共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
采用3种喷丸强度(0.326,0.401,0.438 mm)对CF53钢进行表面喷丸强化,并在油润滑条件下进行销-盘式摩擦磨损试验,对比研究了喷丸前后试样的表面形貌、显微组织、显微硬度和耐磨性能.结果表明:喷丸强化后试样表面呈现酒窝状凹坑形貌,表面粗糙度、显微硬度和硬化影响区深度随喷丸强度的增加而增大;3种强度喷丸强化均提高了试样的耐磨性能,喷丸后的摩擦因数和体积磨损率均小于未喷丸试样的,喷丸强度为0.326 mm时试样的耐磨性能最佳;未喷丸试样的磨损机理为黏着磨损和材料剪切剥落,喷丸强度为0.326,0.401 mm时的磨损机理为剥层和磨粒磨损,喷丸强度为0.438 mm时则转变为疲劳磨损. 相似文献
3.
由于孔隙的存在,粉末冶金材料的性能较差,尤其是疲劳性能,而喷丸后续处理工艺可显著降低材料表面的孔隙率,对疲劳性能起到明显的强化效果。因此,采用超声弯曲疲劳试验方法研究喷丸后续处理工艺对Fe-2Cu-2Ni-1Mo-1C粉末冶金烧结材料的疲劳性能的影响。结果显示,喷丸处理可以明显提高Fe-2Cu-2Ni-1Mo-1C烧结钢的疲劳性能,在106、107、108循环周次条件下,喷丸前试样的条件疲劳极限分别为424 MPa、311 MPa和229 MPa,喷丸后的分别为513 MPa、421 MPa和346 MPa,依次提高了21.0%、35.2%和51.0%。断口分析发现,喷丸处理对Fe-2Cu-2Ni-1Mo-1C材料的疲劳断口的影响主要在裂纹萌生阶段,未经过喷丸处理的试样裂纹源集中在应力最大的试样喷丸表面棱角处,喷丸强化后的试样疲劳裂纹在喷丸表面的亚表面萌生,裂纹源有向试样亚表面移动的趋势。 相似文献
4.
高强度喷丸对300M钢抗疲劳性能的影响 总被引:1,自引:0,他引:1
采用喷丸强度分别为0.424mm和0.576mm的两种工艺对300M钢进行高强度喷丸强化,从表面完整性、残余应力场、显微硬度及抗疲劳性能等方面研究了高强度喷丸对300M钢的强化效果。结果表明:喷丸强化处理后,300M钢试样喷丸面均被弹坑完全覆盖,表面粗糙度显著提高;喷丸后试样表层形成较高的残余压应力场,表面显微硬度得到提高;喷丸后试样疲劳寿命比喷丸强化前的有小幅提高,较高的表面粗糙度造成的应力集中以及微裂纹的产生是其疲劳寿命没有明显提高的主要原因。 相似文献
5.
6.
前混合水射流喷丸强化表面力学特性及疲劳寿命试验 总被引:5,自引:0,他引:5
为获得前混合水射流喷丸强化增益效果,研究前混合水射流喷丸对2A 11铝合金和45钢的表面显微硬度、表面残余压应力和疲劳寿命的影响.采用显微硬度计和X射线应力分析仪分别测定喷丸表面显微硬度和表面残余应力,利用扫描电镜观察疲劳断口形貌,获得喷丸表面显微硬度和表面残余压应力随喷丸压力、扫描速度及靶距的变化规律,指出射流喷丸可以大幅度地提高2A11铝合金和45钢的疲劳寿命,当2A11铝合金和45钢的应力振幅分别为155.7 MPa和282MPa时,喷丸试样疲劳寿命比未喷丸试样疲劳寿命分别提高25.31倍和18.56倍,且未喷丸试样疲劳裂纹萌生于试样表面,喷丸试样疲劳裂纹有的萌生于试样表面,有的萌生于试样内部,当疲劳源在试样内部时,裂纹在夹杂物处萌生.因此,前混合水射流喷丸是一种提高金属零构件疲劳寿命的有效方法. 相似文献
7.
8.
喷丸强化对新型7055-T7751铝合金疲劳性能的影响 总被引:4,自引:0,他引:4
对7055-T7751新型铝合金表面进行了陶瓷丸喷丸强化处理,采用X射线衍射仪、表面轮廓仪、扫描电子显微镜、显微硬度计等研究了喷丸强度、喷丸覆盖率等工艺参数对铝合金表面残余应力场、表面粗糙度、表面损伤及表面加工硬化和疲劳性能的影响。结果表明:优化工艺参数下的喷丸强化能够显著提高该铝合金的疲劳性能,并不是喷丸强度或喷丸覆盖率越高强化效果越好,而是存在合理的喷丸强化参数范围,在优化条件下铝合金可以获得良好的综合表面完整性,疲劳断裂抗力最高;确定的优喷丸参数为喷丸强度0.15mm,覆盖率100%,以此参数强化处理的7055-T7751铝合金的疲劳寿命是基材的2.7倍。 相似文献
9.
10.
11.
S.M. H-GangarajY. Alvandi-Tabrizi G.H. Farrahi G.H. MajzoobiH. Ghadbeigi 《Tribology International》2011,44(11):1583-1588
Shot peening is widely used to improve the fretting fatigue strength of critical surfaces. Fretting fatigue occurs in contacting parts that are subjected to fluctuating loads and sliding movements at the same time. This paper presents a sequential finite element simulation to investigate the shot peening effects on normal stress, shear stress, bulk stress and slip amplitude, which are considered to be the controlling parameters of fretting damage. The results demonstrated that among the modifications related to shot peening, compressive residual stress has a dominant effect on the fretting parameters. 相似文献
12.
Peening, using cavitation impacts induced by bubble collapse, represents a novel surface enhancement technique for machine parts without involving conventional shot peening blasting. This is known as cavitation shotless peening, CSP. The improvement in the fatigue strength of a spur gear after CSP has been demonstrated. The fatigue strength of a gear treated with CSP was improved by about 60%, compared with that of a non-peened gear. 相似文献
13.
14.
15.
强力喷丸对提高碳氮共渗齿轮接触疲劳强度的研究 总被引:1,自引:0,他引:1
通过对碳氮共渗齿轮试片进行了多次强力喷丸试验.研究了不同喷丸参数下的强力喷丸的效果及喷丸后的低温回火处理对提高齿轮试片表面接触疲劳强度的影响。为强力喷丸工艺更好地应用于工业生产提供了一些参考。 相似文献
16.
Baskaran Bhuvaraghan Sivakumar M. Srinivasan 《International Journal of Mechanical Sciences》2011,53(6):417-424
Almen intensity is used in the shot peening industry as a standard measure of the residual stress during shot peening and it is employed to ensure the quality of the peening of identical parts. However, relating the intensity to the residual stresses in the strip needs to be established with confidence by realistic simulations. An improved FEM-based approach that simulates the actual process of Almen strip peening is presented in this paper. This approach has some unique features such as employing randomly located shots impacting on a slice of Almen strip and the inclusion of strain-rate dependent target material properties and the lateral deflection of the strip for improved accuracy. The intensity, the corresponding residual stresses and roughness match well with available experimental results. Further, it is shown in this study that the Almen intensity can be correlated well with the residual compressive stresses of the target material using a parameter that depends on the relative dynamic yield strength of the target material. 相似文献
17.
斯太尔连杆喷丸强化工艺攻关试验 总被引:2,自引:0,他引:2
在我国引进了斯太尔发动机制造技术,其重要运动部件连杆由于承受交变载荷,必须进行表面喷丸强化处理,该文着重介绍了喷丸强化的原理,喷丸强度的计算和控制程序,以及根据国内条件研制的喷丸介质与喷丸设备。 相似文献
18.
Numerical Calculation and Experimental Research on Residual Stresses in Precipitation-hardening Layer of NAK80 Steel for Shot Peening 总被引:1,自引:1,他引:0
MIAO Hong ZUO Dunwen WANG Min ZHANG Ruihong WANG Hongfeng Jiangsu Key Laboratory of Precision Micro-Manufacturing Technology Nanjing University of Aeronautics Astronautics Nanjing China College of Mechanical Engineering Yangzhou University Yangzhou China 《机械工程学报(英文版)》2011,(3):439-445
Shot peening can improve fatigue strength of materials by creating compressive residual stress field in their surface layers,and offers a protection against crack initiation and propagation,corrosion,etc.And fatigue fracture and stress corrosion cracking of NAK80 steel parts are improved effectively.Currently there lacks in-depth research in which the beneficial effect of the residual stress may be offset by the surface damage associated with shot peening,especially in terms of the research on the effective control of shot peening intensity.In order to obtain the surface residual stress field of NAK80 steel after shot peening,the samples are shot peened by pneumatic shot peening machine with different rules.The residual stress in the precipitation-hardening layer of NAK80 steel is measured before and after a shot peening treatment by X-ray diffraction method.In order to obtain true residual stress field,integral compensation method is used to correct results.By setting up analytical model of the residual stress in the process of shot peening,the surface residual stress is calculated after shot peening,and mentioning the reason of errors occurred between calculated and experimental residual stresses,which is mainly caused by the measurement error of the shoot arc height.At the same time,micro hardness,microstructure and roughness in the precipitation-hardening layer of NAK80 steel before and after shot peening were measured and surveyed in order to obtain the relation between shot peening strength and surface quality in the precipitation-hardening layer.The results show that the surface quality of NAK80 steel is significantly improved by shot peening process.The over peening effect is produced when the shot peening intensity is too high,it is disadvantageous to improve sample’s surface integrity,and leading to reduce the fatigue life.When arc high value of optimal shot peening is 0.40 mm,the surface quality is the best,and the depth of residual stress in the precipitation-hardening layer reaches to about 450 μm.Numerical calculation is very useful to define the process parameters when a specific residual stress profile is intended,either to quantify the benefits on a specific property like fatigue life or to help on modeling a forming process like shot peen forming.In particular,the proposed parameter optimization in the progress of shot peening and effective control of the surface texture provide new rules for the quantitative evaluations of shot peening surface modification of NAK80 steel. 相似文献
19.
作为机械表面强化技术之一,喷丸强化使工件表层发生形变硬化,引入较高的残余压应力,减少了疲劳应力作用下微裂纹的萌生并抑制其扩展,从而显著提高零件的抗疲劳断裂和抗应力腐蚀开裂的能力。基于喷丸残余应力解析计算模型,从余弦函数模型、接触应力模型和球腔膨胀模型三个方面介绍喷丸强化残余应力的产生,进而对喷丸残余应力的仿真预测及影响规律进行论述。为了提高试件疲劳强度而引入的残余压应力会带来影响形位精度的变形,基于此阐述了喷丸残余应力对疲劳性能的影响及其在疲劳过程中的演化,同时论述了喷丸残余应力变形预测及控制的研究现状,最后对喷丸残余应力未来的研究内容与发展方向进行展望。 相似文献