97av.comI男女全黄一级一级高潮免费看I日女人免费视频I久久精视频I三级黄色片子I国产精品久久久久久久久久直播

Development trend and factors of anti corrosion spiral steel pipe company

There are some special corrosion forms in fresh water, such as abrasion corrosion of metal components with high speed in river water (such as turbine parts of power station and ship propeller) due to high sediment content; metal acid corrosion caused by accumulation of microorganisms in Lake and marsh water. 2) Influence of fresh water corrosion Factors such as pH value of water, concentration of dissolved oxygen, large diameter spiral steel pipe, other dissolved components and temperature, flow rate and other environmental factors have great influence on fresh water corrosion. ① For Fe, Ni, Mg, CD and other metals, the relationship between corrosion rate and pH value varies greatly in different pH range. For example, in the range of pH = 4 ~ 9, the corrosion rate of iron and steel is high The pH value of water is almost unchanged. This is because the corrosion of iron is controlled by the diffusion of oxygen. The hydroxide film formed during iron corrosion covers the surface of steel, and oxygen must pass through the membrane to produce depolarization reaction; when pH > 9, it is conducive to the formation of hydroxide film, so the corrosion rate decreases with the increase of alkalinity; when pH < 13, the membrane dissolves The corrosion rate increases with the increase of alkalinity; when pH is less than 4, the film also dissolves, and the corrosion degree increases rapidly with the increase of acidity. ② Dissolved oxygen the content of dissolved oxygen in water is an important factor affecting corrosion. The corrosion rate of metal is directly proportional to the concentration of dissolved oxygen. When the content of dissolved oxygen exceeds the fixed value, the metal changes from active state to passive state The results show that the stability of the oxide film increases and the corrosion rate decreases sharply. However, in acidic fresh water or high salinity fresh water, the increase of oxygen content can not passivate aluminum and other passive metals, and the corrosion rate will still increase. Anti corrosion spiral steel pipe company is widely used in petroleum, chemical, electric power, water conservancy, mining, steel structure and other industries, as well as natural gas, gas, steam, heating, foundation piling, building structure and other fields. The products are sold all over the country and used in many national key projects. The development trend and factors of anti-corrosion spiral steel pipe company are as follows (1) The surface treatment of base iron must be Sa2.5 grade before coating. It is strictly forbidden to bring water, dust and oil in the construction to ensure the painting quality. (2) The proportion of coating is: component a (base material), component B (curing agent) = 9kg, paint: 1kg curing agent (or according to the proportion of our factory). (3) The construction proportioning method is as follows: open the big mouth of component A, add component B into component A, and fully mix it evenly. After 30 minutes of curing, coating can be carried out. (4) This material is required to be used at any time, and the coating must be used up within six hours after mixing. The unfinished materials should be sealed and stored. (5) Construction shall be stopped in rainy days or when the relative humidity is greater than 75%. For the parts with serious corrosive medium, it is recommended to apply multiple coats. (6) The product should be stored in a cool and dry place to prevent direct sunlight, keep away from fire source and heat source. (7) The storage period is 12 months. After the expiration of the storage period, the technical indicators shall be inspected. If the requirements are met, they can be used continuously.