44 results about "Flow-accelerated corrosion" patented technology

Belonging to the field of metal corrosion and protection, the invention relates to a periodic soaking accelerated corrosion test system for metal materials and metal protective coatings and application thereof. The system is mainly for the accelerated corrosion test of metals and metal protective coatings, significantly improves test efficiency, shortens evaluation cycle of metals and the protective coatings. The system includes a working groove and a liquid storage tank. An axial flow fan, an infrared heating lamp, an infrared heating lamp hanger, a temperature sensor I, a sample, a sample holder and a double float ball liquid level sensor are arranged in the working groove; and a temperature sensor II and a heater are arranged in the liquid storage tank. An electrical control system, a chemical pump, a liquid inlet pipeline, a leakage pipe and a ball valve are arranged outside the working groove and the liquid storage tank. The invention has the advantages of simple structure, low cost, reliable performance and long service life, and can evaluate the corrosion resistance of the metals and the protective coatings in a relatively short period of time, and significantly improve the test efficiency.

The invention relates to a Cu-contained and Cr-controlled seamless steel tube for a nuclear power station and a production method for the seamless steel tube. The seamless steel tube comprises the following chemical components in weight percentage: 0.10-0.15 percent of C, 0.90-1.20 percent of Mn, 0.20-0.45 percent of Si, not greater than 0.015 percent of P, not greater than 0.005 percent of S, 0.20-0.30 percent of Cr, 0.25-0.40 percent of Mo, 1.10-1.25 percent of Ni, 0.55-0.65 percent of Cu, 0.015-0.025 percent of Nb, not greater than 0.02 percent of Altot, not greater than 0.008 percent of N, not greater than 0.0002 percent of H, not greater than 0.003 percent of O, not greater than 0.012 percent of As and Sn, not greater than 0.020 percent of As, Sn, Pb, Sb and Bi and the balance Fe and inevitable impurities. According to the production method for the seamless steel tube, steel for a round tube blank is treated by adopting an oxygen converter through external refining and vacuum refining, and the round tube blank is produced by adopting a continuous casting method. The invention has the advantages that through adding alloying elements, such as Cu and Cr, the round tube blank with high purity, low gas content and low impurity content is obtained through strictly controlling harmful elements, and moreover, a reasonable reheating schedule, a rolling technology and a heat treating regime are formulated, so that the steel grade has much higher strength than carbon steel and is good in flow accelerated corrosion (FAC) resistance, is capable of saving wall thickness, is safe and reliable and is suitable for the demanding seamless steel tube for the nuclear power station.

The invention relates to a seamless steel tube for nuclear power and a production method thereof, belonging to the field of seamless steel tubes. The invention solves the technical problem of providing the seamless steel tube for nuclear power, and the seamless steel tube can reduce 'flow-accelerated corrosion (FAC)'. The seamless steel tube for the nuclear power comprises the following chemical compositions in percentage by weight: 0.17-0.24% of C, 0.17-0.37% of Si, 0.35-0.65% of Mn, 0.18-0.35% of Cr and the balance of Fe and unavoidable impurities. The mechanical property and impact property (20 DEG C, 0 DEG C) and high-temperature instaneous tension of the seamless steel tube for nuclear power can fully satisfy the technical requirements of the seamless steel tube for a conventional island of a nuclear power plant, and the function of 'FAC (flow-accelerated corrosion)' resistance is achieved. The invention provides a novel choice for the seamless steel tube for the conventional island of the nuclear power plant, and has wide application prospect.

The invention relates to a seamless steel tube for nuclear power and a production method thereof, belonging to the field of seamless steel tubes. The invention solves the technical problem of providing the seamless steel tube for nuclear power, and the seamless steel tube can reduce 'flow-accelerated corrosion (FAC)'. The seamless steel tube for the nuclear power comprises the following chemical compositions in percentage by weight: 0.17-0.24% of C, 0.17-0.37% of Si, 0.35-0.65% of Mn, 0.18-0.35% of Cr and the balance of Fe and unavoidable impurities. The mechanical property and impact property (20 DEG C, 0 DEG C) and high-temperature instaneous tension of the seamless steel tube for nuclear power can fully satisfy the technical requirements of the seamless steel tube for a conventional island of a nuclear power plant, and the function of 'FAC (flow-accelerated corrosion)' resistance is achieved. The invention provides a novel choice for the seamless steel tube for the conventional island of the nuclear power plant, and has wide application prospect.

The invention relates to a system and a method for sectional pH (potential of hydrogen) value adjusting of a thermal system of a thermal power plant, which are used for controlling the sectional pH value adjusting of the thermal system and enabling a water supply system and a water drain system of a low pressure heater to avoid corrosion accelerating caused by flowing. The system comprises an ammonia solution preparation system and a dosage automatic control system. The adjusting method comprises the following steps of enabling the ammonia solution preparation system to prepare a low-concentration ammonia water solution, using the low-concentration ammonia water solution as a pH value adjuster, enabling a directional dosage pipeline to adjust the pH value of the thermal system by sections, and enabling the water supply system and the water drain system of the low pressure heater to avoid corrosion accelerating caused by flowing. The system and the method have the advantages that the problem of easiness in corrosion accelerating caused by flowing in the water supply system and the water drain system of the low pressure heater in front of the furnace are solved; the content of iron in the drained water is greatly reduced, and the influence to the thermal system is avoided.

The invention relates to a vapour-liquid two-phase flow accelerated corrosion test device which is characterized by comprising a testing autoclave body, an oil bath heating jacket, an autoclave body cover, a magnetic rotating device, a high-temperature reference electrode, a graphite auxiliary electrode, a working electrode, a variable frequency motor, a potentiostat, a corrosion measurement computer, an equipment control cabinet, an inner lining, a gas-phase generator, an electric heater and a thermocouple sensor. In the invention, an electrochemical measurement method is adopted to carry out experimental study on the relevant properties of vapour-liquid two-phase flow accelerated corrosion, including the measurement of relevant coefficients of the transient corrosion property, the corrosion impedance and the corrosion reaction, the relation between mass transfer and corrosion reaction, the relation between the vapour-liquid two-phase flow pattern and the corrosion rate and production and breakage mechanism of a corrosion product membrane and the critical characteristic of the breakage. The high-speed rotation is realized and meanwhile, and the good sealing property is ensured byadopting the magnetic rotating device.

The invention relates to the field of oil and gas field corrosion research, in particular to a gas and liquid two-phase flow loop corrosion experiment device, which is applicable to coupon corrosion experiment and in-situ corrosion electrochemical test of gas and liquid two-phase flow of an oil and gas field production system on an oil pipe under the simulated working condition. An experiment testing module is arranged in a horizontal pipeline, and oil and gas field high-temperature and high-pressure fluid simulated by an experiment device is subjected to loop corrosion experiment by using an electrochemical workstation and a three-electrode electrochemical corrosion measuring device, so that flow accelerated corrosion weight loss and appearance features are obtained; an 'in-situ' electrochemical signal of a working electrode in simulated high-temperature and high-pressure fluid is monitored, so that the corrosion behavior and mechanism of the gas and liquid two-phase flow loop are mastered.

The invention relates to a method for analyzing the flow accelerated corrosion degree of a water vapor system of a supercritical unit. The method comprises the following steps: (1) making a standard color chart, and representing the colloidal iron content by taking the color of residues on each filter membrane as the color of the standard color chart; (2) directly connecting a sampling head with a water sample; (3) mounting the filter membrane, connecting the sampling head with a test point sampling pipe, filtering the water sample, enriching colloidal iron in the water sample, and drying; (4) collecting and testing the color chart of the water sample of the unit on site, emphatically the water sample with a relatively large amount of residues in the color chart, pointedly acquiring scale quantity analysis data of unit maintenance, and building a flow accelerated corrosion degree evaluation set; (5) comparing the color of the residues on the filter membrane with the color chart, quantifying the content of colloidal iron in different water samples, and quantitatively determining the flow accelerated corrosion degree according to the flow accelerated corrosion degree evaluation sample set. Compared with the prior art, the method is relatively high in accuracy, simple, feasible, low in analysis cost and relatively institutive in analysis result.

The invention relates to a common pipe ditch cast-in-place extrusion flow state concrete lining material, which is used in an extrusion flow state concrete material. strength grade of configured concrete is C30, 42.5 grades ordinary Portland cement is adopted, content of C3A is required to be less than 8%, fineness modulus of fine aggregate are 2.6-3.0, grain size scope of coarse aggregate is 5-31.5mm, sand ratio is 36-40%, coal ash occupies 20% of total weight of gelled materials, and water to binder ratio scope is controlled in a range of 0.40-0.44. Mix proportion with the unit of Kg / m3 of the concrete material is the cement of 320-355, the river sand of 630-690, the gravel of 1080-1160, the coal ash of 80-90, water of 175-185, and dosage of flow accelerated corrosion (FAC) high efficiency slushing agent is 1.5-1.8% of the weight of the gelled material. The common pipe ditch cast-in-place extrusion flow state concrete lining material conducts a 1:1 testing model test, workability index, strength index and cement dosage all meet requirements, and anti-permeability of the concrete is larger than P20. Various indexes of the concrete all meet design requirements.

The invention discloses a flow accelerated corrosion experiment test analysis method and system, and the analysis method comprises the steps: adjusting the environment condition of a test system, and enabling the test system to meet the actual operation environment condition of a thermal power generating unit; measuring the experimental system by adopting an electrochemical alternating-current impedance method to obtain electrochemical impedance spectroscopy data of the electrode system; and analyzing the acquired electrochemical impedance spectroscopy data. According to the method, the actual operation environment condition of the thermal power generating unit can be approached, in addition, the accurate FAC experiment data is greatly helpful for the mechanism analysis of the FAC, the accurate FAC experiment data can be obtained under the environment condition of an electrochemical measurement method and a control experiment system, and the FAC phenomenon in a water supply and drainage system can be eliminated.