Panzhihua, China
Panzhihua, China

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Patent
Pangang Group Co. | Date: 2016-08-09

The present invention discloses a method for preparing hypereutectoid steel rail in which the composition of the billets adopted is: C: 0.86-1.05 wt. %; Si: 0.3-1 wt. %; Mn: 0.5-1.3 wt. %; Cr: 0.15-0.35 wt. %; Cu: 0.3-0.5 wt. %; P: 0.02-0.04 wt. %; S: 0.02 wt. %; Ni: - of the content of Cu; at least one of V, Nb and Re; Fe and unavoidable impurities of the rest. The present invention further provides a hypereutectoid steel rail prepared by the foregoing method. By the hypereutectoid steel rail preparation method provided by the present invention, the high-carbon billets with a specific composition provided by the present invention can be made into hypereutectoid steel rails with good corrosion resistance and tensile properties.


The present invention relates to a high-strength, highly wear-resistant, and highly contact-fatigue-resistant steel rail and a production method thereof, and belongs to the field of black steel manufacturing technology. The present invention provides a high-strength and highly fatigue-resistant steel rail, comprising the following chemical components by weight percentage: C: 0.76%0.86%; Si: 0.6%1%; Mn: 0.7%1.5%, Cr: 0.1%0.5%, and 0.8%Mn %+Cr %1.6%; V: 0.05%0.3%, Ni: 0.1%0.35%, and 0.15%V %+Ni %0.4%; Mo: 0.03%; P: 0.02%; S: 0.015%; Fe and inevitable impurities: the remaining content, wherein, the metallurgical structure of the steel rail is fine pearlite+A, where, A is proeutectoid ferrite or proeutectoid cementite, and A2%. The tensile strength of the obtained steel rail is 1,260 MPa1,420 MPa.


Patent
Pangang Group Co. | Date: 2016-01-07

The invention relates to a high-impact-toughness steel rail and a production method thereof, and belongs to the field of steel rail material production. The present invention is to provide a high-impact-toughness steel rail. The high-impact-toughness steel rail provided in the present invention is a pearlite steel rail with 0.050.09 m of inter-lamellar spacing and 3035 J of ballistic work at normal temperature; the chemical components of the steel rail in weight percentage are: C: 0.71-0.82 wt %, Si: 0.25-0.45 wt %, Mn: 0.75-1.05 wt %, V: 0.03-0.15 wt %, P: 0.030 wt %, S: 0.035 wt %, Al: 0.020 wt %, and Fe and inevitable impurities of the remaining content. The U-type impact toughness of rail head of the steel rail manufactured with the method disclosed in the present invention can be 30 J or more, and the tensile strength is about 1,300 MPa or higher.


The present invention relates to a heat treatment method for increasing the depth of hardening layer in a steel rail, and belongs to the field of steel rail production process. The technical problem to be solved in the present invention is to provide a heat treatment method for increasing the depth of hardening layer in a steel rail and a steel rail obtained with the method. The method comprises the following steps: cooling a finished rolling steel rail by natural cooling, till the temperature at the center of rail head surface is 660730 C.; cooling the steel rail by accelerated cooling at 1.53.5 C./s cooling rate, till the temperature at the center of rail head surface is 500550 C.; increasing the cooling rate by 1.02.0 C./s and further cooling down the steel rail, till the temperature at the center of rail head surface is 450 C. or lower; then, stopping the accelerated cooling, and cooling down the steel rail by air cooling to room temperature. With the heat treatment method disclosed in the present invention, a deep-hardening layer thicker than 25 mm can be obtained in the rail head part, the portion within 25 mm depth below the surface layer of rail head has hardness equivalent to the hardness of the surface layer of rail head, and the rail head is in a pearlite structure across its cross section. Thus, the service performance of the steel rail against the wearing incurred by the contact between the train wheels and the steel rails can be improved.


The present invention discloses a bainitic steel rail containing trace amounts of carbides, wherein, the bainitic steel rail mainly consists of bainitic structures, the carbides have a length of 0.05-0.5 m, the major axis of carbides is oriented to a direction at a 50-70 included angle from the direction of the major axis of bainitic ferrite plates, and the carbides account for 1%-5% by volume. The present invention further discloses a method for producing a bainitic steel rail containing trace amounts of carbides, comprising: cooling a steel rail with residual heat after finish rolling by air cooling, till the temperature at the center of the rail head tread reaches 420-450 C.; cooling the rail head part of the steel rail by accelerated cooling at a 2.0-5.0 C./s cooling rate, till the temperature at the center of the rail head tread reaches 220-240 C.; loading the steel rail into a tempering furnace and tempering at 300-350 C. for 4-6 h; then, cooling the steel rail by air cooling to the room temperature. The steel rail provided in the present invention has outstanding wear resistance and contact fatigue resistance properties, and can meet higher requirement for the service of railroad steel rails, and the product is especially applicable to heavy-duty railroads.


Patent
Pangang Group Co. | Date: 2014-12-24

The present invention discloses a method for heat treatment of hypereutectoid steel rail, including the following steps: holding the temperature of the steel rail of which temperature is above 900 C. after finish rolling, conducting a first cooling stage for the steel rail at the first cooling speed after the temperature holding to reduce the temperature of railhead surface layer of the steel rail to 700-750 C., conducting a second cooling stage for the steel rail at the second cooling speed to reduce the temperature of railhead surface layer of the steel rail to 550 C., conducting a third cooling stage for the steel rail at the third cooling speed to reduce the temperature of railhead surface layer of the steel rail to 450 C. or less, and continuing to cool the steel rail in the air. While obtaining good tensile property, the steel rail treated by the method for heat treatment provided by the present invention can effectively reduce secondary cementite and have excellent resistance to abrasion and contact fatigue. The product is particularly suitable for heavy rails.


A method for detecting paths and amount of loss of desulfurization organic components in a flue gas desulfurization system includes preparing a to-be-measured solution and a base standard solution, and diluting the base standard solution with water to a plurality of standard solutions containing different concentrations of desulfurization organic components; adjusting the to-be-measured solution and standard solutions to have a strong acidity, respectively, such that each of desulfurization organic components in the to-be-measured solution and standard solutions exists in ion forms; heating and oscillating the to-be-measured solution and standard solutions, respectively; respectively detecting carbon elements in the standard solutions, to form a linear relationship between concentrations of the desulfurization organic components in the standard solutions and detected carbon element data; and detecting carbon elements in the to-be-measured solution, and obtaining a total concentration of the desulfurization organic components in the to-be-measured solution according to the linear relationship.


Patent
Pangang Group Co. | Date: 2013-10-24

A method of producing titanium metal with titanium-containing material which includes mixing, pressing and drying the titanium-containing material with a carbonaceous reducing agent to obtain a resultant as a first anode. Using a metal or an alloy as a first cathode, and using an alkali metal chloride molten salt and/or an alkaline earth metal chloride molten salt as a first electrolyte to constitute a first electrolysis system, to perform pre-electrolysis in an inert atmosphere to obtain a residual anode. After the residual anode is washed, molded and dried, using the residual anode as a second anode, using a metal or an alloy as a second cathode, using an alkali metal chloride molten salt and/or an alkaline earth metal chloride molten salt as a second electrolyte to constitute a second electrolysis system, to perform electrolysis in an inert atmosphere to obtain titanium metal powder.


Patent
Pangang Group Co. | Date: 2013-08-23

The present disclosure discloses a heat treatment method for a bainitic turnout rail, which includes: naturally cooling the turnout rail at a temperature in an austenite region after being finishing rolled to 450-480 C. at a tread center of a rail head of the turnout rail; accelerated cooling the naturally cooled turnout rail to 230-270 C. at the tread center of the rail head, a cooling rate at the tread center and a non-working side of the rail head being 1.5-5.0 C./s, a cooling rate at the working side of the rail head increasing by 0.1-1.0 C./s based on 1.5-5.0 C./s; continuously accelerated cooling the working side, the tread center and the non-working side of the rail head at a cooling rate of 0.05-0.25 C./s to decrease a temperature of the tread center of the rail head to 265-270 C.; and finally, naturally cooling the turnout rail to an ambient temperature.


A pearlitic steel rail with high strength and toughness and a producing method thereof. The producing method comprises: controlling the following processing conditions in a rolling procedure to produce the pearlitic steel rail with high strength and toughness: initial rolling temperature of 1,120-1,180 C., final rolling temperature of 840-880 C., rail profile reduction in last two rolling passes of 6%-12%; the steel rail is cooled to 600 C. or lower at a cooling rate 2.0 C./s after final rolling, and then air-cooled to room temperature; the chemical composition of the steel rail meets the following requirements: C: 0.75%-0.84%, Si: 0.30%-0.80%, Mn: 0.50%-1.50%, V: 0.04%-0.12%, Ti: 0.004%-0.02%, and 0.10%V+10Ti0.25%, [N]30 ppm, P0.020%, S0.008%, with the remaining content consisting of Fe and inevitable impurities.

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