EFFECT OF MICROSTRUCTURE ON FATIGUE PROPERTIES IN LOW AND ULTRA-LOW CARBON STEELS

Ultra-low carbon steel containing phosphorus and copper (P-Cu steel) has both a higher fatigue limit and better crack propagation resistance than conventional low carbon steels with the same tensile strength. In this paper, the mechanism for improving the fatigue properties of P-Cu steel is discussed on the basis of microscopic observations by electron microscope and measurements of crack closure behaviour for small and long fatigue cracks. The excellent fatigue limit and small-crack propagation resistance in P-Cu steel can be attributed to solution hardening caused by phosphorus and precipitation hardening caused by epsilon-Cu. On the other hand, the superior resistance to long-fatigue crack propagation was caused by grain coasening which occurs with reduction of carbon content, leading eventually to roughness-induced crack closure.

  • Supplemental Notes:
    • Soc Materials Sc, Japan, v 40 n 458, Nov 1991, p 1415 [7 p, 15 ref, 3 tab, 12 fig]
  • Authors:
    • Yokomaku, T
    • Kinefuchi, M
    • Minokata, Y
  • Publication Date: 1991

Language

  • Japanese

Subject/Index Terms

Filing Info

  • Accession Number: 00716242
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Feb 28 1996 12:00AM