Installation techniques of pile foundation on some low bearing capacity soils in Nigeria

Abstract

The purpose of this research is to investigate the effects of sodium chloride concentration on the tensile behaviour of AISI 301 stainless steel. Tensile test specimens of the test steel were immersed in six different molar concentrations of NaCl: 0.1, 0.2, 0.3, 0.5, 0.7 and 1.0 M. The tensile properties of the immersed samples were taken at intervals of 10 days for a period of 50 days. Microscopic examination was equally carried out on each sample. The results obtained revealed that the tensile properties of the steel decreased with increasing concentrations and time. The most affected property (strength) is the fracture strength, having lost 19 N/mm² (2.13%) in 1.0 M NaCl solution after 50 days compared to ultimate tensile strength and yield strength with losses in strength of 10 N/mm² (1.02%) and 5 N/mm² (0.64%) respectively, in the same concentration and time. The microscopic examination revealed that the decrease in tensile properties was as a result of pit nucleation and growth. It was discovered that inclusions are point of stress raisers for pit nucleation. This paper provides information about tensile behaviour of AISI 301 stainless steel in the investigated chloride enviroments and contributes to research on tensile behaviour of AISI 301 stainless steel in chloride enviroments.

Keywords: Sodium chloride, tensile strength, pit nucleation, stainless steel, concentration.