The influence of strain rate to mechanical properties on low alloy steel ASTMA36

Abstract

Steel is a material commonly used in general application, such as bridges, buildings, automotive, ship, and in structures generally. In its application, the load will be variously accepted. Therefore, it is necessary to study the mechanical properties of the steel in a variety of loading conditions, both static and dynamic. Variations of the current strain rates quasi static tensile testing can represent the type of load to be accepted. The material used in this study is low alloy steel ASTM A36. The tensile test is conducted by the strain rates of 3 mm/min, 9 mm/min, 15 mm/min, and 20 mm/min. From the results of this study, it is concluded that the increased strain rates increase the mechanical properties of material. The highest mechanical properties at the strain rate of 20 mm/min with a yield stress value is 563.78 MPa, and the maximum tensile strength is 590.17 MPa. From the true stress investigation, the tensile stress increased with increasing strain rates. The lower mechanical properties occur at strain rate 3 mm/min and the higher at strain rate 20 mm/min. From surface hardness analysis, the harder surface is found at point 3 on the surface fracture of strain rates specimen 3 mm/min and 9 mm/min. With strain rates increased,the value of hardness surface in each specimen is decreased. Based on observations using Scanning Electron Microscope (SEM), it is seen that any increased strain rate also increases the number and size of voids.