Abstract: The invention relates to a pipe for thermal cracking of hydrocarbons in the presence of steam, in which the feed mixture is guided through externally heated pipes, wherein the pipe extends along a longitudinal axis and has a number NT of grooves that have been introduced into the inner surface of the pipe and extend in a helix around the longitudinal axis along the inner surface, the inner surface into which the grooves have been introduced, in a cross section at right angles to the longitudinal axis, has a diameter Di and a radius r1=Di/2, the grooves in the cross section at right angles to the longitudinal axis, in their groove base, each have the form of a circular arc and the circular arc has a radius r2, and the grooves each have a groove depth TT which, in the cross section at right angles to the longitudinal axis, corresponds in each case to the smallest distance between the circle having the diameter Di on which the inner surface lies and the center of which lies on the longitudinal axis, and the

Abstract: A nickel-chromium casting alloy comprising, in weight percent, up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130° C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

Abstract: The invention relates to a pipe for thermal cracking of hydrocarbons in the presence of steam, in which the feed mixture is guided through externally heated pipes, wherein the pipe extends along a longitudinal axis and has a number NT of grooves that have been introduced into the inner surface of the pipe and extend in a helix around the longitudinal axis along the inner surface, the inner surface into which the grooves have been introduced, in a cross section at right angles to the longitudinal axis, has a diameter Di and a radius r1=Di/2, the grooves in the cross section at right angles to the longitudinal axis, in their groove base, each have the form of a circular arc and the circular arc has a radius r2, and the grooves each have a groove depth TT which, in the cross section at right angles to the longitudinal axis, corresponds in each case to the smallest distance between the circle having the diameter Di on which the inner surface lies and the center of which lies on the longitudinal axis, and the

Abstract: A nickel-chromium casting alloy comprising, in weight percent, up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130° C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

Abstract: A nickel chromium alloy comprising 0.4 to 0.6% carbon, 28 to 33% chromium, 15 to 25% iron, 2 to 6% aluminum, up to 2% silicon, up to 2% manganese, up to 1.5% niobium, up to 1.5% tantalum, up to 1.0% tungsten, up to 1.0% titanium, up to 1.0% zirconium, up to 0.5% yttrium, up to 0.1% nitrogen, and nickel, has a high oxidation and carburization stability, long-term rupture strength and creep resistance. This alloy is particularly suited as a material for components of petrochemical plants and for parts, for example tube coils of cracker and reformer furnaces, pre-heaters, and reformer tubes, as well as for use for parts of iron ore direct reduction plants.

Abstract: A nickel-chromium casting alloy comprising, in weight percent, up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130° C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

Abstract: A nickel chromium alloy comprising 0.4 to 0.6% carbon, 28 to 33% chromium, 15 to 25% iron, 2 to 6% aluminum, up to 2% silicon, up to 2% manganese, up to 1.5% niobium, up to 1.5% tantalum, up to 1.0% tungsten, up to 1.0% titanium, up to 1.0% zirconium, up to 0.5% yttrium, up to 0.1% nitrogen, and nickel, has a high oxidation and carburization stability, long-term rupture strength and creep resistance. This alloy is particularly suited as a material for components of petrochemical plants and for parts, for example tube coils of cracker and reformer furnaces, pre-heaters, and reformer tubes, as well as for use for parts of iron ore direct reduction plants.

Abstract: A nickel chromium alloy with 0.4 to 0.6% carbon, 28 to 33% chromium, 15 to 25% iron, 2 to 6% aluminum, up to 2% silicon, up to 2% manganese, up to 1.5% niobium, up to 1.5% tantalum, up to 1.0% tungsten, up to 1.0% titanium, up to 1.0% zirconium, up to 0.5% yttrium, up to 0.1% nitrogen, remainder nickel, has a high oxidation and carburization stability, long-term rupture strength and creep resistance. This alloy is particularly suited as a material for components of petrochemical plants and for parts, for example tube coils of cracker and reformer furnaces, pre-heaters, and reformer tubes, as well as for use for parts of iron ore direct reduction plants.

Abstract: A nickel chromium alloy with 0.4 to 0.6% carbon, 28 to 33% chromium, 15 to 25% iron, 2 to 6% aluminum, up to 2% silicon, up to 2% manganese, up to 1.5% niobium, up to 1.5% tantalum, up to 1.0% tungsten, up to 1.0% titanium, up to 1.0% zirconium, up to 0.5% yttrium, up to 1.0% cerium, up to 0.5% molybdenum, up to 0.1% nitrogen, remainder nickel, has a high oxidation and carburization stability, long-term rupture strength and creep resistance. This alloy is particularly suited as a material for components of petrochemical plants and for parts, for example tube coils of cracker and reformer furnaces, pre-heaters, and reformer tubes, as well as for use for parts of iron ore direct reduction plants.

Abstract: A finned tube for the thermal cracking of hydrocarbons in the presence of steam is defined by a tube axis and includes a plurality of inner fins. The fins are inclined at an angle of 20° to 40° in relation to the tube axis and have a flank angle of 16° to 25°.

Abstract: A nickel-chromium casting alloy comprising, in weight percent, up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130° C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

Abstract: A finned tube for the thermal cracking of hydrocarbons in the presence of steam is defined by a tube axis and includes a plurality of inner fins. The fins are inclined at an angle of 20° to 40° in relation to the tube axis and have a flank angle of 16° to 25°.

Abstract: To provide a tube which is particularly well matched to the specific demands imposed in special application areas, such as for example hydropyrolysis, the invention proposes a composite tube having a first part-tube and a second part-tube, in which—one part-tube is arranged in the other part-tube,—the first part-tube is a centrifugally cast tube, and—the second part-tube has been produced by pressure treatment from a powder.

Abstract: Metallic pipe section (10) for a pipe coil, made from one piece of pipe, comprising at least two pipe elbows (11, 12).

Abstract: A nickel-chromium casting alloy comprising up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130° C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

Abstract: In a process for the thermal cracking of hydrocarbons in the presence of steam, the charge mixture is passed through externally heated tubes with helical inner fins, and to make the temperature in the tube wall and over the tube cross section more uniform, as well as to reduce the deposition of pyrolysis coke on the tube inner wall, a swirling flow is generated in the gas mixture and is gradually merged into a core zone with a predominantly axial flow at increasing radial distance from the fins.