In order to study the influence of high-temperature

high-pressure and high-speed propellant gas on barrel stress when shooting

analysis on stress of barrel and the plastic deformation were conducted under the pressure of powder gases and thermal stress caused by continuous emission process. The finite element model of rapid-firing gun was established and the direct coupling method was employed.The conclusion was that the plastic deformation happened only inside the thin layer of base near chromium steel interface(about 0.467 mm thickness)

and with the accumulation of continuous emissions plastic deformation increased and became stable

the maximal equivalent residual stress was 470 MPa existing in the thin layer.Under the influences of residual stress

reverse yielding plastic deformation happened in the thin layer during the first shot after cooling

and the maximal equivalent residual stress reduced by about 50%;the residual stress could obviously weaken the thermal stress which made stable for barrel stress.