STP755: Mechanical Properties of Vacuum Carbon-Deoxidized Thick-Wall 2¼Cr-1Mo Steel Forging

    Kohno, M
    Senior Researcher and Manager, Takasago Plant, Kobe Steel, Ltd., Hyogo-ken,

    Makioka, M
    Assistant Manager, Takasago Plant, Kobe Steel, Ltd., Hyogo-ken,

    Kinoshita, S
    Assistant Manager, Takasago Plant, Kobe Steel, Ltd., Hyogo-ken,

    Suzuki, A
    Senior Researcher and Manager, Takasago Plant, Kobe Steel, Ltd., Hyogo-ken,

    Pages: 20    Published: Jan 1982


    Abstract

    The effect of postweld heat treatment on the susceptibility to temper embrittlement of 2¼Cr-1Mo steel forgings which have various silicon contents has been investigated. Then, to verify the validity of low-silicon 2¼Cr-1Mo steel for an actual forging, the mechanical properties and the susceptibility to temper embrittlement of a 296-mm (11.7-in.)-thick forged ring made from a 100-ton ingot with silicon content reduced to below 0.10 percent by the vacuum carbon deoxidation (VCD) process have been tested. The results are as follows: (1) the through-thickness mechanical properties of the forging meet the requirements of ASME SA-336, F22; (2) silicon content has no significant effect on the creep-rupture strength at least to 15 000 h at 550°C (1022°F) and 600°C (1112°F); and (3) the susceptibility to embrittlement is very low, as the shift in 50 percent fracture appearance transition temperature is 14°C (25°F) for step cooling and 22°C (40°F) for isothermal treatment at 475°C (887°F) for 5000 h.

    Keywords:

    2¼Cr-1Mo steel, mechanical property, temper embrittlement, creep strength, postweld heat treatment, silicon, vacuum carbon deoxidation process


    Paper ID: STP28417S

    Committee/Subcommittee: A01.06

    DOI: 10.1520/STP28417S


    CrossRef ASTM International is a member of CrossRef.