STEEL TUBE AND PIPE HANDBOOK - February 2012

104 Mechanical and technological testing of tubes and pipes The tubes and pipes shall be subjected to the tests specified in individual standards of technical delivery conditions. Mechanical testing Tensile test at room temperature (Zugversuch bei Raumtemperatur) Determined values: The upper yield strength R eH or the 0,2% proof strength R p0,2 (MPa) The tensile strength R m (MPa) Elongation Amin. (%) EN ISO6892-1, DIN50 145,ČSN42 0310,ASTMA370 (ASME SA 370) Tensile test at elevated temperature (Zugversuch bei erhohter Temperatur) Determined values: The proof strength at the agreed temperature R p0,2 (MPa) EN ISO6892 - 2, DIN50 145,ČSN42 0312 Hardness test (Härteprufung) (according to agreement and possibilities) Detected values: Brinell: EN10003, EN ISO6506,DIN50 351,ČSN42 0371,ASTME 10 Rockwell: EN 10004,EN ISO 6508, DIN 50 103, ASTM E 18 Vickers: EN ISO 6507,DIN 50 133,ASTM E 92, ASTM E 384 Conversion table hardness to R m : DIN 50 150 Impact test at 20°C ( Kerbschlagbiegeversuch bei 20°C) Impact test at low temperatures (Kerb. bei niedrigen Temperaturen) The possibility of execution of examination is depended on dimensions of tubes Determined values: Minimum average absorbed energy KV (impact energy) (J) EN ISO148-1, EN10045-1, DIN50 115, ČSN42 0381, ASTMA370 (ASME SA 370) Creep testing (Langzeitwarmfestigkeit) The creep rupture properties shall not be subject to verification, the steels are tested at verification of products technology Determined values: The creep proof strength ( Zeitdehngrenze) R T (t/A/T) is the tension, which in time t at temperature T bring about A % of middle durable relative elongation of length of test specimen. E.g. A =1%, t = 10 000 hours, T = 500°C - R T 10 000/1/500 = 70MPa The creep rupture strength (Zeitstandfestigkeit) - R mT (t/T) is the tension, at which durable activity at temperature T is middle time t until fracture of specimen. E.g. tension 100 MPa results in the time t = 10 000 hours and at temperature T = 600°C the fracture of component - R mT 10 000/600 = 100 MPa Data are presented in annexes of standards and can be used for calculations. At the present time is used second value and for stability calculations is compared in under creep area with proof strength at elevated temperature. For calculations is used always lower value. EN 10291 +Bbl 1, ČSN/STN 42 0351 (42 0302), ASTME139 Fatique testing – test is not included in standards for tubes and pipes