Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (11): 1336-1343.DOI: 10.1007/s40195-015-0331-8

• Orginal Article • Previous Articles     Next Articles

Steady-State Creep Behavior of Super304H Austenitic Steel at Elevated Temperatures

Ping Ou1,2, Long Li1, Xing-Fei Xie1, Jian Sun1()   

  1. 1 Shanghai Key Laboratory of Advanced High-Temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China
    2 School of Materials Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
  • Received:2015-07-28 Revised:2015-09-17 Online:2015-11-17 Published:2015-11-20


Creep behavior of Super304H austenitic steel has been investigated at elevated temperatures of 923-973 K and at applied stress of 190-210 MPa. The results show that the apparent stress exponent and activation energy in the creep deformation range from 16.2 to 27.4 and from 602.1 to 769.3 kJ/mol at different temperatures, respectively. These high values imply the presence of a threshold stress due to an interaction between the dislocations and Cu-rich precipitates during creep deformation. The creep mechanism is associated with the dislocation climbing governed by the matrix lattice diffusion. The origin of the threshold stress is mainly attributed to the coherency strain induced in the matrix by Cu-rich precipitates. The theoretically estimated threshold stresses from Cu-rich precipitates agree reasonably with the experimental results.

Key words: Super304H steel, Cu-rich precipitate, Creep, Threshold stress