Effect of air cooling time on temperature and microstructure uniformity of 960 MPa high strength steel by direct quenching. Issue 11 (3rd November 2022)

• Record Type: Journal Article
• Authors: Yang, X.; Yu, W.; Tang, D.; Chen, Z.; Fan, J.; Shi, J.; Wang, L.; Sun, D.
• Is Part Of: Materialwissenschaft und Werkstofftechnik. Volume 53:Issue 11(2022)
• Page Start: 1347
• Page End: 1356
• Publication Date: 2022-11-03
• Subjects: High strength steel -- online-quenching -- interval air cooling -- temperature uniformity -- hardness; Hochfester Stahl -- direktes Abschrecken -- Intervall Luftkühlung -- gleichmäßige Temperaturverteilung -- Härte; Materials -- Periodicals; Materials -- Testing -- Periodicals; 620.1
• DOI: 10.1002/mawe.202100267
• Languages: English
• ISSNs: 0933-5137

Abstract

Abstract: In order to improve the temperature and microstructure uniformity in the thickness direction of online‐quenching 960 MPa high strength steel, the finite element software ADINA and the experiments have been used to analyze the effect of internal air cooling on temperature variation in the thickness direction during the online quenching process. The results showed that the interval air cooling could effectively improve the uniformity of temperature, microstructure and hardness in the direction of thickness of steel plate during the online quenching process. When air cooled for 3.2 s, the temperature difference between the surface and the core of the steel plate could be reduced by 90.13 %, and the cooling rate in the core could be reduced by about 85.20 % compared with continuous water cooling condition. The hardness difference between the surface and the core could reduce from 23 HV 5 to 5 HV 5. The internal air cooling process had an influence on the matensite lath morphology compared with continuous water cooling process. The microstructures with the different cooling conditions were martensite and the properties could still meet the requirements of 960 MPa high strength steel. Abstract : The interval air cooling can improve the uniformity of temperature, microstructure and hardness in the direction of thickness of steel plate during the online quenching process. When air cooled for 3.2 s, the temperature difference between the surface and the core of the steel plate can be reduced by 88.94 %. The hardness difference between the surface and the core can reduce from 23 HV 5 to 5 HV 5.