Steel 10ГН (10ГНА)
|Designation GOST Cyrillic||10ГН|
|Designation GOST Latin||10GH|
|By chemical elements||10MnН|
|Designation GOST Cyrillic||10ГНА|
|Designation GOST Latin||10GHA|
|By chemical elements||10MnН|
10ГН steel is used: for the production of hot-rolled billets used for the manufacture of seamless hot-rolled tubes; welding wire of SV-10ГН required for submerged arc welding of structures with special requirements for performance and corrosion resistance of the welds.
Mild steel, timeless steel capped aluminum.
|Blanks. Of the workpiece. Slabs||В31||TU 14-1-1251-75, TU 14-1-1365-75, TU 14-1-2376-78|
|Steel pipes and fittings to them||В62||TU 14-3-369-75, TU 14-3-626-77|
According to TU 14-1-1251-75 and TU 14-1-1365-75 the chemical composition is presented for steel grade 10GN. In the pipe billet, deviations in the chemical composition from the regulated are allowed: for carbon ± 0.010%, for manganese ± 0.10%, for silicon ± 0.10%, for nickel ± 0.050%, for sulfur +0.005%, for phosphorus +0.005% , for copper +0,10%, for chromium +0,050%.
According to TU 14-1-2376-78, the chemical composition is presented for high-grade 10GNA steel. Deviations in chemical composition are allowed: carbon ± 0.010%, manganese ± 0.10%, silicon ± 0.10%, nickel ± 0.050%, sulfur +0.005%, phosphorus +0.005%, copper +0 , 10%, chromium + 0.05%.
|Section, mm||σU, MPa||d5, %||KCU, kJ/m2|
|Steel hot-rolled in circles on THAT 14-1-2376-78 (in the graph of impact strength values in the direction of rolling / across the direction of rolling)|
Description mechanical marks
|sT|s0,2||Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%|
|σU||Limit short-term strength|
|d5||Elongation after rupture|
|y||The relative narrowing|
|Macrostructure and pollution||On the other 14-1-1251-75 the 14-1-1365-75 macrostructure of billets when checking for cross etched Templeton in the delivered profile should not have shrinkage porosity, bubbles, cracks, inclusions, inversions, bundles and placenow visible without using the magnifying devices. The defects allowed must not exceed the following standards: - point nonuniformity ≤ 3 points; Central porosity ≤ 2 points; - exudation square ≤ 3 points. Contamination of metal non-metallic inclusions shall not exceed: - sulphides ≤ 4 points; - in the oxides and silicates of ≤ 4 points. Control of macrostructure on the other 14-1-2376-78 produce after deep etching in a fifty percent aqueous solution of hydrochloric acid (density 1,19 g/cm3) at a temperature of 60-70 °C for 20-25 minutes. The value of the segregated Central square and the porosity is determined by comparison with the scale of the application 1. On the cut surface of the circles on the other 14-1-2376-78 not allowed defects: delamination, bubbles and other defects of the macrostructure. The macrostructure is not allowed discontinuity of metal in the form of bundles, remnants of the shrinkage porosity and other serious defects. The degree of development of the Central porosity and phase separation of the square should not exceed given in the references (Annex 1 to THAT 14-1-2376-78). Non-metallic inclusions in steel on the other 14-1-2376-78, oxides and sulfides should not exceed 3.5 points on a scale GOST 1778. It is possible to supply up to 20 % of the steel with a content of oxides and sulphides of not more than 4th grade.|
|Microstructure||Microstructure of steel on the other 14-1-2376-78 should consist of grains of ferrite and sarbatoarea or granular pearlite, located as uniformly as possible. The grain size of the ferrite may be in the range of 7-10 points according to GOST 5639, the maximum size of individual grains may be no more than 0.07 mm., the uniformity of distribution of cement shall conform to the standards (Annex 2 to THAT 14-1-2376-78). Banding of ferrite-pearlite structure should not exceed the 4 point scale (Annex 2 to THAT 14-1-2376-78). The depth of the zone of complete decarburization on each side should not exceed 0.3 mm, considering the border at the first grains of cementite.|
|Particularities of production of goods||Mugs from hot rolled high quality steel supplied on THAT 14-1-2376-78 in the heat-treated condition (quenching and tempering) and etched surface.|