Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (5): 81-86.DOI: 10.13251/j.issn.0254-6051.2021.05.013

• PROCESS RESEARCH • Previous Articles     Next Articles

Effect of tempering temperature on microstructure, strength and toughness of EH460 grade medium and heavy ship plate steel

Xiao Na1, Xu Xiaoning2, Wang Yimin2, Sun Yonghui1, Tian Yong2   

  1. 1. Analytical and Testing Center of Northeastern University, Shenyang Liaoning 110819, China;
    2. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang Liaoning 110819, China
  • Received:2020-10-23 Online:2021-05-25 Published:2021-07-21

Abstract: Effect of tempering temperature on the structure and mechanical properties of EH460 grade ship plate steel were investigated by using optical microscopy, scanning electron microscopy, electron backscattering diffraction analysis and mechanical properties testing. The results show that the tested steel tempered at 400 ℃ for 2 h has the best properties in strength and toughness, at which conditions the yield strength, tensile strength, and the impact toughness at -40 ℃ of the tested steel can reach 471 MPa, 560 MPa and 312 J, respectively. The main reasons for the improvement of low-temperature toughness of the tested steel after tempering are as follows: the decomposition of coarse M/A islands, the increase of the proportion and density of high-angle grain boundaries in the microstructure and the decrease of effective grain size.

Key words: tempering temperature, M/A island, low-temperature toughness, texture, ship plate steel

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