autofrettagen.
/ˈɔːtə(ʊ)ˌfrɛtɪdʒ/, /ˌɔːtə(ʊ)frɛˈtɑːʒ/, U.S. /ˈɔdəˌfrɛdɪdʒ/, /ˈɔdoʊˌfrɛdɪdʒ/, /ˈɑdəˌfrɛdɪdʒ/, /ˈɑdoʊˌfrɛdɪdʒ/, /ˌɔdoʊˌfrɛˈtɑʒ/, /ˌɑdoʊˌfrɛˈtɑʒ/ The process of strengthening a tube, esp. a gun barrel, by subjecting it to internal pressure high enough to enlarge the bore and push the inner metal (but not the outer metal) beyond its elastic limit.
ΘΚΠ
society > occupation and work > industry > working with specific materials > working with metal > [noun] > other metalworking processes
limation1617
matting1688
sheeting1776
blooming1812
steeling1816
ungraining1839
tarnishing1858
ironing1868
shimming1872
beating1875
siliconizing1880
shearing1881
inoxidizing1883
rustproofing1892
picking1895
rifting1903
Bayer process1910
autofrettage1919
prefinishing1935
panel beating1953
splatting1976
1919 Rep. Chief of Bureau of Ordnance to Secretary of Navy (U.S. Navy Dept. Bureau of Ordnance) 37 Guns..Vickers-Terni 37-millimeter aircraft gun; 25.4 millimeter Italian automatic gun; 8-inch howitzer; 4-inch auto-frettage gun (radial expansion).
1920 Proc. U.S. Naval Inst. Dec. 1969 The pressure of autofrettage is limited to such a pressure that..there shall not be developed any new permanent deformations in the interior layer.
1950 Engineering 28 Apr. 479/3 Autofrettage is the art of inducing elasticity in a tube at pressures which otherwise cause overstrain.
1989 Engin. Fracture Mech. 33 928 Good surface finish and a moderate autofrettage treatment in alloy steels are known to be beneficial to both fatigue life and fatigue limit.
2004 B. Crossland in J. B. Wintle Pressure Syst. Casebook ix. 137 They were not happy at the additional cost of auto-frettage, low-temperature, heat treatment and re-machining the bore.
Derivatives
ˈautoˌfrettaged adj. that has been subjected to autofrettage.
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1925 Trans. Amer. Soc. Steel Treating 8 472 The use of alloys in auto-frettaged steel is promising.
1971 Adv. Technol. for Naval Gun Tubes (National Materials Advisory Board) iv. 50 The autofrettaged gun also shows a significantly longer life before initiation of cracks and a much lower rate of crack extension.
2004 M. T. Hutchings et al. Introd. Charactrization Residual Stress Neutron Diffraction i. 7 Common applications..include measurement of stresses due to welding, plastically deformed structures such as autofrettaged tubes and cold expanded holes.
This entry has been updated (OED Third Edition, June 2011; most recently modified version published online December 2021).
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n.1919