Effect of Hot Rolling Process Parameters on Microstructure Transformation and Microstructure of 45MnSiV Steel

Abstract

The effects of final rolling temperature, cooling rate and deformation on phase transition point, the duration of the phase transition and the pearlite laminar layer of non-quenched and tempered steel 45MnSiV were studied by simulating the process of rolling and post-rolling cooling on Gleeble-3500 thermal simulator and thermal expansion tester. The results show that: the ferrite and pearlite transformation temperature ranges from 510 °C to 700 °C, and the bainite transformation temperature ranges from 400 °C to 500 °C when the steel is continuously cooled at a final rolling temperature of 950 °C, and the martensite transforming temperature is 300 °C under high cooling rate (> 10 °C/s); The pearlite laminar spacing decreases with the decrease of final rolling temperature. It can be seen that the rolling deformation increases the temperature at which the test steel undergoes a phase change at each cooling rate by comparing the results of deformation and no-deformation test at 950 °C. The effect of time advance on the phase transition zone of ferrite and pearlite is particularly obvious, but the effect on the phase transition temperature and time of the bainite and martensite phase transition is not obvious. When the final rolling temperature remains constant, the Rockwell hardness value of the test steel gradually increases, and the pearlite layer spacing decreases with the decrease of ferrite transformation temperature gradually and the increase of the cooling rate.

Study on the relationship between process organization and properties of 45MnVS non-tempered steel

“…There is a significant effect of cooling rate on the microstructure ratio and mechanical properties of 45MnVS steel, which is because as the cooling rate increases, the greater the subcooling in the cooling process, which leads to a lower pearlite phase transformation temperature, an increase in the content of sorbite and troostite, and an increase in the strength and hardness of the experimental steel. On the other hand, with the increase of cooling rate, the pearlescent layer spacing decreases, so the plastic change of the experimental steel is small, so the tensile property of the experimental steel can be improved by increasing the cooling rate [23].…”

Pengaruh Variasi Persentase Reduksi pada Proses Pengerolan Panas terhadap Sifat Mekanik dan Struktur Mikro Baja Laterit

“…Bijih laterit dapat ditingkatkan kualitasnya dengan menurunkan kadar pengotornya dan juga dipadu ulang dengan baja murni yang mempunyai kualitas yang baik [4]. Proses pemaduan logam dapat dilakukan dengan proses pengecoran sehingga diperoleh komposisi baja laterit yang diinginkan [5].…”