A Study on the Influence of aging of the Butt-welded PE100 SDR11 on Shore A Hardness and Tensile Strength

Abstract

This paper presents the results of an experimental study on the influence of aging on the shore A hardness and tensile strength of butt-welded PE100 SDR11 pipeline joints with a nominal diameter of 125 mm and wall thickness of 11.40 mm used in natural gas distribution transportation. For the experimental determination, 12 samples were taken from the body of the pipe, 9 of which were taken from the area of the butt-welded joint. The test tubes were divided into 3 groups of 4 pieces each (1 unwelded test tube and 3 welded test tubes). Using the Arrhenius method, the test tubes in 2 groups were given artificial aging treatments of 10 and 20 years. Subsequently, all 12 test tubes were tested for shore A hardness and tensile strength. For the welded samples, an increase in tensile strength was observed with increasing aging time by 6.5% for the 10-year aged samples and by 6.16% for the 20-year aged samples. For the unwelded samples, the tensile strength decreased by 3.57% for 10-year aging and increased by 5.84% for 20-year aging. Artificial aging of 10 and 20 years of natural gas transmission and distribution pipelines did not considerably influence the Shore A hardness values, as they were in the medium/soft hardness range.