39results about How to "Slow corrosion" patented technology

The invention provides a lithium sulfur battery taking a transition metal material as a current collector, which comprises a positive electrode, a negative electrode, an electrolyte, a diaphragm and a battery case, wherein the positive electrode is composed of the transition metal material current collector, a sulfur-based composite applied onto the current collector, a conductive agent and a bonding agent. The transition metal current collector adopted in the battery can be corroded by the electrolyte or oxidized during the charging / discharging process, so as to release transition metal ions, which can rapidly react with an intermediate product Sn2- of the lithium sulfur battery to generate a transition metal sulfide precipitate and further prevent the Sn2- from escaping. Meanwhile, the transition metal sulfide has outstanding electrochemical activity, can improve utilization rate of active sulfur, and further improves reversible capacity. Therefore, due to use of the transition metal current collector, the performance of the lithium sulfur battery is significantly improved.

The invention discloses a method for observing the metallographic microstructure of tungsten material products, which relates to a metallographic method adopting a chemical etching method for etching and observing the metallographic microstructure of tungsten products. The method of the invention comprises the following steps: surface grinding, lapping and polishing of tungsten material products and is characterized in that: after being treated by surface grinding, lapping and polishing, a mixed solution of HNO3 and HF is utilized to etch the surface of the tungsten material product, and then an aqueous solution of K3Fe(CN)6 and NaOH is adopted to scrub the etched surface of the tungsten material product so that the metallographic microstructure of the tungsten material product can be observed. The method of the invention has low etching speed, is easy to control and eliminates an oxide film generated after tungsten is etched. In addition, the fine metallographic sample of tungsten is produced and the organization form of tungsten is represented precisely.

Provided is an aluminum alloy heat exchanger for exhaust gas recirculation system obtained by brazing a fin material to a tube material. The fin material comprises: a core material containing 0.05-1.50% by mass Si, and 0.40-2.00% by mass Mn; and a brazing material containing 3.00-13.00% by mass Si and clad on both sides of the core material. The tube material comprises: a core material containing0.05-1.50% by mass Si, 0.05-3.00% by mass Cu, and 0.40-2.00% by mass Mn; and a sacrificial anti-corrosion material containing 2.00-6.00% by mass Zn and clad on the inner surface of the core material.The ratio of the surface area Sb (mm<2>) of the fin material to the surface area Sa (mm<2>) of the sacrificial anti-corrosion material is less than 200%. According to this invention it is possible toprovide an aluminum alloy heat exchanger for exhaust gas recirculation system which has a slow corrosion rate and long service life in ammonium environments in which ammonium is contained in the condensate water of exhaust gas.

The invention discloses a formula of a special stainless steel for a crane cable coaster and a preparation method thereof. The formula of a special stainless steel for a crane cable coaster is composed of the following components in percentage by weight: less than or equal to 0.02% of C, less than or equal to 0.75% of Si, less than or equal to 0.05% of Mn, less than or equal to 0.01% of S, less than or equal to 0.02% of P, 21.00-23.00% of Cr, 8.00-9. 50% of Ni, 0.30-0.45% of Cu, less than or equal to 0.03% of N, less than or equal to 0.04% of Ti, and the balance of Fe and unavoidable impurities, with 2C being less than or equal to Ti. The formula of a special stainless steel for a crane cable coaster has the effect of reducing the rusting probability of the crane cable coaster.

The invention discloses a method for observing the metallographic microstructure of tungsten material products, which relates to a metallographic method adopting a chemical etching method for etching and observing the metallographic microstructure of tungsten products. The method of the invention comprises the following steps: surface grinding, lapping and polishing of tungsten material products and is characterized in that: after being treated by surface grinding, lapping and polishing, a mixed solution of HNO3 and HF is utilized to etch the surface of the tungsten material product, and then an aqueous solution of K3Fe(CN)6 and NaOH is adopted to scrub the etched surface of the tungsten material product so that the metallographic microstructure of the tungsten material product can be observed. The method of the invention has low etching speed, is easy to control and eliminates an oxide film generated after tungsten is etched. In addition, the fine metallographic sample of tungsten is produced and the organization form of tungsten is represented precisely.

The invention discloses a pure magnesium metallographic tissue observation method, which comprises the following steps of 1, sequentially using 600#, 1000#, 2000# and 5000# silicon carbide abrasive paper for performing grade-to-grade grinding on the surface of the pure magnesium to obtain a flat pure magnesium observation surface with the fine and dense scratching marks; 2, using a first corrosionagent for performing primary wiping corrosion on the pure magnesium observation surface; then, performing flushing by ethanol; next, performing dry blowing by an air blower; 3, using a second corrosion agent for performing secondary wiping corrosion on the pure magnesium observation surface subjected to the primary wiping corrosion treatment; then, performing flushing by ethanol; next, performingdry blowing by an air blower; 4, observing the blown and dried pure magnesium observation surface by a metaloscope. The abrasive paper scratch mark and dirty materials are removed through two-step wiping corrosion treatment, so that the pure magnesium metallographic tissue is clearly shown; the tissue form of the pure magnesium is accurately reflected; the process is simple; the control is easy;the method is suitable for being used for observing the metallographic structures of the pure magnesium in various forms such as the cast form, the cast rolling form, the hot rolling form and the heattreatment form.

The invention discloses a copper or copper alloy chemical polishing liquid which is prepared from 300-600ml / L of 92.5-98wt% concentrated sulfuric acid, 15-60ml / L of 50-70wt% nitric acid, 1-10g / L of benzotriazole methyl, 5-40g / L of lauryl sodium sulfate, 5-35ml / L of an OP emulsifier, 0.5-5g / L of sodium nitrite and the balance of water. The copper or copper alloy chemical polishing liquid disclosed by the invention is relatively simple in component, easy to operate and relatively small in atmosphere pollution. A component which is polished by using the chemical polishing liquid is uniform in surface, stable in chemical polishing quality and not easy to over-corrode, the production efficiency is greatly improved, and the production cost is lowered.

The invention relates to a heating device, in particular to a heating device for an electrochemical cleaning salt bath furnace heater in the foundry industry. The heating device comprises a shell with an open upper end and a closed lower end, and a heating core which comprises a ceramic bracket, a resistance band and two electrode connecting columns, wherein, the ceramic bracket extends into the shell and covers the opening on the upper end of the shell; the resistance band is arranged on the ceramic bracket and two upper ends of the band are bared outside the shell; and the two electrode connecting columns are respectively welded with the two upper ends of the resistance band. When in use, the heating device is directly placed in non-oxidizing molten salt in a tank body of the salt bath furnace. By utilizing the technical proposal, the resistance band of the heating core produces heat in the shell, and then the heat is diffused into the non-oxidizing molten salt outside the device through the shell so as to evenly heat the non-oxidizing molten salt. As the heating device is directly placed in the non-oxidizing molten salt in the tank body of the salt bath furnace by utilizing a built-in heating mode, the heating device has the advantages of fast heating speed and high heat efficiency so that the tank body of the salt bath furnace is evenly heated and has the characteristics of slow corrosion speed and long service life, thus finally achieving the purposes of higher cleaning efficiency and lower cleaning cost of the electrochemical cleaning salt bath furnace.

The invention relates to the technical field of electrodes, in particular to a composite lead dioxide anode and a preparation method thereof. The composite lead dioxide anode comprises a supporting material and coatings, the supporting material is foamed lead, the coatings are lead dioxide coatings, and the lead dioxide coatings are arranged on the upper surface and the lower surface of the foamedlead; the preparation method comprises the following preparation steps: collecting anode mud, cleaning the anode mud, shaping lead dioxide powder, carrying out compression molding, shaping a product,testing the service life of an anode, and performing chloride ion resistance testing. The composite lead dioxide anode is long in service life and high in stability, a compact lead dioxide layer is formed when the composite lead dioxide electrode is used due to the fact that the lead dioxide powder is inserted into the metal lead, the corrosion mechanism is dissolution, the corrosion speed is low, the service life is long, and in the high-current-density electrolysis process, the composite lead dioxide electrode can be stably used for a long period of time.

The invention discloses a method for observing the metallographic structure of pure magnesium. The method comprises: 1. Using 600 # 、1000 # , 2000 # and 5000 # Grind the surface of pure magnesium step by step with silicon carbide sandpaper to obtain a flat and finely scratched pure magnesium observation plane; 2. Use the first etchant to rub the pure magnesium observation surface once, then rinse it with alcohol, and then use a hair dryer 3. Use the second corrosive agent to perform secondary erosion on the observation surface of pure magnesium after the first abrasion treatment, then rinse with alcohol, and then dry it with a hair dryer; 4. Use a metallographic microscope to examine the dried pure magnesium Magnesium viewing surface for observation. The invention removes sandpaper scratches and dirt on the observation surface of pure magnesium through two-step abrasion treatment, and makes the metallographic structure of pure magnesium appear clearly, thereby accurately reflecting the structure of pure magnesium. The process is simple, easy to control, and is suitable for observation The metallographic structure of various forms of pure magnesium such as cast, cast-rolled, hot-rolled and heat-treated.

The invention discloses a formula of a special stainless steel for a crane cable coaster and a preparation method thereof. The formula of a special stainless steel for a crane cable coaster is composed of the following components in percentage by weight: less than or equal to 0.02% of C, less than or equal to 0.75% of Si, less than or equal to 0.05% of Mn, less than or equal to 0.01% of S, less than or equal to 0.02% of P, 21.00-23.00% of Cr, 8.00-9. 50% of Ni, 0.30-0.45% of Cu, less than or equal to 0.03% of N, less than or equal to 0.04% of Ti, and the balance of Fe and unavoidable impurities, with 2C being less than or equal to Ti. The formula of a special stainless steel for a crane cable coaster has the effect of reducing the rusting probability of the crane cable coaster.

The invention discloses a method for preparing an ultra-high-quality SOI-based bonded Ge thin film, which is to sputter a layer of a-Ge thin film on the Ge sheet and the SOI sheet after surface treatment, and then place the Ge sheet in the atmosphere. The two are bonded together, placed in an annealing furnace for low-temperature thermal annealing to achieve high-strength Ge / SOI bonding, and then chemical etching combined with chemical mechanical polishing is used to thin and polish the bonded Ge wafers to obtain ultra-high Quality SOI-based bonded Ge thin films.

The invention belongs to the field of waste battery resource recycling, and discloses a leaching system and leaching method for valuable metal in a waste lithium battery. According to the leaching method, a sulfamic acid-glucose leaching agent is pre-heated, positive electrode powder is added, and stirring and leaching in a reaction kettle are performed, Co (III) and Mn (IV) are reduced to Co (II)and Mn (II) which are dissolved in a leaching liquid with Li<+> and Ni<2+>, Li, Co, Ni and Mn leaching rate in the waste battery positive electrode powder can reach 95% or above, and recycling or reusing of Li, Co, Ni and Mn can be achieved after further processing the leaching liquid. Compared with a traditional leaching liquid, the leaching system has the advantages of greenness, environmentalfriendliness, safe and controllable leaching process and relatively good industrial application prospect.

Provided is an aluminum alloy heat exchanger for exhaust gas recirculation system, obtained by brazing a fin material onto a tube material. The fin material comprises: an aluminum alloy core materialcontaining 0.10-1.50% Si and 0.40-2.00% Mn, and having a Zn content of less than 0.05%; and a brazing material clad on both sides of the core material, and made from an aluminum alloy containing 3.00to 13.00% Si and having a Zn content of less than 0.05%. The tube material comprises at least: an aluminum alloy core material containing 0.10-1.50% Si, 0.05-3.00% Cu and 0.40-2.00% Mn; and a sacrificial anti-corrosion material clad on the inner surface of said core material and comprising an aluminum alloy which contains 2.00-6.00% Zn and which has a Si content of less than 0.10%. According to this invention it is possible to provide an aluminum alloy heat exchanger for exhaust gas recirculation system, having slow corrosion and long service life in an ammonium environment in which ammonium is contained in condensate water of exhaust gas.