Steel Tube Handbook - 2018

103 Technological testing (Manipulating tests) When tested in accordance with related standards the test piece shall withstand being tested without cracking. The following tests are made to prove ductility of tubular products : Bend test (Biegeversuch) – (in full size tubular sections). Test is used for pipe in sizes 2 in. or 65 mm and under. In this test a sufficient length of full size pipe is bent cold through (90°) around a cylindrical mandrel having a diameter e.g. 12 times the nominal diameter of the pipe. EN ISO 8491, ASTM A 370 (A 2,A 2.5), ČSN 420415.3 Flattening test (Ringfaltversuch) The test piece shall be flattened at room temperature between parallel flat platens until the distance between the platens H (in mm) measured under load reaches the value given by the equation in standard. Tested are tubes - D shall by 600 mm and under and with T shall by 15% of D and under. EN ISO 8492, DIN 50 136,ASTM A 370 and standards for tubes and pipes, ČSN 42 0415.4. Flaring test (Drift expanding test)/ (Aufweitversuch) The test piece shall be expanded by a tapered mandrel,having an included angle of 60° at the option of the manufacturer until the percentage increase in outside diameter shown in tables in standards is reached. D shall be 150 mm and under and T shall be max. 10 mm. EN ISO 8493, DIN 50 135, ASTM A 370, ČSN 42 0415.5. Flanging (Flange) test (Bordelversuch) The test piece shall have a flange turned over at right angles to the body of the tube to the width required by the applicable material specifications. D max 150 mm, T max. 10 mm. EN ISO 8494, DIN 50 139, ASTM A 370, ČSN 42 0415.6. Ring-expanding test (Ringaufdornversuch) The test piece shall be expanded with a conical tool until it breaks. The surface outside the fracture zone shall be free from cracks or breaks. D 18-150 mm (114,3 mm), T 2-16 mm (12,5 mm). EN ISO 8495, DIN 50 137, ČSN 42 0415.7. Ring tensile test (Ringzugversuch) The test piece shall be subjected to strain in the circumferential direction until fracture occurs. After fracture the test pieces shall not show any visible cracks without the use of magnifying aids (excluding the fracture point). D above 150 mm, d above 100 mm and T 40 mm and under. EN ISO 8496, DIN 50 138. Others additional technological tests Crush test (upsetting test) (Anstauchen test) The test piece is placed on end and crushed endwise by hammer or press to the distance prescribed by the applicable ma- terial specifications. Reverse flattening test (Reversionringfaltversuch) For testing of welds of electric welded tubing (Transverse guided) Bend test of welds (Biegeprufungen von Schweissnahten) This bend test is used to determine the ductility of fusion welds. ISO 377 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing Tube suitability for hot dip galvanization All structural steels are possible to hot dip zinc, but quality, appearance and thickness of coating influences the chemical composition of steel (the content of Si + P). For general structural steels is recommended to keep the con- tent of Si + P in range 0,13 %–0,28 %. Carbon equivalent CEV (IIW) Carbon Equivalent Value (CEV) according to the International Institute of Welding (IIW).