3Elias C N, Da Costa Viana C S. Effect of ausforming on microstructure and hardness of AISI H-13 tool steel modified with niobium [J]. Materials Science and Technology, 1992,8: 785-789.
4Tsujll N, Abe G, Fukaura K, et al. High temperature low cycle fatigue behaviour of a 4.2Cr-2.5Mo- V-Nb hot work tool steel [J]. Journal of Materials Science Letters. 1996,15: 1251-1254.