›› 1993, Vol. 29 ›› Issue (4): 29-35.

• Article • Previous Articles     Next Articles

IMPROVEMENT ON RESISTANCE ULTRA-HIGH STRENGTH STEEL TO STRESS CORROSION CRACKING BY STRAIN-AGING

Gao Ming;Jing Tianfu;Zhang Jingwu;Xu Shoutian;Zhang Qi Xiong Zhifu   

  1. Yanshan University The mechanical and Electrical Engineering College of Tianjin The Third Institute of Astrogation Ministry
  • Published:1993-07-01

Abstract: The effect of strain-aging strengthening and toughening of 15CrMnMoV, a low carbon martensitic high strength steel, was compared with the effect of conventional quench-tempering strengthening and toughening of three medium carbon martensitic ultra-high strength steels 40iMnCrNiMoV(300M),45CrMnMoV(D6AC), 28Cr3SiMnCrNiMoWV(28Cr3). A high strength (δ0.2=1500~1800MPa) and a high toughness (KIC=85~110 MPa√m, KISCC=76~95MPa√m, KISCC/KIC>0.85) were achieved via strain-aging for ISCrMnMoV steel, moreover, its temper brittleness and cryogenic toughness were improved. In addition to solid-solution hardening, the analysis results of SEM. TEM and inverse pole figures indicate that numerous potential cleavage interface formed by intense texture have a remarkable effect of strengthening and toughening on strain-aged 15CrMaMoV steel. The aging following deformation has a small effect on strength, but the overaging has a remarkable effect on toughness. The combination of delaminating and overaging gives rise to a very high threshold KISCC of strain-aged 15CrMnMoV steel in 5% NaCl aqueous solution.

Key words: Strain-aging, Stress corrosion cracking, Ultra high strength steel