Very high cycle fatigue properties of 2000 MPa ultrahigh-strength steels

Abstract

The microstructure, mechanical properties and very high cycle fatigue (VHCF) properties of two 2000 MPa ultrahigh-strength martensitic steels were investigated. Results show that the newly developed steel possesses lower ultimate tensile strength but higher yield strength compared with the conventional steel, as well as a higher impact toughness and fracture toughness due to its better cleanliness and tempering at a higher temperature. Both steels experienced a typical VHCF fracture process. The newly developed steel had higher fatigue strength and longer fatigue life at the same stress amplitude compared with the conventional one, which could be related to its lower crack growth rate and better toughness.

High-performance reality of 55SiCrV spring steel processed by the rapid-induction heat treatment

“…With the development of the automotive industry, the designed strength of the suspension spring steel (SSS) has increased from 800 ∼ 900 to 1200 MPa, which demands the tensile strength of the next generation SSS to exceed 2000 MPa [1,2]. The medium carbon high silicon martensitic steels, such as 54SiCr6 or 55SiCr, are commonly used for these applications.…”