Q235 steel is the most widely used in modern construction, so in addition to cheap, what are the good or bad properties of it?

Step 1: Application

It is widely used in ordinary concrete structures as hot-rolled round steel Q235. In ordinary concrete, Q235 steel is used as secondary reinforcement or scaffolding reinforcement, which is carbon structural steel. In addition, there is also a large number of hot-rolled ribbed steel bars in ordinary concrete, according to the "reinforced concrete ribbed steel" (GB1499) and the "Code for the design of concrete structures" (GB50010-2002) can be understood, its code name HRB335 or HRB400.

In reinforced concrete construction projects, Q235 steel is also used extensively in formwork. The composite template uses Q235 hot rolled steel plate, and its basic material thickness is 2.5~3mm; The all-steel large formwork uses hot rolled plate with grade Q235, and the thickness is 5~6mm.

A large number of non-essential steel frame structures use Q235 steel. Most of the steel supports in the project are made of steel pipes with a diameter of 48mm and the grade is Q235, and a small number of steel pipes with a diameter of 42mm are used to make portal and square tower brackets.

Step 2 Classify

Generally speaking, there are many classification methods of materials, such as the common classification methods according to strength, hardness, density, thermal conductivity, electrical conductivity, weldability, plasticity, strengthening and other material properties, in addition to the classification methods according to the process, such as material forming process, alloying process, heat treatment process, surface treatment process and so on. In addition, there are classification methods according to material acceptance conditions, mode of transportation, application scenarios, and so on. It can be noted that the classification of materials is very extensive, which is the concrete manifestation of the rich and colorful application of most materials, and material classification is also an important method for the application of materials in our life and work. Q235 steel as a very widely used steel material, what are the more important classifications of it?

It is a medium and low strength steel. Its yield strength is 235Mpa, the strength in steel materials is relatively low, higher than its strength steel such as Q345 is a medium strength steel, and then higher strength such as Q420D is a high strength steel, there are relatively special ultra-high strength steel such as GC-4 steel, its tensile strength of 1765~1961Mpa.

It belongs to carbon structural steel, and its composition is shown in the following table in GBT_700-2006_ Carbon structural steel. Carbon steel is iron, carbon two elements as the main composition of the alloy, but the carbon content is less than 2%, generally contains a small amount of silicon, manganese, sulfur, phosphorus and other elements, which according to the quality of the sulfur and phosphorus content of more than 0.35% but less than 0.5% carbon steel is called ordinary carbon steel, high quality carbon steel and high quality steel sulfur content are lower. The latter contains less than 0.3% sulfur and phosphorus.