Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (3): 121-124.DOI: 10.13251/j.issn.0254-6051.2021.03.025

• MATERIALS RESEARCH • Previous Articles     Next Articles

Continuous cooling transformation of undercooled austenite of steel for H-grade high-strength anti-corrosive sucker rod

Sun Xiaoran1,2, Zheng Wenyue1, Sun Yan2, Bai Lijuan2, Ding Hui3   

  1. 1. National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, China;
    2. HBIS Group Technology Research Institute, Shijiazhuang Hebei 050000, China;
    3. HBIS Group Shi Steel Company, Shijiazhuang Hebei 050000, China
  • Received:2020-09-04 Online:2021-03-25 Published:2021-05-08

Abstract: Effect of cooling rate on microstructure and hardness of steel for H-grade high-strength anti-corrosiue sucker rod during undercooled austenite continuous cooling transformation was studied by means of a DIL805L quenching dilatometer. The results show that the CCT curves show an obvious overall rightward shift and with very little pearlite transformation, and the ferrite-pearlite transformation zone is completely separated from the bainite-martensite transformation zone during the continuous cooling process of the tested steel. The hardness change with the cooling rate is divided into two stages, including rapid increasing at low cooling rate and tending to be stable at high cooling rate, which is related to the changing trend of microstructure. Bainite starts to form when the cooling rate is less than 1.5 ℃/s. In order to obtain excellent bainite structure, the selectable cooling rate range is very small. The experimental research can provide effective technical support for the microstructure control and process formulation of sucker rod steel.

Key words: H-grade high-strength anti-corrosive sucker rod, CCT curve, hardness, microstructure

CLC Number: