotformed steel as the research object and uses metallographic microscope，scanning electron microscope，transmission electron microscope，uniaxial tensile test and internal friction meter and other testing methods to study the effect of temperingheat treatment on the microstructure，properties and internal friction of 22MnB5 hot-formed steel，and explores the variation law of microstructure，properties and internal interstitial atoms after tempering.The results show that after tempering heat treatment，the tempered martensite structure formed reduces the strength of the hotformedsteel plate，while theelongation after fracture increases.The strength-ductility productreaches the maximum at 200°C tempering. By comparing the internal friction changes of the quenched state and the 200°C tempered state， it is found that the Snoek internal friction peak and Snoek-Ké-Koster internal friction peak decrease after tempering， the internal interstitial atoms and mobile dislocation density decrease，and the decrease in solid solution Catom content and dislocation density is also the reason for the decrease in strength.

Keywords： hot-formed stel; tempering heat treatment; microstructure; mechanical properties; internal friction

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随着新能源汽车的快速发展，对汽车轻量化的要求逐步提升，同时需要保障其安全性能，因此越来越多的超高强钢在汽车上得到较多应用[1-3]。（剩余6899字）