Steel U8A

  • U16 steel (EI336)
  • U9A steel
  • U9 steel
  • U8GA steel
  • U8G steel
  • U8A steel
  • U8 steel
  • U7A steel
  • U7 steel
  • U12A steel
  • U12 steel
  • U11A steel (U11)
  • U10A steel
  • U10 steel
  • Steel AU10E (ASU10E)
  • A85 steel
  • Steel A75 (U7AB)

    • Designation

    Name The value
    Designation GOST Cyrillic У8А
    Designation GOST Latin U8A
    Transliteration U8A
    By chemical elements 8

    Description

    U8A steel is used: for the manufacture of tools, working in conditions without heating of cutting edge; the tool for tree processing (milling cutters, countersinks, zekovic, axes, chisels, chisels, longitudinal, and circular saws; rollers, plates and rods for mold molding tin-swinomish alloys; calibers simple form and low accuracy classes; cold-rolled heat-treated ribbon with a thickness of from 2.5 to 0.02 mm, intended for manufacturing of flat and wire springs and spring-loaded parts of complex configuration (valves, styli, reeds, slats dolnych knives structural fine details, including hours, etc. (tape is produced according to GOST 2283, GOST 21996 and a number of special technical conditions); cold-rolled heat-treated ribbon with a thickness of 0.05 to 1.30 mm and rolled heat-treated strip thickness 0.15−2.00 mm for the manufacture of spring details and springs, with the exception of the crown; measuring tapes.

    Standards

    Name Code Standards
    Sheets and strips В23 GOST 103-2006
    Bars and shapes В22 GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
    Bars and shapes В32 GOST 1435-99, GOST 5210-95, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-1-505-73, TU 14-11-245-88, TU 14-1-1271-75
    Tape В34 GOST 2283-79, GOST 10234-77, GOST 21996-76, GOST 21997-76, TU 3-939-81, TU 14-1-2993-80, TU 14-1-3656-83, TU 14-175-80-89, TU 14-175-81-89, TU 14-4-99-73
    Sheets and strips В33 GOST 4405-75, TU 14-19-81-90, TU 14-131-971-2001
    Steel wire medium and high carbon В72 GOST 5468-88, GOST 9389-75
    Classification, nomenclature and General rules В20 OST 1 90005-91
    Blanks. Of the workpiece. Slabs В31 TU 14-1-3300-81
    Tape В24 TU 14-4-104-72

    Chemical composition

    Standard C S P Mn Cr Si Ni Fe Cu
    GOST 1435-99 0.75-0.84 ≤0.018 ≤0.025 0.17-0.28 ≤0.2 0.17-0.33 ≤0.25 Rest ≤0.25
    Fe is the basis.
    According to GOST 1435-99, the mass fraction of chromium, nickel and copper is indicated for 1 group of metal products. The mass fraction of sulfur in steel obtained by the electroslag remelting method should not exceed 0.013%. In the metal products of the 2nd group, the mass fraction of Cr ≤ 0.12%, Ni ≤ 0.12%, Cu ≤0.20% and their total mass fraction ≤ 0.40%. In the metal products of the third group, the mass fraction of Cr ≤ 0.20-0.40%, Ni ≤ 0.25%, Cu ≤0.25%. In metal products of the 1 st and 3 rd groups, made of steel obtained by scrap-process, the mass fractions of nickel, copper and chromium are increased by 0.05% of each element as compared to those in the table. In a metal designed for the manufacture of cold-rolled strip, an increase in the mass fraction of nickel, copper and chromium is not allowed.
    According to TU 14-1-505-73 in the steel grade U8A, intended for the manufacture of wire for the metal cord, the carbon content should be 0.74-0.80%. By agreement of the parties for special purpose hardware, steel must be supplied with reduced content limits of elements without treatment with synthetic slag and purging with argon.
    For the tape according to TU 14-1-2993-80 produced in accordance with GOST 2283, the deviation in chromium content is allowed up to +0,020%.

    Mechanical properties

    Section, mm sT|s0,2, MPa σU, MPa d5, % d4 d y, % HB, MPa HRC HV, MPa
    Tape flatted average strength of 0.1-4.0 mm according to GOST 10234-77 in the state of delivery (indicated delivery)
    - - 740-1270 - - - - - - -
    - - ≤780 - - ≥8 - - - -
    Tape cold-rolled heat-treated (0,05-1,30 mm) for spring parts and springs according to GOST 21996-76 and flattened strip (0,15-2,00 mm) according to GOST 21997-76 (listed group strength tape)
    - - 1270-1570 - - - - - - 375-485
    - - 1580-1860 - - - - - - 486-600
    - - ≥1860 - - - - - - ≥600
    Cold-rolled steel strip sagatovna (specified strength class)
    0.1-4 - 750-900 - - - - - - -
    Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm)
    - ≥1230 ≥1420 ≥10 - - ≥37 - - -
    Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91
    - - - - - - - - 44-48 -
    Cold-rolled steel strip sagatovna (specified strength class)
    0.1-4 - 900-1050 - - - - - - -
    Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm)
    - ≥1270 ≥1450 ≥11 - - ≥36 - - -
    Cold-rolled steel strip sagatovna (specified strength class)
    0.1-4 - 1050-1200 - - - - - - -
    Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm)
    - ≥1300 ≥1470 ≥12 - - ≥35 - - -
    Cold-rolled steel strip of 0.1-4.0 mm according to GOST 2283-79 on delivery
    0.1-4 - 740-1180 - - - - - - -
    A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C
    - - ≥105 ≥58 - - ≥91 - - -
    Cold-rolled steel strip of 0.1-4.0 mm according to GOST 2283-79 on delivery
    0.1-1.5 - ≤640 - ≥15 - - - - -
    A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C
    - - ≥91 ≥58 - - ≥100 - - -
    Cold-rolled steel strip of 0.1-4.0 mm according to GOST 2283-79 on delivery
    1.5-4 - ≤740 - ≥10 - - - - -
    A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C
    - - ≥55 ≥62 - - ≥100 - - -
    Cold-rolled steel strip of 0.1-4.0 mm according to GOST 2283-79 on delivery
    1.5-4 - ≤640 - ≥10 - - - - -
    A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C
    - - ≥33 ≥62 - - ≥100 - - -
    - - ≥21 ≥80 - - ≥100 - - -
    - - ≥15 ≥69 - - ≥100 - - -
    Annealing or normalizing
    - - ≤710 ≥17 - - ≥24 ≤195 - -
    - - ≤640 ≥15 - - ≥15 ≤205 - -
    - - ≤580 ≥17 - - ≥16 ≤205 - -
    - - ≤540 ≥19 - - ≥23 ≤190 - -
    - - ≤500 ≥23 - - ≥29 ≤170 - -
    - - ≤370 ≥28 - - ≥39 ≤150 - -
    - - ≤255 ≥33 - - ≥50 ≤120 - -

    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
    d4 Elongation after rupture
    d Elongation after rupture
    y The relative narrowing
    HB Brinell hardness number
    HRC Rockwell hardness (indenter diamond spheroconical)
    HV The Vickers hardness

    Physical characteristics

    Temperature Е, HPa G, HPa r, kg/m3 l, W/(m · °C) R, Mr. · m a, 10-6 1/°C С, J/(kg · °C)
    0 209 81 7839 - - - -
    100 205 80 7817 49 230 114 477
    200 199 77 7786 46 305 122 511
    300 192 74 7752 42 395 13 528
    400 185 71 7714 38 491 137 548
    500 175 67 7676 35 625 143 565
    600 166 62 7638 33 769 148 594
    700 - - 7600 30 931 152 624
    800 - - 7852 24 1129 145 724
    900 - - - 25 1165 - -
    1000 - - - - - 152 724
    1200 - - - - - 157 703

    A description of the physical symbols

    Name Description
    Е The normal elasticity modulus
    r Density
    l Coefficient of thermal conductivity
    R UD. the resistivity
    a The coefficient of linear expansion
    С Specific heat

    Technological properties

    Name The value
    Weldability Does not apply to welded structures. Method of welding - CCC.
    Склонность к отпускной хрупкости tend not
    The temperature of forging Start - 1180 °C, the end - of 800 °C. the cooling of the workpiece cross-section up to 100 mm in the air, 101-300 mm in the pit.
    Flock-sensitive sensitivity not sensitive.
    Machinability When NV 187-227 Kn TV.SPL.=1,2 Kn b.St.=1,1.
    Microstructure The microstructure of the untreated strips with thickness up to 2.2 mm on the other 14-1-2993-80 must meet: lamellar pearlite is not more than 6 points; tsementita mesh - no more than 3 points.
    Particularities of production of goods Rod on the other 14-1-505-73 comes Makiivka metallurgical plant.
    Sanding behaviour Good.