TH6036B - Processes and tools for heat treatment of carbon steel wire to obtain a detailed terlitic structure. - Google Patents

Abstract

Heat treatment on carbon steel wire which is maintained above the transition temperature Ac3 to obtain a fine perlitic structure. by passing it in a packed tube Gas without force venting and surrounded by fluid for heat transfer The exact relationship between the diameters The center of the wire, the diameter of the pipe and the conductivity The heat of the gas is enough to ensure that the wire is still cool. temperature below temperature Acl change in the pre-time of the perlytic tip and complete perlysis within Under the temperature state, almost constant

Claims (9)

1. Method of heating the carbon steel wire to obtain a fine perlite structure, which prior to this operation the wire maintains a temperature above Ac3 transformation temperature to obtain austenitic. The homogeneous method consists of steps (a) cooling the wire from high temperatures. Than Ac3 transition temperature to a less than Ac1 transition temperature and (b) perlite. The Acl transition temperature and such steps (a) and (b) are performed by passing a wire in one or more ducts, which are filled with gas without force and which is surrounded Fluid for heat exchanger So that the heat transfer takes place from the wire through the gas and through the tube to the heat exchanger and to select the pipe type. Wire and gas For that relationship The following is enough At least in the aforementioned (a) step 1.05 less R Less than 15 (1) 5 less K less than 10 (2) where R = Dti / Df K = (LogDti / Df) * Df2 / l Dti is The internal diameter of the pipe in mm, Df is the diameter of the wire in mm, Df shall not be large, resulting in 6 mm, l is the thermal conductivity of the gas at 600 ° C in watts per meter per Kelvin and log is a natural log. 2. Method according to claim 1, which later cools the wire from The temperature above the Ac3 transition temperature is set to which is lower than the Acl transition temperature and the constant temperature. Of the wire in the compartment + 10 ° C. From such temperature It is longer than the perlation time by exchange adjustment. Heat changes and subsequent relationships will follow in the area. Single or multiple areas of a single pipe or multiple pipes in which the rate Fastest perliteization 1.05 less R less than 8 (3) 3 less K less than 8 (4) 3. Method according to claim 2, which maintains the temperature of the wire in the range The temperature does not occur + 5 degrees Celsius from the specified temperature. 4. Method according to claim 2 or 3, in which the adjustment is made by conversion Change the inside diameter of one or more pipes or tubes. 5. Method according to claim 2 or 3, which is adjusted using pipes. At least two pipes In which their length is different 6. Machine for heating operation on steel wire. Carbon to obtain a detailed perlite-like structure by thermal processing maintains the temperature of the wire above the Ac3 transformation to obtain a homogeneous austenite, an apparatus consisting of (a) a machine for making the wire. Cooling from a higher temperature Ac3 transition temperature down to a lower temperature Acl transition temperature and (b) perlitization of Wire at lower temperatures Temperature change, Acl coolers and perlite Such session Including at least one pipe Move the wire through the filled gas tube. In a duct that is free from force and heat exchange fluid around the pipe in a way in which heat transfer It is formed by wire through gas and through tubing to heat transfer fluid / Choose the type of wire and gas pipe to at least the following relationships For the machine Such cooling is 1.05 less than R less than 15 (1) 5 less than K less than 10 (2) where R = Dti / Df K = (LogDti / Df) * Df2 / l Dti is the inner diameter of the pipe in m. M Df is the diameter of the wire in mm, Df must not be large, 6 mm, l is the thermal conductivity of the gas at 600 ° C in watts per meter per Kelvin and log is natural log. 7. The machine according to claim 6, which is a single pipe or multiple pipes of Perlitization is so that it can keep the wire at a temperature range of + 10 ° C from a given temperature. Provided which is lower than the Acl change temperature for a period Longer than the perlation period by adjusting the exchange The heat and the following relationships are sufficient in one region. Or multiple areas of a single pipe or multiple pipes, which the perlite rate Session fastest 1.05 less R less than 8 (3) 3 less K less than 8 (4) 8. Machine according to claim 7, which is one or more pipes of Perlitization is so that the temperature of the wire does not differ up to + 5 ° C from the given temperature. 9. The machine according to claim 7 or 8 which diameter Inside of a pipe or at least one variable pipe 1 0. The machine according to claim 7 or 8, which the Perlite Session includes at least two pipes. In which their length is different