The Effects of Sulfide Inclusions on Mechanical Properties and Failures of Steel Components

Abstract

A literature review was performed to assess the effects of inclusions in carbon and alloy steels on their mechanical properties. Inclusions, including brittle oxides and more ductile manganese sulfides (MnS), affect fatigue endurance limit, fatigue crack propagation rate, fracture toughness, notch toughness, transverse tensile properties, and anisotropy of these properties with respect to the rolling direction. Significant property anisotropy has been documented, which needs to be taken into account in the design phases. Typical fracture morphologies and metallographic appearances of MnS-containing materials that the failure analyst will encounter are illustrated.

Effect of Zr, Al Addition on Characteristics of MnS and Formation of Intragranular Ferrite in Non-Quenched and Tempered Steel

“…Generally, the elongated MnS inclusions are detrimental to transverse mechanical properties, and the detriment would be more serious with the increase of the size. 24) According to the theory of heterogeneous nucleation, the higher heterogeneous nucleation ratio, the lower degree of supersaturation needed when MnS inclusions begin to precipitate, which means the growth rate of MnS inclusions could be lower. As seen in Fig.…”

“…MnS inclusions are easy to be lengthened during the forging process, leading to anisotropy in steels. 24) So MnS inclusions with low aspect ratio are always preferred. Baker et al 25) found that under the same deformation conditions, small MnS inclusions are more resistant to deformation than larger ones owing to their high surface/volume ratio.…”

Effects of Different Parameters on Initiation and Propagation of Stress Corrosion Cracks in Pipeline Steels: A Review

“…Such steels show better mechanical properties and a higher corrosion resistance compared with normal carbon steels. However, these steels still suffer from two important failure modes including hydrogen induced cracking (HIC) and stress corrosion cracking (SCC) [4][5][6]. There are numerous studies in the literature focused on these failure modes.…”

The Evolution and Thermodynamic Analysis of Inclusions in Gear Steel after Magnesium Treatment

“…Sulphides also have a significant effect on the mechanical properties of steel. However, MnS will be tensile deformation along the rolling direction in the rolling process, which is harmful to the steel's lateral performance, resulting in anisotropy [1]. In order to eliminate or reduce the adverse effects of manganese sulfide on the mechanical properties of steel and ensure the cutting performance of steel, it is necessary to modify the manganese sulfide inclusions in steel.…”