Basic Chemical Engineering Knowledge: [One Question per Day] 2011-01-13
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Short-answer question: Generally speaking, metal corrosion prevention is of great significance in industrial production. Corrosion prevention involves taking various measures to protect metal items prone to rusting, thereby extending their service life. Please list several common methods for preventing metal corrosion. PS:: 1) The top 50 active participants will definitely receive rewards. Those who provide a detailed process and reasoning will be awarded 1–15 wealth points :victory:. 2) Please hide your replies. The method to do this is: http://bbs.hcbbs.com/thread-492556-1-1.html. Do not edit your replies after posting them{:1_90:}, and also avoid copying others’ answers, as that will result in a deduction of points:funk: ； When answering, indicate the question number; otherwise, it’s difficult to determine whether the answer is correct or not: handshake. 3) The reference answers can be seen upon replying. Please refer to them if you want to confirm the answers, dear users :o. 4) Please also avoid submitting answers maliciously multiple times; if it is due to an operational error, please contact the forum moderators or administrators: call:. Otherwise, points will be deducted. 5) Currently, all the daily questions in the section on basic chemical engineering theories have been compiled; interested users can go and take a look and learn from them*. Click directly: Summary post of daily questions in the section on basic theories of chemical engineering (being added). Physical corrosion protection, chemical corrosion protection, and electrochemical corrosion protection are commonly used methods for protecting metals from corrosion. For example, various corrosion-resistant alloys are manufactured, such as stainless steel produced by adding chromium, nickel, and other elements to ordinary steel. A protective layer is applied to the metal surface to isolate the metal product from the surrounding corrosive agents, thereby preventing corrosion. For example: 1. Coat the surface of steel parts with engine oil, vaseline, paint, or cover them with corrosion-resistant non-metallic materials such as enamel or plastic. 2. Using methods such as electroplating, hot-dipping, and spray coating, a layer of metal that is resistant to corrosion—such as zinc, tin, chromium, nickel, etc.—is applied to the surface of steel. These metals often form a dense oxide film due to oxidation, which prevents substances such as water and air from corroding the steel. 3. Use chemical methods to form a fine and stable oxide film on the surface of steel. Such as the formation of a fine black film of iron oxide on the surface of steel components like machine parts and firearms. Metal protection is achieved by utilizing the principle of galvanic cells, with the aim of eliminating the galvanic cell reactions that cause electrochemical corrosion. Electrochemical protection methods are divided into two main categories: anodic protection and cathodic protection. The most commonly applied method is cathodic protection. Eliminate corrosive agents by regularly wiping metal equipment clean, placing desiccants in precision instruments, and adding small amounts of corrosion inhibitors to corrosive environments to slow down the rate of corrosion. Metal protection is achieved by utilizing the principle of galvanic cells, with the aim of eliminating the galvanic cell reactions that cause electrochemical corrosion. Electrochemical protection methods are divided into two main categories: anodic protection and cathodic protection. The most commonly applied method is cathodic protection.
The last edit to this post was made by yunzhongzi112 on 2011-1-12 at 23:48. 1. External anti-corrosion treatment for ordinary industrial metal pipes: After rust removal, either manually or mechanically, two coats of primer are typically applied – the primer used is red lead anti-rust paint – and thereafter, topcoats of different colors are applied depending on the type of medium involved； 2. For buried pipelines, an appropriate anti-corrosion coating is selected based on the degree of soil corrosion; common options include petroleum asphalt and epoxy coal tar pitch.
3. For internal anti-corrosion treatment of equipment, the anti-corrosion solution is chosen according to the corrosiveness of the medium inside the equipment. For instance, for steel wet gas holders, ethylene phosphating primer and epoxy coal tar pitch are used for anti-corrosion purposes. Forget to hide content; edit once
3. For internal anti-corrosion treatment of equipment, the anti-corrosion solution is chosen according to the corrosiveness of the medium inside the equipment. For instance, for steel wet gas holders, ethylene phosphating primer and epoxy coal tar pitch are used for anti-corrosion purposes. Forget to hide content; edit once
I. Surface protection: Surface coating: paint, grease, plastics, enamel, etc.; using electric, thermal, or spray-coated corrosion-resistant metals on the surface; forming a corrosion-resistant film through electrochemical methods on the surface. II. Electrochemical protection: anodic and cathodic protection
1. Structural modification method for metal corrosion protection 2. Protective coating method for metal corrosion protection 3. Electrochemical protection method for metal corrosion protection 4. Corrosion medium treatment method for metal corrosion protection
Methods include: protective coating methods, electrochemical protection methods (including sacrificial anode protection and impressed current protection), treating the corrosive medium, and altering the internal microstructure of the metal
Apply rust-proof paint. Industrial enamel. Fluoroplastic spraying. Electroplating, fire plating. Fiberglass resin coating. Other corrosion-resistant linings.
Changing the internal structural structure of metals] For example, various corrosion-resistant alloys are manufactured by adding elements such as chromium and nickel to ordinary steel to create stainless steel. A protective layer is applied to the metal surface to isolate the metal product from the surrounding corrosive agents, thereby preventing corrosion. For example: 1. Coat the surface of steel parts with engine oil, vaseline, paint, or cover them with corrosion-resistant non-metallic materials such as enamel or plastic. 2. Using methods such as electroplating, hot-dipping, and spray coating, a layer of metal that is resistant to corrosion—such as zinc, tin, chromium, nickel, etc.—is applied to the surface of steel. These metals often form a dense oxide film due to oxidation, which prevents substances such as water and air from corroding the steel. 3. Use chemical methods to form a fine and stable oxide film on the surface of steel. Such as the formation of a fine black film of iron oxide on the surface of steel components like machine parts and firearms. Metal protection is achieved by utilizing the principle of galvanic cells, with the aim of eliminating the galvanic cell reactions that cause electrochemical corrosion. Electrochemical protection methods are divided into two main categories: anodic protection and cathodic protection. The most commonly applied method is cathodic protection. Eliminate corrosive agents by regularly wiping metal equipment clean, placing desiccants in precision instruments, and adding small amounts of corrosion inhibitors to corrosive environments to slow down the rate of corrosion. Edit this section: Electrochemical protection The metal to be protected is used as the cathode in a corrosion cell, thereby preventing it from corroding; this method is also known as cathodic protection. There are mainly two such methods: In this approach, a reactive metal (such as zinc or an alloy of zinc) is connected to the metal that is to be protected. When electrochemical corrosion occurs, this reactive metal acts as the negative electrode and undergoes oxidation, thereby reducing or preventing corrosion of the metal being protected. This method is often used to protect steel piles and ship hulls in water, as well as items such as steel gates in aquatic environments. Typically, several zinc blocks are welded to the part of the ship’s hull below the waterline or to the rudder near the propeller, in order to prevent corrosion of the hull and other components. Connect the metal to be protected to the negative pole of the power supply, and connect another piece of conductive inert material to the positive pole of the power supply. When energized, it causes an accumulation of negative charges (electrons) on the metal surface, thereby preventing the metal from losing electrons and achieving a protective effect. This method is mainly used to prevent metal equipment in soil, seawater, and river water from corroding. Another method of electrochemical protection is called anodic protection, which involves applying an external voltage to cause the anode to enter a state of passivation within a certain potential range. It can effectively inhibit or prevent metal equipment from corroding in acids, alkalis, and salts.
Common methods include metal painting/coating, cathodic protection, sacrificial anode protection, and current-driven protection; that seems to be it
Deaerators are installed in the pipes leading to the boiler to remove oxygen from the desalinated water and prevent corrosion； The carbon steel pipes are sandblasted to remove rust, and anti-rust paint is applied to their surface
Structural modification methods for metal corrosion protection, protective coating methods for metal corrosion protection, electrochemical protection methods for corrosion prevention, and methods for treating corrosive agents in metal corrosion protection
Apply rust-proof paint. Industrial enamel. Fluoroplastic spraying. Electroplating, fire plating. Fiberglass resin coating. Other corrosion-resistant linings.