Low Pressure Hydrogen Gas Effect on Extremely Low Fatigue Crack Growth from Small Blind Holes of SUS304 and SUS316L(<Special Issue>Solid Mechanics Indispensable for Automobile Engineering)

Abstract

In Qrder lo invcst ｛ gate the 1 ユydrogen gas efrect 〔 m the fatTgue limits of austen ［ tic st 自inless stee ］ SUS3 〔 ， 4 and SUS316Lwith small twin b 「 ind ho ' es ， meLal fat 雪 gue 吐 ests are carried Qut iTl a low pressure hydrog 巳 n gas， in f ir and inert gases ； argor 〕 oT niLrogen ， The fatigue limit〔♪ f S疋IS304 is de百ned as the crackpropagation hinit not し )】 コlyin airbut a ］ so lr 】hydrogeII and in nitr ' ： ｝ gen ， And the faし igue limit of SUS3 〔 14 ill hydrogen gas is slightlyhigher tha ロ in air ． The extrelllely low Fatiguo 〔 二 rack Gr 〔 ｝ wth Rates ( FCGR )ofn ( 几 only SUS304 and but also SI ． FS？ ，⊥ 6L inhyclrogen ffas is lower 亡 han し ha しin ar 墓 Qn gas in the region of FCGRIower thaniO − e m 、 ！ cycle ． This see 】lr1 t． O be duc し〔 ) plasticil ． y − illduced crack closure and sl1PP ( ，rts hjgher far ． igue lirnit itl hydrugen 、 A