Paper Title
Effect Of Pre-Strain On The Tensional Function Of X65 Pipe Line Steel

Abstract
In many cases, pipelines are subjected to tensile pre-strain during its installation or service. In response to such pre-strained history, this presentstudy focus on the plastic flow stressbetween the yield andthe ultimate strength limit. Small scale tensile test experiment of API-5L-X65 pipeline steel was conducted. In general permanent set aspect due to pre-strain, it is shown that the plastic strain have linear function to its total pre-strain, and the remaining strain capacity and strain hardening capacity decrease with increasing of pre-strain. Meanwhile, in specific plasticity aspect due to pre-strain, it is shown that the plastic flow stress under pre-strain effect can be simplified bylinear equation. Keywords- Pre-Strain, True Stress–True Strain,X65 Pipeline Steel, Flow Stress.