鋼鐵材料的許用應(yīng)力

1、表1 普通碳鋼及優(yōu)質(zhì)碳鋼構(gòu)件基本許用應(yīng)力 /MPa材料類型材料標(biāo)號截面尺寸/mm熱處理材料性能拉 壓彎 曲扭 轉(zhuǎn)剪 切抗拉強(qiáng)度 b屈服強(qiáng)度 s/MPalllnnn普通碳鋼Q215100熱扎b335410s185215145125901751401059590601009060Q235b375460s205235160140100190160120105956511010070Q275b490610s2352751751501102101701301151057012011080優(yōu)質(zhì)碳鋼20100正火b410s245175145105210165125115105701201057525b450

2、s275195160115230175135125115751351208035b530s3152101801252502001501351208014512085調(diào)質(zhì)b550750s320370210185130250205155135125851451208545正火b600s3552302001452702201701501359016014095調(diào)質(zhì)b630800s3704302502151503002351801601501001751501005025正火b630s375250215150300235180160150100175150100100調(diào)質(zhì)b700s4002652351

3、65310260195170155105180160110表2 碳鋼鑄件基本許用應(yīng)力 /MPa材料標(biāo)號截面尺寸/mm熱處理材料性能拉 壓彎 曲扭 轉(zhuǎn)剪 切抗拉強(qiáng)度 b屈服強(qiáng)度 s/MPalllnnnZG200400100正火及回火b400s20013512090160135105908060958560ZG230450b450s23015514010018515512010085651109065ZG270500b500s2701751601152101751351151007512010575ZG310570b570s3101901701252301901451251058013011080

4、ZG340640b640s3402001801302402051551301158714012087表3 灰鑄鐵基本許用應(yīng)力 /MPa材料標(biāo)號壁 厚/mm抗壓強(qiáng)度/MPa抗拉強(qiáng)度/MPa中 心 抗 壓彎 曲扭 剪壓拉拉 壓lllllHT-1502.51050070017514080502820503023452418102014514080412417412519372015203013014080372115372217331813305012014080341914342115311712HT-2002.5106008002201701006336256338285731231020195

5、17010056322256332550272020301701701004928194929224424173050160170100462618462721412216HT-2504.0108001000270230130774431774635693728102024023013069392769413162332520302202301306336256338285731233050200230130573223573426512821HT-3001020100012002902851608347338350377540302030250285160714129714332643526

6、3050230285160663726663930593224HT-35010201100130034031518097553997584487473520302903151808347338350377540303050260315180744230744433673627 附表 鋼鐵的許用應(yīng)力（kgf/cm2）載 荷軟 鋼中 硬 鋼鑄 鋼鋼 鐵拉 伸90015006001000300 50012001800800 1200400 6006001200400600200400300200100壓 縮9001500600100012001800800 120090015006001000900

7、600彎 曲90015006001000300 50012001800800 1200400 6007501200500 800250 400剪 切7201200480 800240 4009601440640 960320 480480960320640160320300200100扭 轉(zhuǎn)6001200400 800200 4009001440640 960320 480480960320640160320（注）載荷指 ：靜載荷 ：重復(fù)載荷 ：交變載荷表4 許用彎曲應(yīng)力材 料極限強(qiáng)度kgf/cm2許用應(yīng)力 kgf/cm2穩(wěn)定載荷沖擊或脈動載荷反復(fù)交變載荷碳 素 鋼40005000600070

8、0013001700200023007007509501100400450550650合 金 鋼8000100002700330013001600750900鑄 鋼4000500010001200500700300400表5 軸的常用材料及許用彎曲應(yīng)力30鋼 號處 理毛坯直徑(mm)機(jī) 械 性 能硬 度HB許用彎曲應(yīng)力wkgf/cm2bkgf/mm2skgf/mm2-1kgf/mm235正 火正 火正 火正火+回火調(diào) 質(zhì)251001003003005005007501001003005452504846565432272624233028262524232226.525.51871431871

9、431871371871311871632011442011100105010009609201100108045正 火正 火正 火正火+回火調(diào) 質(zhì)251001003003005005007002006160585654653630292827362827.52726253024117020716320715620714920718722911501150113010801050125035SiMn42SiMn調(diào) 質(zhì)251001003003004004005009080757065755245403846403532.531.5229286217269217255197255160014001

10、4001350130040MB調(diào) 質(zhì)2520010075805050362402901750145038SiMo調(diào) 質(zhì)100100300300500500800757270606055504038363530228286217269197241186241150014501400125040Cr調(diào) 質(zhì)25100100300300500500800100757065608052504035503735312924128624128622926021726017501500148013001200注：表中-1適用于48，如果光潔度提高或降低，-1應(yīng)相應(yīng)提高或降低515%。表6 軸類零件允許變形的參考數(shù)值變形名 稱變 形 允 許 值撓度一般用途的軸需要提高剛度的轉(zhuǎn)軸安裝齒輪的軸安裝蝸輪的軸=(0.00030.0005)=0.0002=(0.010.05)mn=(0.010.05)mt轉(zhuǎn)角滑動軸承向心球軸承向心球面軸承圓柱滾子軸承圓錐滾子軸承安裝齒輪的軸承=0.001rad=0.005rad=0.005rad=0.0025rad=0.0016rad=0.001rad注：軸承之間的長度(mm)；mn齒輪法面模數(shù)(mm)；Mt蝸輪的端面模數(shù)(mm)。表7 軸彎曲