钢铁材料的许用应力

表1 普通碳钢及优质碳钢构件基本许用应力 /MPa材料类型材料标号截面尺寸/mm热处理材料性能拉 压弯 曲扭 转剪 切抗拉强度 b屈服强度 s/MPalllnnn普通碳钢Q215100热扎b335410s185215145125901751401059590601009060Q235b375460s205235160140100190160120105956511010070Q275b490610s2352751751501102101701301151057012011080优质碳钢20100正火b410s245175145105210165125115105701201057525b450s275195160115230175135125115751351208035b530s3152101801252502001501351208014512085调质b550750s320370210185130250205155135125851451208545正火b600s3552302001452702201701501359016014095调质b630800s3704302502151503002351801601501001751501005025正火b630s375250215150300235180160150100175150100100调质b700s400265235165310260195170155105180160110表2 碳钢铸件基本许用应力 /MPa材料标号截面尺寸/mm热处理材料性能拉 压弯 曲扭 转剪 切抗拉强度 b屈服强度 s/MPalllnnnZG200400100正火及回火b400s20013512090160135105908060958560ZG230450b450s23015514010018515512010085651109065ZG270500b500s2701751601152101751351151007512010575ZG310570b570s3101901701252301901451251058013011080ZG340640b640s3402001801302402051551301158714012087表3 灰铸铁基本许用应力 /MPa材料标号壁 厚/mm抗压强度/MPa抗拉强度/MPa中 心 抗 压弯 曲扭 剪压拉拉 压lllllHT-1502.51050070017514080502820503023452418102014514080412417412519372015203013014080372115372217331813305012014080341914342115311712HT-2002.510600800220170100633625633828573123102019517010056322256332550272020301701701004928194929224424173050160170100462618462721412216HT-2504.0108001000270230130774431774635693728102024023013069392769413162332520302202301306336256338285731233050200230130573223573426512821HT-30010201000120029028516083473383503775403020302502851607141297143326435263050230285160663726663930593224HT-35010201100130034031518097553997584487473520302903151808347338350377540303050260315180744230744433673627 附表 钢铁的许用应力（kgf/cm2）载 荷软 钢中 硬 钢铸 钢钢 铁拉 伸90015006001000300 50012001800800 1200400 6006001200400600200400300200100压 缩9001500600100012001800800 120090015006001000900600弯 曲90015006001000300 50012001800800 1200400 6007501200500 800250 400剪 切7201200480 800240 4009601440640 960320 480480960320640160320300200100扭 转6001200400 800200 4009001440640 960320 480480960320640160320（注）载荷指 ：静载荷：重复载荷：交变载荷表4 许用弯曲应力材 料极限强度kgf/cm2许用应力 kgf/cm2稳定载荷冲击或脉动载荷反复交变载荷碳 素 钢400050006000700013001700200023007007509501100400450550650合 金 钢8000100002700330013001600750900铸 钢4000500010001200500700300400表5 轴的常用材料及许用弯曲应力30钢 号处 理毛坯直径(mm)机 械 性 能硬 度HB许用弯曲应力wkgf/cm2bkgf/mm2skgf/mm2-1kgf/mm235正 火正 火正 火正火+回火调 质251001003003005005007501001003005452504846565432272624233028262524232226.525.51871431871431871371871311871632011442011100105010009609201100108045正 火正 火正 火正火+回火调 质251001003003005005007002006160585654653630292827362827.52726253024117020716320715620714920718722911501150113010801050125035SiMn42SiMn调 质251001003003004004005009080757065755245403846403532.531.52292862172692172551972551600140014001350130040MB调 质2520010075805050362402901750145038SiMo调 质100100300300500500800757270606055504038363530228286217269197241186241150014501400125040Cr调 质25100100300300500500800100757065608052504035503735312924128624128622926021726017501500148013001200注：表中-1适用于48，如果光洁度提高或降低，-1应相应提高或降低515%。表6 轴类零件允许变形的参考数值变形名 称变 形 允 许 值挠度一般用途的轴需要提高刚度的转轴安装齿轮的轴安装蜗轮的轴=(0.00030.0005)=0.0002=(0.010.05)mn=(0.010.05)mt转角滑动轴承向心球轴承向心球面轴承圆柱滚子轴承圆锥滚子轴承安装齿轮的轴承=0.001rad=0.005rad=0.005rad=0.0025rad=0.0016rad=0.001rad注：轴承之间的长度(mm)；mn齿轮法面模数(mm)；Mt蜗轮的端面模数(mm)。表7 轴弯曲的允许变形量30名 称挠 度 允 许 值fcm一般用途的轴刚度要求高的轴安装齿轮的轴安装蜗轮的轴0.00030.0005(跨度)0.00020.010.030.020.05名 称倾 角 允 许 值rad装齿轮或滑动轴承处向心球轴承处向心球面轴承处短圆柱滚子轴承处圆锥滚子轴承处=0.001=0.005=0.005=0.0025=0.0016