花键轴断裂原因分析

通过对断裂花键轴断口的宏微观形貌、材料化学成分、金相显微组织、硬度及形状尺寸进行了测试与分析,并应用理论计算和有限元模拟分析,确定了花键轴的断裂性质及断裂原因。结果表明：该花键轴的断裂性质为扭转疲劳断裂,花键轴发生扭转疲劳断裂可能与共振有关;另外,花键轴花键与机匣内花键啮合间隙不当和断裂处轴径尺寸偏小均为促进其扭转疲劳断裂的影响因素。     

低压转子钢30Cr2Ni4MoV扭转镦粗数值模拟

由于扭转镦粗较传统平砧镦粗对锻件施加了扭矩,从而降低了下压载荷,并且使得锻件变形更加均匀。利用DEFORM-3D软件对30Cr2Ni4MoV低压转子钢进行扭转镦粗模拟试验,同时优化工艺参数,证明扭转镦粗锻造法是一种有效改善锻件质量的工艺方法。     

60Si2Mn弹簧钢热变形行为研究

采用Gleeble-3800热模拟试验机对60Si2Mn弹簧钢进行热压缩实验,研究了试样在变形温度为900～1000℃、应变速率为0.5～10s-1条件下的动态再结晶行为.结果表明,在900～1000℃变形,不同变形速率条件下试样均发生了明显的动态再结晶,变形温度对再结晶的影响大于应变速率.本实验条件下60Si2Mn弹簧钢形变激活能为85.15kJ/mol.     

轿车悬架弹簧热处理技术和设备

阐述了轿车悬架弹簧全自动热处理生产线的组成特点,如采用先进的螺杆输送方式,使细长的弹簧钢棒料能在炉内连续地进行少无氧化脱碳的加热和输送。棒料加热后被绕成弹簧,利用余热淬火,再经过自动的排列和组合,在链式炉内进行回火、冷却和均热。均热过程是解决弹簧产品应力松弛的一项重要举措。生产线实现了规模产量,使弹簧的质量稳定,成本大幅度地下降。     

苏通大桥斜拉索用镀锌钢丝生产

介绍苏通大桥斜拉索用镀锌钢丝生产实践中的技术创新。通过技术分析,确定了"双张紧+限径模"工艺技术、"主导工艺+微调"整体优化技术、"三度控制"热镀锌操作技术3大关键技术,生产出了高强度(≥1 770 MPa级)、低松弛(Ⅱ级松弛率≤2.5%)、高扭转性能(扭转次数≥11)的桥梁斜拉索用镀锌钢丝。     

基于分离变量法的车用发动机配气机构弹簧动力学模拟

将气门机构的弹簧运动看作是连续弹性体的纵向振动,利用分离变量法建立了弹簧运动的数学模型,并通过实例分析,验证了此数学模型的合理性。     

Comparison of chemical, physical, micro-structural, and microbial properties of breads supplemented with sweetpotato flour and high-gluten dough enhancers

The objective of this study was to compare the chemical, physical, micro-structural, and microbial properties of breads supplemented with sweetpotato flour and high-gluten dough enhancers. Six breads, with and without dough enhancers (DE) and varying percentages of sweetpotato flour (SPF) were processed. Breads were stored at 22±2 °C, and samples were measured on Days 0, 2, 4, 6, and 8. Moisture, ash, fat, a_w, color, loaf volume, specific volume, density, texture, and weight loss were analyzed on Day 0, and β-carotene on the Days 0 and 8. The micro-structural and microbial properties of the sweetpotato breads were also compared. The fresh breads (Day 0) had moisture contents ranging from 36.66 to 41.56. β-Carotene was highest in breads containing 65% SPF. All breads were significantly (P<0.05) lighter in color by the last day of storage, while those containing 50% SPF with DE had the highest loaf volumes. Intact and damaged granules, cavities, and protein network were observed on the micrographs of the fresh breads. Further studies to include varying storage conditions, sensory, and consumer properties of the breads are needed.     

测井用偏心推靠器结构设计

介绍了测井用偏心推靠器的结构。板弹簧产生的贴壁力是影响测井效果的关键参数。以单弹簧偏心推靠器为例,计算了板弹簧厚度与贴壁力的对应值,可为偏心推靠器板弹簧的设计提供参考。为提高推靠效果,建议在水平井中采用双弹簧偏心推靠器。     

内插自振弹簧换热管传热性能试验研究

对6种不同几何参数的内插自振弹簧换热管和光管的传热及阻力特性进行了试验研究,结果表明,内插自振弹簧换热管的存在增加了对流体流动的扰动,破坏了管内侧的层流层,起到了扰流作用,提高了换热管的换热能力。内插自振弹簧换热管强化传热综合性能Nu/ξ1/3是光管的1.03～3.21倍,强化传热综合性能优于光管。     

热交换器的螺旋压缩弹簧在线自动除垢扰流新技术

螺旋压缩弹簧线自动除垢扰流新技术是在标准管式热交换器的换热管内插外套若干节螺旋压缩弹簧,使换热器在换热流体作用具有在线自动除垢的防垢,扰流强化传热,自洁高产等特异特性。