Analysis of Suitability of Oliver Elongation Reduction Formula for X80 Linepipe-purposed Steel

Based on a comparative analysis of the result from the tensile test as for the purpose of evaluation of trial production of the Φ1 219 mm×22 mm X80 SAWL pipe，it is judged whether the Oliver elongation reduction formula as described under Standard ISO 2566-1∶1984 is suitable for the latest generation of the TMCP X80 linepipepurposed steel.The analysis reveals that when using the said formula to converse the elongation of the plate-shaped specimen of the said pipe into that of the round bar-shaped specimen，the equivalent value is bigger than the measured test value，and the absolute difference between the two values is approximately 5%，while their relative difference is about 20%，which demonstrates that the Oliver reduction formula is not suitable for the latest generation of the TMCP X80 linepipe-purposed steel.