共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
GCr15钢网状碳化物细化工艺 总被引:2,自引:1,他引:1
GCr15轴承钢锻后冷却速度不当会出现粗大的网状碳化物.用正火处理消除粗大网状碳化物的方法,所需费用高。用轴承套圈冷却装置.使锻后的套四经过鼓风强冷、喷雾水冷,在低速运动中逐件冷却,可按生产拍节调整运动速度,保证消除粗大网状碳化物。 相似文献
3.
4.
对某轴承套圈裂纹产生原因进行了分析,通过化学和金相检测,对套圈的材料质量和热处理质量进行全面分析,对裂纹和脱碳的产生进行整个工艺过程讨论和论证,并经摸拟试验,证明套圈裂纹是锻造湿裂。 相似文献
5.
提出了一种圆锥滚子轴承套圈锻压生产的新工艺。在使用高速镦锻机进行轴承套圈锻造生产时,L68149/11等型号轴承由于内圈锻件最大外径尺寸大于外圈最小内孔尺寸,致使内外圈通常不能套锻生产,通过应用冷挤压辅助成形工艺,可以有效解决该类产品在高速镦锻机上的套锻生产难题,降低生产成本。 相似文献
6.
对某轴承套圈裂纹产生原因进行了分析,通过化学和金相检测,对套圈的材料质量和热处理质量进行全面分析,对裂纹和脱碳的产生进行整个工艺过程讨论和论证,并经摸拟试验,证明套圈裂纹是锻造湿裂。 相似文献
7.
8.
9.
采用金相显微组织检验、扫描断口分析等方法,对轴承套圈产生断裂的原因进行了分析,认为断裂是由最终热处理以后的几道工序中在断裂轴承套圈背面后沿与顶部交界处产生的浅裂纹引起的。此部位存在的拉应力以及淬火时存在的淬硬层深度的尖角效应对浅裂纹的形成和扩展起促进作用。 相似文献
10.
11.
12.
13.
针对用Crl2MoV制造的轴承滚柱冷镦凹模寿命短的问题,分析了其失效的形式及原因。提出了提高凹模寿命的措施:锻造。采用预先热处理退火、调质、去应力退火工艺,改进淬火、回火工艺,增加表面处理工艺等。 相似文献
14.
15.
Radial expansion of thick-walled discs can produce a hoop tensile plastic instability after which failure occurs by an oblique shear fracture in the neck. However, in discs manufactured from metallurgically dirty meals (containing many inclusions) cracks can be initiated before the instability strain and failure occurs along an essentially radial path without necking. In this second case, crack nucleation sites are within the outer half or third of the annulus. While criteria of fracture based on maximum tensile or shear stresses fail to predict such locations of first cracking within the walls they are well predicted by McClintock-type ductile fracture integrated damage functions. Damage concerns the growth and coalescence of voids and is a function of strain and hydrostatic stress. The functions also show qualitatively why the sites of cracks initiated after necking (in materials with cleaner microstructures) are located much closer to the bore. In rotating discs which fracture, cracks are also initiated sometimes within the annulus, which again is not anticipated by failure criteria based on stress alone, but McClintock damage functions well predict the experimentally observed behaviour. 相似文献
16.
17.
18.
《Wear》2002,252(9-10):811-823
In rolling contact fatigue, we have discovered that a flaking failure accompanied by cracks extending bi-directionally relative to the load-movement occurs on a defect-free surface due to the influence of indentations on a mating surface. We have also demonstrated, using stress analysis, the initiation of incipient cracks in the subsurface region resulting from indentations on the mating surface. In the present study, we focus on the stage of crack extension in the direction opposite to the load-movement. Firstly, mode II fatigue crack growth properties are investigated by conducting mode II fatigue testing, which has been previously presented. Subsequently, stress intensity factors at a subsurface crack are calculated by using a finite element method for the case of an indentation on the mating surface moving through the contact area. In this calculation, the configuration of the modeled crack is very similar to cracks actually observed. Based on the results of both the stress analysis and the cracking seen in actual tests, the mechanism for the development of opposite-directional cracking is proposed to be a mode II extension of an incipient subsurface crack. 相似文献
19.