Analysis of large caliber seamless tube structure and its chemical activity

When the large-caliber seamless pipe is in contact with the surrounding electrolyte solution, the corrosion caused by electrochemical action is called electrochemical corrosion. The so-called electrochemical action, that is, in the chemical reaction process produced the action of electric current. This kind of corrosion due to the generation of electric current is electrochemical corrosion. It is more common than chemical corrosion. Generally speaking, the electrochemical corrosion principle of large-caliber seamless tube is the same as that of large-caliber seamless tube primary cell. Therefore, in order to understand electrochemical corrosion, we must first learn the theory of primary cell and relevant knowledge.

I. structure and chemical activity of large-caliber seamless tube

From the modern theory of atomic structure, because of the large diameter seamless pipe less number of the outermost electrons in an atom (1, 2, 3 e e e), and with the increase of atomic radius, the outermost electron is very easy to lose. When electrons from off of large diameter seamless tube atom, large-diameter seamless pipe atom becomes a large diameter seamless pipe cation, and when the electrons and large diameter seamless pipe cation, has now become a neutral large-diameter seamless tube atom.

With X-ray for large diameter seamless pipe structure research result has proved that all of large diameter seamless pipe with crystal structure, on the large diameter seamless pipe crystal lattice site lined with large diameter seamless pipe and large diameter seamless pipe cationic atom. In the original to and ion exists between off from the atomic electrons, these electrons are not fixed in a large diameter seamless pipe lattice nodes nearby, but in the entire character intercropping of freedom of movement, therefore calls free electrons. Due to free electron movement produced large-diameter seamless tube, with the aid of large diameter steel pipe keys, atoms and cationic large-diameter seamless tube to closely link together to form the large diameter seamless pipe crystal. Because of the above structural characteristics, especially the existence and motion of free electrons, large caliber seamless pipe has some common properties. Such as conduction, heat transfer, malleability and so on. In chemical properties, large caliber seamless tube atoms are easy to lose their valence electrons and become cation. Therefore, large caliber seamless tube is reducing agent. The more easily large seamless tubes lose electrons, the more chemically active they become.

For example, if we put a small piece of zinc into any solution of lead salts, we can see that zinc begins to dissolve, and lead dissolves from the solution. Such as:

Zri + Pb (N03) 2 = Pb + zinc (N03) 2

Write it as an ion equation:

Zinc + Pb++ = Pb + Zn++

Obviously, this is a typical REDOX reaction. The essence of the reaction is that the zinc atom gives its outermost electron to the Pb++ ion, which becomes Zn++ + ion and enters the solution. Pb++ + ions, on the other hand, combine with electrons to form large seamless tubes of lead that precipitate out of the solution. If you do the opposite experiment, you put a small piece of lead in a zinc salt solution roll, and nothing happens. This means that zinc is more likely to lose electrons than lead, and zinc ions are less likely to bind electrons than lead. So zinc is more active than lead.

If use the same method to compare the lively of lead and copper, found that lead than copper and lively, which lead to replace the steel from the salt solution, and the copper is not a lead from the salt solution of displacement.

It can be seen that of the three kinds of large-caliber seamless tubes mentioned above -- zinc, lead and copper -- zinc is the most active, losing electrons the most, lead the second and copper the least. According to the above experiments, the size of the mutual substitution ability of large-caliber seamless tubes in solution, i.e., the size of the activity of large-caliber seamless tubes, can be determined.

Large caliber seamless tube activation sequence table

K, Na, Ca, Mg, Ba, Al, Mn, zinc, Cr, Fe, Ni, Sn, Pb, H, Cu, Hg, Ag, Pt, Au

The ability of large caliber seamless tube to lose electron in solution (the activity and reduction of large caliber seamless tube) is weakened

From this sequence table, we can summarize the following chemical properties of large-caliber seamless tubes:

1. Each of the large caliber seamless tubes (including hydrogen) in the large aperture seamless tube activation sequence table can replace the large caliber seamless tube behind it from its salt solution:.

2. The large-caliber thick wall tube in front of hydrogen can replace hydrogen from dilute acid, while the large-caliber seamless tube behind hydrogen cannot.

3. In the sequence table, the more active the large-caliber seamless tube in front of it, the more likely its atoms are to lose electrons, and the more difficult its ions are to combine electrons and be reduced to large-caliber seamless tubes.