7Douglas G. stalheim. Alloy designs for high strength oil and gas transmission[J]. The Minerals, Metals & Materials Society, 2006,12(1) :46-48.
8Charleux M, Poole W J, Militzerm, et al. Precipitation behavior and its effect on strengthening of an HSLA-Nb/Ti steel[J]. Metallurgical and Materials transaction,2001,32A: 1635-1647.
9Shanmugam S,Misra R D K, Hartmann J. Microstructure of high strength niobium-containing pipeline steel[J]. Materials Science&Engineering, 2006, A441 : 215-229.
