The S275 steels are structural steels with a low carbon content and are also known as "construction steels", as they are mainly used in the construction of building works.
Given the percentage of carbon present in its chemical composition, this alloy, in fact, can be easily formed, bent and welded, as the heat treatments do not affect its microstructure and the resistance of the material.
Small amounts of alloying elements, such as manganese, sulphur, phosphorus and silicon, can be added to the composition of S275 steel to give the alloy certain mechanical properties or enhance those already present.
Within the main class, different types of S275 steel can be identified, distinguished by the additional letters and numbers J0, JR, AR, J2 E N. These specifications indicate some characteristics of the steel, such as the relationship between resilience and temperature or the state of rolling.
These properties can be combined with each other, therefore structural steels are identified that have a certain guarantee of resilience at a certain temperature and can be rolled in their natural state or by normalization (therefore when hot).
S275 J0 steel has a guarantee of resilience at 0°C> 27J, while s275JR steel has, when required, a guarantee of resilience at a temperature greater than 20°C> 27J.
Characteristics deriving from the state of rolling can then be applied to these specifications, which will be natural in the case of S275JR+AR and S275J0+AR steels, while it will be derived from hot rolling in the case of S275JR+N steel.
Then there is the S275J2+N steel, which has a guarantee of resilience at 20°C> 27J and a rolling determined by heat treatment.
S275 steels are mainly used in the construction of infrastructures, such as bridges, and in the construction of buildings, but they are also used in the production of components for the automotive and oil & gas sectors.
The choice between these structural steels therefore depends exclusively on the temperatures that the structures will have to tolerate and on the degree of resilience required.
