STP64

    Residual Stress in Caliber 0.30 Cartridge Cases

    Published: Jan 1945


      Format Pages Price  
    PDF (368K) 15 $25   ADD TO CART
    Complete Source PDF (64K) 15 $126   ADD TO CART


    Abstract

    An investigation has been made of residual stress in the head and body of caliber 0.30 cartridge cases. The head was divided into four ring-like sections which were cut off by a jeweler's saw. Spring-out was measured after a radial cut had relieved the circumferential bending moment. The residual stress corresponding to the observed spring-out was calculated by formulas in which the computed stress was a function of wall thickness. All rings sprang open, indicating compressive stress on the inner wall and tensile stress on the outer wall. The production stress-relief anneal of 475 F. for 45 min. reduced the stress to almost half. The priming and crimping operation, however, again raised the stress, especially in the flange section. The effect of stress-relief heat treatments on residual stresses in the body of caliber 0.30 cartridge cases was investigated by the split-ring method. Although this method did not reveal any large stresses in the body, the neck before mouth anneal was found to contain a computed stress of 30,000 psi. at the surface. This value was reduced to 15,000 psi. in 120, 30, and 15 min. at 400, 475, and 500 F., respectively.


    Author Information:

    Rosenthal, H.
    Metallurgist and Chemist, Ordnance Laboratory, Frankford Arsenal, Philadelphia, Pa.

    Mazia, J.
    Metallurgist and Chemist, Ordnance Laboratory, Frankford Arsenal, Philadelphia, Pa.


    Paper ID: STP42569S

    Committee/Subcommittee: B05.06

    DOI: 10.1520/STP42569S


    CrossRef ASTM International is a member of CrossRef.