Metallographic diagram of 20 steel (submerged arc welding)

20 Steel (Submerged Arc Welding) Metallography

20 Steel (Submerged Arc Welding) metallography is the study of the microstructure of metals. The technique involves taking a sample from the metal being investigated and using a microscope to study its structure. In the case of welding, the samples are taken from two different locations: the base metal, as well as the weldment. The objective of the weldment sample is to analyse the quality of the weld.

The microstructure of the 20 Steel (Submerged Arc Welding) material will be observed through a microscope, looking at both the macro and micro level. On the macro level, the morphology of the welded material (including the overall shape and size of the weld) can be observed. On the micro level, the chemical composition, grain structure and grain size, as well as the presence of annealing and tempering, can be determined.

The presence and amount of hydrogen, moisture and sulfur are important elements in the quality of welding. Low levels of these elements can cause porosity, cracking and reduced strength of the welded joint. The weld is also susceptible to contamination from ferrous and non-ferrous particles, which can affect the strength and the stability of the weld.

Detailed metallographic studies of the 20 Steel (Submerged Arc Welding) material can help determine the quality of the welding. By observing welding parameters, including the amount of heat input, the temperature at which the welding operation takes place, and the voltage used, it is possible to determine the effectiveness of the welding job. The rate of cooling from the welding process can also be observed, which is important in terms of the strength, ductility, and impact resistance of the weld.

20 Steel (Submerged Arc Welding) sampling can also be done to determine the strength of the weldment. This information is obtained by examining the frequency and size of grain boundaries, which allow for an evaluation of the strength of the weldment. This type of study also helps to determine the presence of porosity, as well as other structural imperfections.

In order to gain a better understanding of the weldment, 20 Steel (Submerged Arc Welding) metallography is a valuable tool. By examining the microstructure of the material, it is possible to not only determine the quality of the weldment, but also identify potential problems that can cause failures in the future. Detailed analysis of the welds, such as assessing the quality of the welds, or microstructural characteristics, can help to prevent potential problems before they become serious.

GB20 Steel Microstructure

GB20 steel is a low carbon steel commonly used in construction. It has superior weldability and bendability, as well as good machinability.

The microstructure of GB20 steel is mainly composed of a ferritic matrix with a certain amount of pearlite. Fine primary carbides exist in the matrix, and pearlite can be found along grain boundaries. The primary carbides are mostly ferrite and iron carbide (Fe3C). The pearlite is a combination of iron carbide and ferrite.

The microstructure of GB20 steel welded by arc welding is mainly composed of ferrite and pearlite. The presence of ferrite, pearlite and iron carbide makes the material easy to be bent and welded. The weld metal has homogeneous grain boundaries, and the thermal effect of welding can cause local segregation of alloying elements. The weld parts have low strength and toughness but good ductility.

The microstructure of GB20 steel has good machinability and weldability. The part structure is homogeneous, and the hardness and strength are consistent across the material. The part structure can be adjusted to achieve the desired properties by controlling the tempering temperature and duration. It also exhibits good corrosion resistance properties due to the presence of pearlite as well as other alloying elements.

In conclusion, GB20 steel is a low carbon steel that is commonly used in construction. Its microstructure is composed of a ferritic matrix with a certain amount of pearlite, fine primary carbides, and iron carbide. It has good machinability, weldability, and corrosion resistance.