4 results about "Cooling rate" patented technology

The invention relates to the field of casting processes of martensitic casts, in particular to a high-temperature shakeout process for a large-size martensitic stainless steel cast. The high-temperature shakeout process particularly comprises the following steps of: (1) selecting an area with highest cooling speed in the cast, wherein the time of temperature reduced to be higher than a start point of the martensitic phase transformation of a material by 50-100 DEG C is a reasonable shakeout time point; and (2) after the cast is shaken out, controlling the cooling speed of all parts of the cast to be basically equivalent to the cooling speed of the parts of the cast in a sand box by adopting a method for charging a furnace and cooling with the furnace or covering a heat-preserving materialand the like. According to the high-temperature shakeout process disclosed by the invention, the sand box occupying time of the cast is shortened by reasonably selecting a shakeout temperature control point and optimally controlling the cooling conditions of the cast after the cast is shaken out, and therefore, production efficiency is enhanced and the internal stress of the cast is ensured to becontrolled at a reasonable level without generating the phenomena of overstress, cracking, and the like. The invention can solve the problems of production efficiency reduction, production capacity limiting, and the like of an integral casting factory, which are caused by keeping the temperature of the cast in the sand box for a long time, in the prior art.

The invention relates to a heat processing technology method of an austenitic ductile iron wear-resistant casting. The austenitic ductile iron wear-resistant casting is subjected to quenching processing, and the quenching processing comprises the following steps: the casting which is subjected to machining is heated to 850 DEG C-920 DEG C inside a bogie-hearth resistance furnace; thermal insulation is carried out for 1-1.5 hours; the casting is rapidly quenched into a water-soluble quenching liquid of which the temperature is 40-60 DEG C for 2-3 minutes; after quenching, the surface temperature of the austenitic ductile iron wear-resistant casting is controlled between 200 DEG C and 260 DEG C; the casting is taken out and is immediately sent into a tempering furnace for isothermal tempering processing to obtain the austenitic ductile iron wear-resistant casting, wherein the isothermal tempering temperature is controlled between 240 DEG C and 300 DEG C, and the isothermal tempering time is 2-3 hours. According to the heat processing technology method of the austenitic ductile iron wear-resistant casting, the cooling speed is high at a high-temperature phase over 400 DEG C; the cooling speed is low at a low-temperature phase below 400 DEG C; the performance of the wear-resistant casting is improved; the production cost is reduced; and the pollution to an atmospheric environment is avoided.

The invention discloses an attal brickkiln surplus heat using system, which comprises a fume heat interchanger. The smoke inlet nozzle of the fume heat interchanger is communicated with the cooling sect of the attal brickkiln through a pipeline, and a smoke vent is communicated with a discharge flue of the attal brickkiln through a pipeline. A water circulation pipeline of the fume heat interchanger is divided into two shunt-wound spur tracks, with one spur track being a heating spur track and combing back to a fume radiator from the outlet flowing though a heating radiator, and the other spur track being a bath spur track and combing back to the fume radiator from the outlet flowing though a second-class interchanger. One end of the second-class interchanger is communicated with a water source, and the other end is communicated with a bathroom. The invention fully make full use of the fume heat of the cooling sect to heat up warming water and bath water, thus saving the former big sum of money and devotion to building up a boiler, reducing the exhaust emission, increasing the cooling speed of the cooling sect of the attal brickkiln, and greatly improving the producing efficiency.