Elemental Analysis of Steel using Eltra’s Combustion Analyzers

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.


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



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