Steel 20KH1M1F1BR (ЭП44)

  • Steel 20Х1М1Ф1БР (EP44)
  • Steel 25Х1М1ФА (Р2МА; 25Х1М1Ф)

    • Designation

    Name The value
    Designation GOST Cyrillic 20Х1М1Ф1БР
    Designation GOST Latin 20X1M1F1BP
    Transliteration 20H1M1F1BR
    By chemical elements 20Cr1Mo1V1NbB
    Name The value
    Designation GOST Cyrillic ЭП44
    Designation GOST Latin EP44
    Transliteration EhP44
    By chemical elements -

    Description

    20KH1M1F1BR steel is used: for the production of fasteners with special operating characteristics; fasteners turbines and flange connections, steam pipes and equipment and parts with operating temperature up to 500−580 °C.

    Note

    Steel pearlitic class.

    Standards

    Name Code Standards
    Sheets and strips В23 GOST 103-2006
    Bars and shapes В22 GOST 1133-71, GOST 2590-2006, GOST 2591-2006
    Sheets and strips В33 GOST 4405-75
    Bars and shapes В32 GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 20072-74, TU 14-1-552-72, TU 14-11-245-88

    Chemical composition

    Standard C S P Mn Cr Si Ni Fe Cu V B Ti Mo Nb W Ce
    GOST 20072-74 0.18-0.25 ≤0.03 ≤0.03 0.5-0.8 1-1.5 ≤0.37 ≤0.3 Rest - 0.7-1 ≤0.005 ≤0.06 0.8-1.1 0.05-0.15 ≤0.2 0.05-0.1
    TU 14-1-552-72 0.18-0.25 ≤0.03 ≤0.03 0.5-0.8 1-1.5 ≤0.37 ≤0.45 Rest ≤0.3 0.7-1 ≤0.005 ≤0.06 0.8-1.1 0.05-0.15 - 0.05-0.1
    Fe is the basis.
    According to GOST 20072-74, when steel is scrap-process, the content of Cu ≤ 0.30%. Tungsten is allowed up to 0.20%. When smelting steel by the method of electroslag remelting, the mass fraction of sulfur should not be more than 0.015%.
    According to TU 14-1-552-72, the chemical composition is given for steel grades 20Х1М1Ф1БР (ЭП44) and 20Х1М1Ф1БР-Ш (ЭП44-Ш).

    Mechanical properties

    Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2
    Bars hot rolled and forged (12-180 mm). Normalization at 1030-1050 °C, air cooling + Speed vacation: at 600 °C (extract 3 hours) at 700-720 °C (exposure 6 h), air cooling
    ≥670 ≥780 ≥14 ≥50 ≥590
    Rolled steel. Quenching in oil with 970-990 °C + Vacation 680-720 °C (exposure 6 h), air cooling
    ≥665 ≥780 ≥14 ≥50 ≥579

    Description mechanical marks

    Name Description
    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
    KCU Toughness

    Physical characteristics

    Temperature Е, HPa r, kg/m3 l, W/(m · °C)
    20 217 7900 -
    100 211 - 41
    200 205 - 461
    300 196 - 482
    400 188 - 502
    500 180 - 528
    600 167 - 544
    700 152 - 561

    A description of the physical symbols

    Name Description
    Е The normal elasticity modulus
    r Density
    l Coefficient of thermal conductivity
    R UD. the resistivity