zkratka označení: NR* technický list výrobku vytvořeno :58 1/10 bezešvá trubka EN tol. dle EN/ISO 1127 NR ,0 0,075 4,0

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1 technický list výrobku zkratka označení: NR* bezešvá trubka EN tol. dle EN/ISO 1127 Art.-Nr. kg s D NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR ,588 2, ,402 1,140 2,147 1,899 1,582 1,420 2,512 1,152 1,002 1,217 0,967 1,277 0,901 0,695 1,526 0,858 0,696 0,701 0,545 0,651 0,509 0,601 0,710 0,645 0,661 0,501 0,394 0,333 0,470 0,225 0,224 0,175 0,125 0,075 3,0 1,6 3,5 3,2 2,6 2,3 2,6 3,0 1,5 4,5 2,3 1,8 1,6 1,5 2,6 2,3 2,9 1,5 2,5 1,0 1,5 1,0 1,0 1,0 33,7 30,0 30,0 30,0 30,0 28,0 26,9 26,9 26, ,3 21,3 20,0 20,0 20,0 18,0 17,2 17,2 16,0 16, ,5 13, ,2 10,0 10,0 8,0 8,0 6,0 1/10

2 D s kg Art.-Nr. 33,7 33,7 33,7 3 38,0 38,0 42,4 42,4 48,3 48,3 48,3 48,3 50,0 60,3 60,3 60,3 60,3 60,3 76,1 76,1 76,1 88,9 88,9 108,0 108,0 114,3 133,0 139,7 139,7 159,0 159,0 159,0 168,3 168,3 219,1 219,1 3,2 3,6 2,6 3,2 2,6 3,2 2,9 3,6 8,0 2,9 3,6 4,1 8,0 3,6 4,5 8,0 7,1 6,3 10,0 1,588 2,444 2,713 3,756 2,320 4,132 3,140 5,165 2,975 3,614 4,440 5,421 5,634 4,168 5,111 5,640 6,920 10,470 5,315 6,535 8,889 8,504 16,250 10,417 12,896 9,979 12,921 13,592 16,864 15,570 17,400 30,260 20,445 28,710 33,677 52,390 NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR dostupné jakosti: Montážní materiál trubky kulaté bezešvé speciální materiály žáruvzdorné 2/10

3 Pipes made of austenitic, heat-resistant steels Heat-resistant steels were specially developed for use at high temperatures. In the form of pipes, they are used in the construction of heat exchangers, for example. Characteristics of heat-resistant steels Heat-resistant steels are steels possessing good mechanical properties for short and long-term loading due to their higher alloy content of chromium, nickel, silicon, and aluminum and with special resistance to the effects of hot gases and combustion products as well as molten salt and metal at temperatures above approximately 550 C. The level of their resistance depends enormously on the reaction conditions and cannot be determined using any test method. Scaling Resistance in the Air Table 1 Type of Steel X12 CrNiTi18 9 X15 CrNiSi X 12 CrNi X 15 CrNiSi X 10 NiCrAlTi Temperature* 850 C 1000 C 1050 C 1150 C 1100 C Chemical Composition Table 2 C % Si % Mn max P max S max Al % Cr % Ni % /10

4 The scaling resistance the high-alloyed chromium-nickel steels is achieved using a protective top layer consisting primarily of chromium oxide. Additional additives, especially of aluminum and silicon, provide additional protection.. Oxidation, sulfurization, carburization, nitrogenization, and reactions with ashes and other solid or molten deposits are particularly important for the scaling resistance from a technical standpoint. The reactions can occur individually or simultaneously depending on the prevailing conditions and may have correspondingly different reaction rates... The scaling limit temperatures specified in Table 1 apply to air and are an approximation for sulfur-free combustion gases. For high water vapor contents, the actual scaling limit may be lower. For completely combusted, sulfur-free gases, a reduction of the scaling resistance by 100 to 200 C must be taken into account depending on the composition of the gas.... In combustion gases containing sulfur, there is no significant impact on the scaling resistance when a surplus of air is available. In complete combusted, sulfurous gases, though, the scaling limit is significantly reduced due to the formation of sulfide. Alloys with high nickel contents can exhibit strong scaling above the nickel-nickel sulfide eutectic point, which is approx. 640 C.... When exposed to incompletely combusted gases, carburization of the heat-resistant steels can occur. In this case, bonding with chromium can result in the depletion of this element as a mixed crystal, which is indicated by a reduced scaling resistance. The austenitic chromium-nickel steels, especially those with a high nickel content, are less sensitive than the corresponding ferritic chromium steels.... For reductive combustion gases containing nitrogen, the behavior of the steel is similar to that during carburization. 4/10

5 For deposits from the combustion gases, low-melting eutectics can form on the steel due to reaction with the scale layer, which quickly leads to the destruction of the material. The permissible temperature limits depend greatly in this case on the composition of the deposits and are generally very low, for example like when alkaline sulfates, phosphates, metals and/or heavy metal oxides are present. Sulfidation is increased the most by hydrogen sulfide. Aluminum and silicon improve resistance against sulfidation. Nickel and silicon Improve the carburization resistance.. When starting up and shutting down systems and during downtimes, combustion products may condense. If this condensate contains sulfurous acid or sulfuric acid, then you must expect a stronger reaction... Heat-resistant steels are generally used at temperatures at which the material creeps when stressed. When calculating for systems, you must use the creep strength and elongation time values provided in Table 4. Comparison of Standards Table 3 AISI S AFNOR Z 6 CNT Z15 CNS Z12 CN Z 12 CNS Z 8 NC UNI X 6 CrNiTi X 22 CrNi X 16 CrNiSi GOST 12 Ch 48 N 10 T 20 Ch 20 N 14 S - 20 Ch 25 N 20 S ChN 32 T SBB* A700 H550 H522 H525 H500 (*)=Manufacturer's Code Schöller-Bleckmann Böhler 5/10

6 When using heat-resistant steels, you must expect changes in the material in certain temperature ranges that, after cooling down to room temperature, can lead to a reduction of the ductility. The behavior of the material at the operating temperature is generally not affected by this. Mechanical Properties Table 4 Type of Steel () Hardness (HB) Elastic Limit* (N/mm²) min. 210 min. 230 min. 210 min. 230 min. 210 Tensile Strength (N/mm²) Fracture Elongation (L0=5Da longitudinal min. 40% min. 30% min. 35% min. 30% min. 30% The values apply to cold formed pipes with wall thicknesses of 0.5 to 5 mm (*)=0.2% elastic limit (**)=The values apply to sample thicknesses 3 mm. In austenitic steels with higher Cr content, the Ω phase can form the temperature range from 550 to 900 C. The Ω phase is a brittle, intermetallic compound between iron and chromium and other transition metals that do not exhibit any non-permissible changes to the ductility at operating temperatures, but that can cause the material to become brittle after cooling down to room temperature. Si and Cr promote these precipitation processes, while Ni and Al hinder them. The Ω phase is only relevant in actual practice for and. The Ω phase can be dissolved again by annealing at temperatures > 900 C. 6/10

7 Characteristic values of the long-term behavior at high temperatures 1% Elastic Limit* Table 5 Temperature for 1,000h 110 N/mm² for 10,000h 85 N/mm² N/mm² N/mm² (*)=The stress, based on the initial diameter, that leads to a permanent elongation of 1% after 1,000 or 10,000 h Creep Strength* Table 6 Temperature for 1,000h 185 N/mm² for 10,000h 115 N/mm² for 100,000h 65 N/mm² N/mm² N/mm² N/mm² (*)=The stress, based on the initial diameter, that leads to breakage after 1,000, 10,000 or 100,000 h. 7/10

8 Physical Properties Average linear coefficient of expansion between 20 C and... Table C C C (10 mm) : (m x C) Thermal Conductivity Table 8 (W) : (cm x C) 20 C C Other Characteristic Values Table 9 Density* Specific Heat** p*** (*)=g/cm³ (**)=J : (g x C) (***)=Specific electrical resistance for (O x mm²) : m 8/10

9 Processing Heat-resistant austenitic CrNi steels are characterized by a high temperature strength in addition to their good scaling resistance. For this reason, they can generally be used for purposes in which a high mechanical strength is required in addition to scaling resistance. The high temperature strength of the material is improved through the addition of titanium and aluminum so that the long-term values for this material at temperatures over 600 C are comparatively high.. Due to the NI content, these steels are more sensitive to sulfurous gases, especially in non-oxidizing atmospheres. On the other hand, they have better resistance to carburization and nitrogenization in comparison to ferritic steels. The material should not be used in continuous operation at temperatures below 900 C due to its tendency to become brittle in the Ω phase... It should only be necessary in a few cases for the user to hot-form the heat-resistant austenitic steels. The hot forming temperature is C... Due to their low yield strength and high elasticity, austenitic steels have good cold forming properties. After very strong deformation, the resulting cold hardening effects can be undone through subsequent heat treatment with fast quenching.... Annealing the austenitic steels at 900 C air temperature offers advantages In terms of cutting operations over the quenched state. In solution annealing, the steel is cooled in water or air, and for thinner walls, in air or inert gas.... When machining austenitic steels, adequate cooling must be ensured due to their low thermal conductivity. Its strong cold hardening behavior, which can make the use of dull tools or machining at the cutting depth more difficult, requires the use of sharper tools and the correct specification of the cutting depth and cutting speed. 9/10

10 Welding The heat-resistant austenitic steels are, assuming the corresponding qualifications are available, suitable for welding using all of the known methods. However, arc welding should be preferred over gas fusion welding. Welding slag must be removed. Its presence will lead to high removal rates, especially for Sulfurous oven gases, due to the formation of low-melting corrosion products. Preheating and heat treatment after welding is generally unnecessary. Filler Metals Table 10 Base Metal Electrode or Welding Rod / / Product Range We supply seamless hot-rolled and cold-processed pipes made of heat-resistant steels as well as welded pipes with dimensions and tolerances based on DIN 2462 and DIN Acceptance An acceptance test certificate according to DIN 50049/3.1 can be made available for the heat-resistant pipes. Acceptance is performed according to Steel-Iron Data Sheet /10