自紧载压低温处理厚壁圆筒的强度及疲劳寿命研究

将6支中小尺寸模拟管进行自紧载压低温处理,对3支精加工前后的小尺寸模拟管和3支精加工后的中尺寸模拟管分别进行弹性强度测试,将具有内表面预制裂纹的6支中小尺寸模拟管进行液压循环疲劳寿命试验。结果表明:当壁厚比为1.768、自紧度为0.8、模拟管材料屈服强度Rr0.1≥1 200 MPa时,精加工后模拟管实测强度为700~721 MPa(自紧压力为756~792 MPa);在循环压力600MPa下,6支模拟管都以穿透型形式泄漏破坏,最终疲劳寿命为2504~3499次。

Strength and fatigue life of autofrettaged thick-wall cylinder after low temperature heat soak under pressure loading

After being autofrettaged and treated at low temperature under pressure loading of six small and middle size simulationtubes,the elastic strength of three small size simulation tubes before and after machining and other three middle size simulationtubes after machining was tested. Hydraulic pressure cycle fatigue life test was made for all six simulation tubes with inner boresurface cracks prefabricated. The test result indicates that,when autofrettage pressure is from 756 to 792 MPa,the wallthickness ratio W=1.768,the level of overstrain Os=0.8 and the yield strength of the material Rr0.1≥1 200 MPa,the real elasticstrength of the simulation tube after machining can be from 700 to 721 MPa. Under the cycle pressure of 600 MPa,all of the sixsimulation tubes are destroyed with Leak-Before-Break mode,their fatigue life is from 2 504 to 3 499 cycles.