The essential stations of steel production are the blast furnace, converter and finishing. After each step the determination of the Carbon, Hydrogen, Nitrogen, Sulfur and Oxygen content is required for quality control. In the blast furnace pig iron is produced from iron ore, coke, and lime, along with the by-product slag. The burning of coke generates temperatures of up to 1,400°C inside the blast furnace, which is 30 to 50 metres high. At this temperature, iron ore liquefies and is at the same time checmically reduced through the carbon monoxide coming from the coke.
At the end of this process the pig iron still has a very high carbon content of up to 7% which is reduced in the convertor where scrap metal and, if required, more lime is added. Oygen is introduced which substantially reduces the existing carbon content by forming gaseous CO2. After this oxidizing process the iron melt can be alloyed with other metals (e.g chrome, nickel, vanadium, cobalt). Finally, this melt is used to produce the end product.
BLAST FURNACE | CONVERTER | FINISHING | |
Product to be analyzed | iron ore, lime, coke, slag | pig iron, scrap metal, lime | alloyed metals, steel |
Intermediate product | pig iron
Carbon: 4 – 7% Sulfur: 0.1 – 0.3% |
semi-finished products
Carbon: 10ppm – 1% Sulfur: 10ppm – 0.4% Nitrogen: 10ppm – 0.6% Oxygen: 5 – 1000ppm |
steel/stainless steel
Carbon: 10ppm – 1% Sulfur: 10ppm – 0.4% Nitrogen: 10ppm – 0.6% Oxygen: 5 – 1000ppm Hydrogen: 0.2 – 10ppm |
Analyzers | CS-2000, CS-800, CHS-580 | ONH-2000, CS-800 | ONH-2000, H-500
CS-800 |
Measurements Results Steel – Analyzed with Eltra’s ONH-2000
Elements | Steel(1) | Steel (2) | Steel (3) |
Nitrogen (ppm) | 530 ± 9 | 27 ± 2 | 118 ± 3 |
Oxygen (ppm) | 45 ± 3 | 12 ± 2 | 244 ± 5 |
Hydrogen (ppm) | 3.4 ± 0.3 | 1.9 ± 0.2 | 5.1 ± 0.4 |
Typical Weight | 1000mg | 1000mg | 1000mg |
Elements and Steel Properties
Carbon – Hardness, forgeability
Sulfur – Ductility
Nitrogen: Ductility
Oxygen: Corrosion tendency
Hydrogen: Brittleness