Heat Treatment of Metals ›› 2024, Vol. 49 ›› Issue (7): 287-293.DOI: 10.13251/j.issn.0254-6051.2024.07.044

• PROCESS RESEARCH • Previous Articles     Next Articles

Control of grain boundary cementite of high carbon steel wire rods based on carbon segregation index

Guo Dayong1,2, Gao Hang1,2, Pan Yang1,2, Gong Wenhe3, Wang Bingxi1,2, Yang Yingqiang3   

  1. 1. State Key Laboratory of Metal Materials for Marine Equipment and Application, Anshan Liaoning 114001, China;
    2. Ansteel Iron and Steel Research Institute, Anshan Liaoning 114001, China;
    3. Wire Rod Plant of Ansteel, Anshan Liaoning 114001, China
  • Received:2023-12-15 Revised:2024-03-20 Online:2024-07-25 Published:2024-08-29

Abstract: Control technology of grain boundary cementite(GBC) precipitation based on carbon segregation index of high carbon steel wire rods was investigated. The results show that when the carbon segregation index of 0.82%C high carbon steel reach 1.23 and 1.37, cooling rate of 20 ℃/s is not fast enough to prevent GBC precipitation, and at this cooling rate, martensite, proeutectoid cementite and pearlite coexist in the microstructure of the high carbon steel at room temperature. The wire rods with this type of microstructure are not suitable for drawing. When the carbon segregation index of the high carbon steel reaches 1.17, the cooling rate of 10 ℃/s is fast enough to produce 0 level of GBC, 90% sorbite and no martensite, which is beneficial to the drawing of high carbon steel wire rods. GBC dose not appear in the 0.8%C wire rods with carbon segregation index of 1.00 under the cooling rates of 0.25-10 ℃/s. According to above results, the setup of GBC control technology based on the carbon center segregation index is necessary to meet requirement of high carbon steel wire rod drawing of customers.

Key words: high carbon steel wire rod, grain boundary cementite(GBC), carbon segregation, cooling rate

CLC Number: