久久综合色鬼综合色丨免费无遮挡无码永久在线观看视频丨日韩精品无码一区二区中文字幕丨99久久久无码国产aaa精品丨性xxxx18免费观看视频

Development trend and factors of anti-corrosion SSAW steel pipe suppliers

There are some special corrosion forms in fresh water that affect the development trend and factors of anti-corrosion SSAW steel pipe suppliers, such as wear corrosion of metal components (such as power station turbine components and ship propeller, etc.) with large sediment content and high velocity in river water; metal acid corrosion caused by accumulation of microorganisms in lake water, etc. 2) Impact of fresh water corrosion The environmental factors such as pH value of water, concentration of dissolved oxygen, large diameter spiral steel pipe, other dissolved components and temperature, and fluxion have great influence on fresh water corrosion. ① The effect of pH value on Fe, Ni, Mg, CD and other metals, in different pH range, the relationship between corrosion rate and pH value has great changes. For example, in the range of pH = 4-9, the corrosion rate of steel The degree is basically stable and hardly changes with the pH value of water. This is because the corrosion of iron is controlled by the diffusion of oxygen. The hydroxide film formed during the corrosion of iron covers the surface of iron and steel, and oxygen can only depolarize through the film; 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 film dissolves   The corrosion rate increases with the increase of alkalinity, and when pH < 4, the membrane also dissolves, and the corrosion rate increases sharply with the increase of acidity. ② The content of dissolved oxygen in dissolved oxygen water is an important factor affecting corrosion. The corrosion rate of metal is in direct proportion to the concentration of dissolved oxygen under the condition of non passivation. When the content of dissolved oxygen exceeds the fixed value, the metal changes from active state to passive state As a result, the stability of the oxide film increases and the corrosion rate decreases sharply. However, in acid fresh water or high salinity fresh water, the increase of oxygen content can not passivate blunt metals such as aluminum, and the corrosion rate will still increase. The anti-corrosion SSAW steel pipe suppliers is widely used in petroleum, chemical industry, 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 to many national key projects all over the country. Development trend and factors of anti-corrosion SSAWsteel pipe suppliers: (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 coating ratio is: component a (base material), component B (curing agent) = 9kg paint: 1kg curing agent (or according to the proportion of construction informed by our factory). (3) The construction proportioning method is: open the large opening of component A, add component B into component A, and mix well. After 30 minutes of curing, coating can be carried out. (4) This material is required to be used with matching, and the coating after matching must be used up within six hours. Unfinished materials shall 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 brush several times. (6) The product shall be stored in a cool and dry place to prevent direct sunlight, isolate the fire source and keep away from the heat source. (7) The storage period is 12 months. After the expiration of the storage period, all technical indicators shall be inspected. If they meet the requirements, they can continue to be used.