Steel Х56
Designation
Description
Х56 steel is used: for the manufacture of electric-welded longitudinal pipes ekspandirovannogo increased corrosion resistance and cold-resistance, used for pipelines, process and field pipelines for operating pressure up to 7.4 MPa to transport crude oil and petroleum products, pipelines of formation pressure maintenance in any climatic zones.
Standards
Chemical composition
Fe is the basis.
According to TU 1381-116-00186654-2013 the chemical composition is given for steel grade X56. The mass fraction of calcium in the steel should not be more than 0.0050% (50ppm) (optional). For globularization of inclusions, steel is treated with calcium-containing materials. The alloying of REM steel is allowed. The ratio of Ca / S is not less than 1. It is possible to add titanium from the calculation of the mass fraction in steel no more than 0.030%. Steel should be subjected to vacuum degassing: the mass fraction of hydrogen in the liquid steel after degassing should be no more than 2ppm. The mass fraction of hydrogen is taken from the document on the quality of rolled sheets. If the hydrogen content is more than 2ppm, the slabs should be subjected to anti-flock treatment (PFD) in heated or unheated rings. The mass fraction of Nb + V is not more than 0.15%. In the steel, the carbon content is allowed up to 0.14% in an amount not exceeding 15% of the order quantity. Permissible deviations in chemical composition: carbon + 0.010%, manganese + 0.020%, silicon ± 0.050%, sulfur + 0.0010%, phosphorus + 0.0030%, aluminum + 0.010%, copper +0.050 % by nickel +0,050, by chromium ± 0,050%, by vanadium + 0,020%, by nitrogen + 0,0010%. The carbon equivalent value should not exceed 0.43, and the resistance parameter against cracking P cm should not exceed 0.25.
According to TU 1381-116-00186654-2013 the chemical composition is given for steel grade X56. The mass fraction of calcium in the steel should not be more than 0.0050% (50ppm) (optional). For globularization of inclusions, steel is treated with calcium-containing materials. The alloying of REM steel is allowed. The ratio of Ca / S is not less than 1. It is possible to add titanium from the calculation of the mass fraction in steel no more than 0.030%. Steel should be subjected to vacuum degassing: the mass fraction of hydrogen in the liquid steel after degassing should be no more than 2ppm. The mass fraction of hydrogen is taken from the document on the quality of rolled sheets. If the hydrogen content is more than 2ppm, the slabs should be subjected to anti-flock treatment (PFD) in heated or unheated rings. The mass fraction of Nb + V is not more than 0.15%. In the steel, the carbon content is allowed up to 0.14% in an amount not exceeding 15% of the order quantity. Permissible deviations in chemical composition: carbon + 0.010%, manganese + 0.020%, silicon ± 0.050%, sulfur + 0.0010%, phosphorus + 0.0030%, aluminum + 0.010%, copper +0.050 % by nickel +0,050, by chromium ± 0,050%, by vanadium + 0,020%, by nitrogen + 0,0010%. The carbon equivalent value should not exceed 0.43, and the resistance parameter against cracking P cm should not exceed 0.25.