《机械制造基础》复习试题答?- 百度文库 ر

Ӧйˮƽ ṹ

10νѹܣӰѹܵЩ 𣺽ѹε׳̶ȳΪĶѹܡ

Ҫأѧɷ ֯ṹ ¶ ٶ Ӧ״̬ 11ȴȱЩ 𣺹

̼ κͿ Ӧ ӲȲ 㡢ʴ⣺

1ⶨijֵָѧʱ֪԰ֱ10mm,೤ֱ屶 Fb=33.81KNFs=20.68KNϺı೤65mm

˸ֵĦsbֵǶ٣

⣺s=Fs/Ao=20680/3.1452=263.44Mpa

b=Fb/Ao=33810/3.1452=430.70Mpa ģ6550=30

𣺴˸ֵĦs=263.44Mpa b=430.70Mpa =30

2.һԭʼֱΪ10mmԭʼ೤Ϊ50mmغɴﵽ18.84kNʱغɼ36.11kNʱȻϣϺ೤Ϊ73mmѴֱΪ6.7mmĦsb5?

:㹫ʽ

s=Fs/So=18840/3.14*102/4=240(N/mm2) b =Fb/So=36110/3.14*102/4=460(N/mm2) 5=(L1-L0)/L0100%=(73-50)/50=46%

?=(S0-S1)/S0100%={(3.14*102/4)- (3.14*6.72/4)}/3.14*102/4

=(100-44.89)/100=55.11%

:Ħs=240(N/mm2)b =460(N/mm2)5=46%?=55.11%

3򻯵̼Ͻ״̬ͼ40Һ̬õƽ֯

4̼Ϊ0.4%1.2%̼ϽҺ̬ʱ֯仯̡

𣺶̼Ϊ0.4̼ϽҺ̬ACʱʼᾧ壨A¶½壨A࣬Һ٣¶ȽAEʱҺʧҺȫᾧΪ壨A¶ȽGSʱӰ壨FPSKʱʣ巢ת䣬壨P¶ȽPSKʱ֯ޱ仯

֯Ϊ壨F+P

̼Ϊ1.2̼ϽҺ̬ACʱʼᾧ壨A¶½壨A࣬Һ٣¶ȽAEʱҺʧҺȫᾧΪ壨A¶ȽESʱӰ̼壨Fe3CIIPSKʱʣ巢ת䣬壨P¶ȽPSKʱ֯ޱ仯֯Ϊ壨Fe3CII +P

5.Ŀʲôǹֺ͹ֵĴ¶Ӧѡ

ĿҪʹּõ(ͱ)֯߸ֵӲȺǿȣʵĻػϣõطӸֲĵDZ

ǹִ¶ΪAc330桫50棬Ϊڴ¶ȷΧڣɻȫϸСİ徧õϸС塣¶ȹߣ徧ִʹִܱ仵¶ȹͣ֯δ壬ʹִӲȲ㡣

ֺ͹ִ¶ΪAc130桫50棬ʱ֯Ϊ̼ϸС״̼壬ִܱ֤õߵӲȺĥԡ¶ȳAccm̼ʧ徧ֻõִ״壬࣬ӲȺĥԽͣ¶ȹͣܵõֵ֯ӲȴﲻҪ

6.ֻػ𷽷õܼ֯Ӧ

𣺳ֻػ𷽷õܼ֯Ӧü±

ػ »ػ ֯ ػ ӲȺĥԣԺԵ Ӧ оߡߡе

»ػ »ػ ػ ػ ӲУԸ ӲУԺԺ ᡢˡ֡˨ 7˵ƺ?ֺͷŸʾʲô? 20Cr 9CrSi 60Si2Mn GCr15 1Cr13 Cr12

20CrǺϽ̼֣WC=0.2%WCr=1%

9CrSiǺϽ𹤾߸֣WC=0.9%WCr=1%WSi=1% 60Si2MnǺϽ𵯻ɸ֣WC=0.6%WSi=2%WMn=1% GCr15ǹи֣WC=0.95~1.15%WCr=1.5% 1Cr13Dz֣WC=0.1%WCr=13% Cr12ǺϽ𹤾߸֣WC1.0%WCr=12%.

8.бȽϺϽ̼֡Ͻʸ֡Ͻ𵯻ɸ֡иֵĵƺšȴҪ;

𣺺Ͻ̼֡Ͻʸ֡Ͻ𵯻ɸ֡и̼ƺšȴҪܼ;±

̼ WC=0.2% WC=0.4% Ͻ𵯻ɸ WC=0.7% и WC=1.0% ƺ ȴ Ҫ ; 20CrMnTi 40Cr +»رӲĥ ֡Сᡢ졢 Ͻ̼ +»ۺܺ +»صԸ +»ػ ӲĥƣǿСߡģ ȸ ֡ˡ Ͻʸ 60Si2Mn GCr15 9.ӰʯīЩ?