Good afternoon, a short article from us about the types of steel and how they differ. This is a very small part of a large topic, but I hope it will put all the dots in perspective.
Types of steel for design
t is hard to imagine modern construction without the use of metal in the structural elements of beams, columns, and girders. Almost all buildings: houses, bridges, hangars, consist of steel structures. The main advantages of using a metal load-bearing frame are: it reduces the construction speed by up to 50%, the use of a more flexible form of the load-bearing frame, and reduced dimensions of load-bearing elements both in height and width. This gives an excellent balance of load-bearing
Let’s move on to the definition: steel is a metal consisting of iron (slightly more than 50%) and carbon (slightly more than 2.14%).
Steel is classified by:
Mechanical strength – ordinary, high, high.
- Ordinary – low-carbon in the range (C235 … C285).
They have medium corrosion resistance and brittleness at low temperatures;
- Alloys of increased strength are C345 … C390.
The characteristics depend on the amount and type of additional metals;
- High strength – such alloys have good fluidity, compression and ductility.
- Chemical composition – low-carbon, low-alloy and alloy steels.
- Low-carbon steels are ductile and weldable and are used in the construction industry.
- Low-alloy steels are characterized by high fluidity and corrosion resistance. These steels are used to make lightweight structures and are used in hydraulic engineering.
- Alloy steels – due to the content of 2.5% to 10% of additional elements in the composition, they improve the physical and chemical properties of the material.
According to the degree of deoxidation:
-Boiling (bb) – prone to rapid destruction, fragile.
Semi-quiescent (ps) – stable in operation;
-Calm (cc) – welds well and can withstand any load.
Marking of construction steels
“St” stands for construction steel;
The number indicates the amount of carbon in the alloy;
Letters “kp”, “ps”, “sp” at the end indicate the boiling type of deoxidation.
Steel is calm if there are no additional letters.
The ratio of steel grade and carbon content is shown in the table:
Sulfur content in carbon alloys is at least 0.045%, phosphorus content is at least 0.055%.
| Grade | Carbon contents, % |
| St 0 | Less than 0.23 |
| St 1 | 0,06-0,12 |
| St 2 | 0,09-0,15 |
| St 3 | 0,14-0,22 |
| St 4 | 0,18-0,27 |
| St 5 | 0,28-0,37 |
| St 6 | 0,38-0,49 |
| St 7 | 0,50-0,62 |
Marking of alloyed alloys
Consider the chemical elements present in alloy steels.
| Name | Chemical element | Designation |
| Chromium | Cr | Х |
| Silicon | Si | С |
| Titanium | Ti | Т |
| Copper | Cu | Д |
| Tungsten | Wo | В |
| Manganese | Mn | Г |
| Vanadium | V | Ф |
| Bor | B | Р |
| Nitrogen | N | А |
| Nickel | Ni | Н |
| Cobalt | Co | К |
| Molybdenum | Mo | М |
| Niobium | Nb | Б |
| Selenium | Se | Е |
| Zirconium | Zr | Ц |
| Aluminum | Al | Ю |
An example of a construction steel grade with alloying additives: 12G2S.
The designation is decoded as follows:
12 is the carbon content of the metal. In our case, it is 0.12%. If there is only one digit in the name, it should be taken as a hundredth of a percent;
M – the presence of manganese 2%;
S – silicon, about 1%;
There are many types of alloy construction steels.
Designation of structural steel
| Name | Brand |
| С 235 | Ст3кп2 |
| С245 | Ст3пс5, Ст3сп5 |
| С255 | Ст3Гпс, Ст3Гсп |
| С275 | Ст3пс |
| С285 | Ст3сп, Ст3Гсп,Ст3Гпс |
| С345 | 12Г2С, 09Г2С |
| С345Д | 12Г2СД, 09Г2СД |
| С345КС375 | 10ХНДП |
| С375Д | 12Г2С |
| С390 | 14Г2АФ |
| С390Д | 14Г2АФД |
| С390К | 15Г2АФДпс |
| С440 | 16Г2АФ |
| С440Д | 16Г2АФД |
| С590 | 12Г2СМФ |
| С590К | 12ГН2МФА10 |
The principles used for the designation of steel alloys were developed in Soviet times and are now used in Ukraine and the CIS.
Thank you for your attention and see you soon.