S500M |
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HIGH STRENGTH FINE GRAINED STRUCTURAL STEEL
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Specification DH-E57-A |
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| S500M is a thermo-mechanically rolled, fine-grained structural steel which
has in its delivery condition a minimum yield strength of 500 MPa. Due to its chemical composition, this material has a low carbon equivalent and hence excellent weldability. It is predominantly used in steel structures with high demands on weight reduction, weldability and safety, e.g. offshore structures and platforms. Product descriptionDesignation and range of applicationS500M can be delivered in thicknesses from 16 to 75 mm (0.62 to 2.95 inches) according to the dimensional program. Other dimensions may be possible on request. S500M fulfills the requirements according to NORSOK Standard MDS - Y55, Rev. 2, which refers to the steel grade S460M3 according to prEN 10 225. The maximum plate thickness according to MDS - Y55, Rev. 2 is 40 mm, but will be extended in the revision. Chemical composition For the ladle and product analysis the following limiting values1) are applicable: |
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1) Additionally the following restrictions apply: Nb+V ≤0.09 % and Nb+V+Ti ≤0.11 %. CEV(IIW) ≤0.43 % CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 PCM(Ito) ≤0.22 % PCM = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B If the steel has to be pre-qualified according to prEN 10 225, API RP2Z or other standards, the range of the chemical composition may be restricted. |
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| Delivery condition Thermo-mechanically rolled and, if necessary, accelerated cooled (M). Mechanical and technological properties in the delivery condition Tensile test at ambient temperature – transverse test specimen -
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| ReH/Rm (Y.S./T.S) ≤0.90 1) 1) If the Yield Strength ReH is not apparent, Rp0.2 is indicated. The values in brackets are for information only. Tensile test perpendicular to the product surface at ambient temperature Option: In accordance with EN 10 164, Quality Class Z 35, the following through thickness properties on tensile test specimens perpendicular to the plate surface can be tested in the delivery condition or in the PWHT condition (according to Norsok standard MDS - Y50, Rev. 2).
Impact test on Charpy-V-test specimens – transverse specimens - 1)
The specified values are minimum values for the average of 3 tests. The lowest individual value is not to be less than 70 % of the specified minimum. For plate thickness below 12 mm the test will be carried out on Charpy-V-test specimens with reduced width. The minimum impact value will be decreased proportionally 1) Additionally, Charpy-V-notch mid-thickness tests are required for thicknesses > 40 mm. Testing Tensile and impact tests are carried out once per heat and plate thickness at one end of a rolled plate in ¼ of the plate width. The tensile test is carried out in accordance with EN 10 002-1. If required, the tensile test in through thickness direction is carried out in accordance with EN 10 164 at one end of the plate in ½ of the plate width. The impact test is carried out on Charpy-V-transverse test specimens in accordance with EN 10 045-1. The test temperature is -40 °C (-40 °F), if not otherwise specified. Options: •Yield strength range ReH from 500 to 580 MPa can be agreed. •Tensile test perpendicular to the product surface according to prEn 10 225, Option 13 (see above). •Ultrasonic testing according to EN 10 160. •Strain ageing testing according to prEN 10 225, Option 12. •Tests in PWHT condition, according to prEN 10 225, Option 10. •Pre-qualification according to prEN 10 225, API RP2Z or other standards can be agreed. Please contact DILLINGER HÜTTE GTS before placing the order. Unless otherwise agreed, the test results are documented in a certificate 3.1.B in accordance with EN 10 204. Identification of plates The marking is carried out via steel stamps with at least the following information: the manufacturer’s trademark, steel designation (S500M), heat number, rolled plate number and, if applicable, the third party inspection stamp. Fabrication properties The entire fabrication and application techniques are of fundamental importance for the reliability of products manufactured with these steels. The fabricator should ensure that his calculation, design and manufacturing methods are suitable for the intended application, are state of the art and, that they correspond with the properties of the material. The customer is responsible for the selection of the material. General recommendations concerning fabrication of fine grained structural steels are given in Stahl-Eisen-Werkstoffblatt 088, ECSC Information Circular No. 2 and prEN 1011- 2:1999. Cold forming Cold forming means forming below the maximum allowable stress relief temperature of 580 °C (1076 °F). S500M has excellent cold forming properties. With regard to the higher yield strength the steel needs 1 /3 higher bending forces compared to S355 of the same thickness. Flame cut edges have sufficient toughness to allow cold forming. Cutting defects shall be ground in the bending area before cold forming to avoid strain concentration. Cold forming is always related to a work hardening of the steel and to a decrease in toughness. For intense cold deformation the loss in toughness can be mainly recovered through a heat treatment in the temperature range 550 – 580 °C (1022 – 1076 °F). In this case we recommend you to consult us prior to ordering. If plates are cold formed during the fabrication process the material properties for the corresponding condition can be tested in strain aged condition. Hot forming Hot forming means forming at temperatures above the maximum allowable stress relief temperature of 580 °C (1076 °F). Hot forming is not allowed for thermo-mechanically rolled steel, because the particular microstructure would be altered and can not be restored by a subsequent heat treatment. Flame cutting Flame cutting can be done without preheating. The hardness at the flame cut edge is moderate thanks to the low hardenability of the steel. Welding S500M is characterized by a low carbon content and low carbon equivalents. This results in a low heat affected zone (HAZ) hardness, a low sensitivity to hydrogen induced cold cracking and in a good toughness in the heat affected zone. Experience has shown that for best properties the weld cooling time t8/5 should be between 10 and 30 seconds. The welding parameters shall be chosen accordingly. In the weldability tests heat inputs up to 4.5 kJ/mm corresponding to t8/5-times of 45 up to 50 seconds were also successfully applied. The raised yield strength of the base material must be taken into account, when the filler materials are chosen. To achieve good toughness the weld metal should not be too much alloyed with Mo and Cr. In this regard evenmatching or moderate overmatching is considered to be the best choice. Good results were obtained using a wire with 1.3 % Mn, 1.2 % Ni, 0.4 % Mo. Higher alloy contents in the weld would raise the cold cracking sensitivity of the weld metal so that higher low preheat/interpass temperature would become necessary and one could not profit from the low sensitivity of the steel. A stress relief heat treatment after welding can change the properties of the weld metal by increased temperature and annealing time. The yield and strength are generally reduced, thus, if a post-weld heat treatment is planned during or after the fabrication, this must be already considered when selecting the filler materials. Heat treatment If a heat treatment has to be carried out for reasons of stress relieving, in order to reduce work hardening, or if it is requested by the applicable standards, this treatment shall be performed at 550 - 580 °C (1022 – 1076 °F). Higher temperatures and holding times exceeding 4 hours could affect the mechanical properties of the material. General technical delivery conditions Unless otherwise agreed, the general technical delivery requirements in accordance with EN 10 021 apply. Tolerances Unless otherwise agreed, the flatness and the tolerances will be in accordance with EN 10 029, with class A for thickness tolerance. Special flatness (e.g. 5 mm/m) may be possible on request. Surface Quality Unless otherwise agreed, the specifications will be in accordance with EN 10 163, class A3. General note If special requirements, which are not covered in this material data sheet, are to be met by the steel due to its intended use or processing, these requirements are to be agreed before placing the order. |
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