The appearance of stainless steel we owe to engineer Harry Brearly. By adding a chemical element called chromium to the metal, he tried to achieve an increase in the melting point. This was required to improve the performance of artillery barrels. During such experiments, it turned out that the resulting alloy has differences compared to others. They are resistant to chemical attack. This is due to the formation of chromium oxide on the surface of the film .
Research on stainless steel began in 1871, and the first patent was registered only in 1913. A modern analogue of stainless steel, which meets all the requirements for strength and chemical properties, was obtained in 1924 by a scientist named Hartfield.
Stainless Steel Basics
In reference books or other literature, corrosion-resistant steel has the following designation: "steel grade 08X18H10." This means the content of the following elements:
- carbon - not more than 0.8%;
- chromium - 18%;
- nickel - 10%.
These are the main chemical elements, but other inclusions are also present in the alloy, their percentage does not exceed 1%.
Main stainless steel products
Such corrosion-resistant products are made of corrosion-resistant steel as:
- stainless wire;
- Sheet steel;
- pipes of various wall thickness and internal diameter;
- profiled products.
Also, many household knives and knots of food processors are made of this material.
Stainless steel wire
Like any other metallurgical product, wire is produced in accordance with current Russian standards.
Regulates the production of such material as stainless wire, GOST 18143-72. According to this document, it has a thickness of 0.3 to 6 millimeters.
Such a wire can be used as a final product and can be further processed by molding. Then from it you can get:
- chains with different link sizes,
- mesh with different cell spacing,
- springs.
The cross section of such a wire is usually round, but you can also find oval or square shapes. The round section is very convenient when using the material in the welding process of the same stainless steel.
Stainless steel wire has the following main advantages:
- high rates of corrosion resistance to moisture, aggressive industrial environments and condensate;
- A wire with a high content of molybdenum, chromium, nickel, copper, silicon, vanadium has high heat resistance, reliability and durability.
Stainless wire application
Due to the long service life, resistance to acid and alkaline environments, stainless steel wire has been widely used in two directions:
- knitting in ropes;
- welding work;
- mesh weaving for filters.
Stainless steel wire, the price of which varies from 120 to 350 rubles per kilogram, depending on the thickness and features, has been widely used in industries such as:
- machine-building;
- electric power industry;
- oil;
- chemical;
- food.
Welding wire
The widespread development of the chemical industry required metallurgists to create a metal capable of maintaining high mechanical properties in aggressive environments. In addition to resistance to various chemical elements, some industries also require properties by which the metal can withstand the effects of high temperatures. Stainless steel solves many of the tasks. In addition, the use in the food industry of another material is impossible.
The modern level of processing of metal products allows us to produce complex products, but with all this, you can not do without welding joints. Corrosion-proof wire is used to weld products in complex assemblies that are exposed to aggressive environments.
The main advantage possessed by stainless welding wire is that when it is used, the weld is almost clean, without harmful toxins and spurious inclusions. Thanks to the use of stainless steel material, the seam itself is not susceptible to oxidation. The payback for such advantages is that the welding process in this case is quite complicated, and consumables are expensive.
Stainless steel wire is used only in automatic welding. It is fed by an automatic feeder, current is passed through it.
The protective gas enters the arc zone, which displaces the oxidizing agents, due to this, the weld is completely cut out and all components are joined.
Welding wire is wound into a steel drum with a continuous length of up to 50 meters. The average diameter of the drum is 50 millimeters. The wire feed from the spindle is carried out by the rotation of two clamping coils. Slanting grooves are cut in the middle, with the help of which there is a reliable grip of the wire and its feeding to the welding gun. Before winding the stainless wire, it is thoroughly cleaned of dirt and impurities.
Welding wire marking
The wire is made by cold rolling and hot working. It has two types of accuracy - normal and high. In the latter case, after marking, the letter P is put in parentheses
Stainless steel wire has two main markings - domestic and foreign.
The Russian marking has an alphanumeric look - 10X17H13M2T. The following order of letters and numbers means its internal structure and chemical composition. The numbers determine the percentage composition of an element, and the letter determines the element itself. The above abbreviation is deciphered as follows:
- 0.1% carbon;
- chromium - 17%;
- nickel - 13%
- Manganese - 2%
- the letter T means that the wire is produced by heat treatment.
The European standard is rather complicated and does not have a single marking according to the norms. Each steel manufacturer patents its composition.