Stamps and marking of stainless steel welding electrodes

Stainless steel welding electrodes are a type of welding electrode that is used in the welding of stainless steel materials. These electrodes are made of a stainless steel wire and are coated with a flux that provides shielding from the atmosphere, helping to stabilize the arc and prevent oxidation of the weld. In order to ensure that the electrodes are of the highest quality and suitable for the intended application, manufacturers must comply with strict standards and regulations.

One of the important ways to ensure the quality of stainless steel welding electrodes is through the use of stamps and markings. These stamps and markings are used to indicate the type of electrode, the manufacturer, the size and composition of the electrode, and the certifying agency. The stamps and markings also provide important information such as the recommended welding parameters and safety precautions.

The American Welding Society (AWS) is one of the leading certifying agencies for welding electrodes. They have developed a classification system for stainless steel welding electrodes, which is based on the type of coating, the type of stainless steel, and the position of welding. This system is used to classify and identify the electrodes, and it is reflected in the stamps and markings on the electrodes.

Classification of high alloy steel

Before starting the question of choosing stainless steel welding electrodes, it is necessary to determine the very concept of this material. Popular terminology divides all steel into two main classes - the considered stainless steel and the so-called.

• appearance - shiny stainless steel (although not always), without traces of scale and corrosion;
• viscosity and lower hardness, which are easily determined with a chisel, file, drill, hacksaw or abrasive wheel;
• A magnet test is also a popular method - stainless steel is not magnetized, which is also not always true.

The given luggage is obviously not enough to make such a critical joint as welded, it is also unacceptable to cover in one term a large group of steels classified by GOST as stainless.

[caption id="attachment_261" align="aligncenter" width="300"] Welding stainless steel[/caption]

Stainless steels include steels with the ability to work in corrosive environments, and this ability is determined by the presence of alloying elements, mainly chromium and nickel.

The official document regulating the classification of stainless steel is the interstate standard GOST 5632-14 . In accordance with its definitions, alloyed stainless steels include steels with a chromium content of at least 10.5% and a carbon content of no more than 1.2% and corrosion-resistant steels and alloys - which are resistant to all types of corrosion (chemical, electrochemical, intergranular stress corrosion, and others).

Stainless steel steps

The specific purpose and scope of steel are determined by its internal structure - the chemical composition and type of crystal lattice, which in turn also depends on the method of melting, heat treatment, and rolling. Without delving into the theory of metallurgy, we present the division of alloyed stainless steels into structural classes in accordance with GOST 5632-14:

• martensitic;
• martensitic-ferrite;
• ferrite;
• austenitic-martensitic;
• austenitic-ferritic;
• austenite.

The steel structure largely determines its technological quality , such as weldability. The presence of chromium in highly alloyed corrosion-resistant steels defines their characteristic concept of "intergranular corrosion". When welding at the boundary of heat-affected zones, granular structures of chromium carbide with reduced strength and a tendency to brittle fracture are formed. This quality largely determines the special requirements for the welding technology of these steels and welding materials for its application.

Stainless steel markings

[caption id="attachment_259" align="aligncenter" width="300"] stainless steel welding electrodes[/caption]

Joining the popular terminology - stainless steel - consider its designation in accordance with the requirements of GOST 5632-14. . The first two digits indicate the carbon content in percent, then the alloying element and its percentage are indicated sequentially. If there are no numbers behind the letter, then the content of the element does not exceed 1 percent.

Without listing all the chemical elements, we give some designations characteristic of stainless steels: X - chromium, H - nickel, T - titanium, B - tungsten, M - molybdenum. Nonmetals can also be alloying elements. In the designations of many steels according to GOST 5632-14, you can see the letters A - nitrogen, G - manganese, E - selenium.

As you can see, the designation of stainless steel carries information about its chemical composition, which mainly determines the chemical composition of the welding materials used.

Stainless steel welding

Since the topic of the article is stainless steel welding electrodes, two welding methods, the most common in the manufacture and installation of equipment, will be considered.

[caption id="attachment_260" align="aligncenter" width="300"] stainless steel welding electrode[/caption]

The first of these is manual argon arc welding (RADS). This is one of the types of welding in the shielding gas environment, the gas is an inert gas, argon. The welding arc is created by a non-consumable tungsten electrode with a diameter of 1.6 to 4.0 mm, and the welding pool is filled with filler wire of the appropriate grade. This welding method is most common precisely when welding stainless steel.

The most common, widely known, and practically universal method is manual arc welding with a consumable electrode (RDS) . The word "electrode" is mainly associated with this particular method.

The variety of stainless steel brands in chemical composition determines the variety of types and brands of electrodes for its welding according to the same principle. GOST 5632-14 classifies more than one hundred grades of highly alloyed steels.

The main types of electrodes, literally "coated metal electrodes for manual arc welding of highly alloyed steels with special properties" are established by another standard - GOST 10052–75. Its classification includes 49 types of electrodes. The designation of electrode types begins with the letter E and a dash, followed by an indication of the carbon content and alloying elements that we have already considered.

Welding electrode marking

GOST 10052–75 precisely defines the types of electrodes according to the chemical composition of the metal rod .

In practice, they usually operate on the concept of the electrode brand, which depends on its manufacturer. The same type may be produced under different brands, with the manufacturer confirming that his brand of stainless steel electrodes conforms to the type and requirements of the standard.

The marking of the electrodes must contain information about the brand and type of the electrode, its diameter, type of coating, mechanical characteristics of the connection made, the permissible spatial positions, the type of current - alternating or direct and its polarity - direct or reverse. For responsible work in the production, assembly, installation or repair of equipment, the brand of electrodes is determined by specialists - designers or technologists.

Which electrode to choose for welding stainless steel for domestic or household needs - making a barbecue or home smoking, a sewage drain pipe or a car exhaust pipe - help from technical literature or from the Internet will help. True, this information will be useful provided that there is information about the steel grade itself.

Stainless Steel Welding Electrodes Brands

The most common in use and known by many brands are corrosion-resistant steels of the austenitic class - 08X18H10, 08X8H10T, 12X18H10T. Many people know the brand of electrodes for their welding - EA-400 / 10T or EA / 400 / 10U. This brand corresponds to type E-07X19H11M3G2F according to GOST 10052–75. They are used for welding pipes of any diameter, in the production of containers and vessels with an operating temperature of up to 350 ° C. TsL-11 brand electrodes correspond to the same type. They are used for welding products operating in an aggressive environment with temperatures up to 400 ° C.

Other brands of electrodes are used for welding austenitic-grade steels. In mechanical engineering, OZL-8 brand electrodes are often used. They correspond to type E-07X20H9, with their help weld structures in the absence of strict requirements for resistance to intergranular corrosion. For products operating in an oxidizing environment with temperatures up to 650 ° C, grades CT-15 and ZIO-3 corresponding to type E-08X19H10G2B are used.

Both in the energy sector and in the food industry, corrosion-resistant chromium steels of martensitic, martensitic-ferritic and ferritic grades - 08X13, 12X13, 20X13 - are widely used. The working temperature of their parts and structures reaches 600-650 ° C. Their welding is carried out with E-12X13 type electrodes of the UONI-13 / NZh 12X13 brand.

Corrosion-resistant and heat-resistant steels of the same grades 12X17, 08X17T are welded with electrodes of the E-10X17T type of the UONI-13 / NZh 10X17T brand. The heat resistance of the welded joint reaches 800 ° C.

Conclusion

In conclusion, the quality of stainless steel welding electrodes is crucial for achieving the desired results in terms of the strength and durability of the weld.

Manufacturers must comply with strict standards and regulations to ensure that the electrodes are of the highest quality and suitable for the intended application.

These stamps and markings provide important information about the type of electrode, the manufacturer, the size and composition of the electrode, and the certifying agency. They also provide recommended welding parameters and safety precautions.