共查询到20条相似文献,搜索用时 109 毫秒
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通过微观形貌和成分分析研究了低碳铝镇静钢经氮氢罩式炉退火处理后冷轧钢板表面出现的丝斑缺陷。结果表明,无丝斑缺陷的钢板表面均匀光亮,钢板表层无异常的碳元素富集;有丝斑缺陷的钢板表面明显发黑、呈丝带状,缺陷部位呈岛状或线状,异常元素是石墨碳,在钢板表层一定深度范围内碳元素含量明显高于钢板基体。 相似文献
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为了有效利用脉冲涡流信号的低频成分检测钢板内部裂纹缺陷,提出了脉冲涡流同步采样方法。介绍了该方法的工作原理;采用在钢板上加工不同规格矩形槽的方法模拟钢板的裂纹缺陷;设计了由激励线圈和检测线圈构成的传感器,实现脉冲涡流信号的提取;采用数据采集卡采集信号,以Labview为平台,实现同步采样方法的软件设计。对钢板缺陷的检测和试验数据的分析,证明了脉冲涡流同步采样方法在钢板内部裂纹缺陷检测中具有较高的灵敏度,可以有效识别钢板内部裂纹缺陷。 相似文献
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对严重影响钢板表面质量的钢板表面"水波纹"缺陷进行了分析研究。结果表明,氧化铁皮清除不净,高压水喷嘴搭接不好,轧辊硬度偏低,预矫直机压力过大,都会导致水波纹缺陷的产生。通过采取降低钢坯加热温度、更换轧辊材质、提高轧辊硬度、改进高压水除鳞方式及结构、降低预矫直机压力等措施,有效抑制了钢板表面水波纹缺陷的产生,提高了钢板表面质量。 相似文献
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介绍了一种210通道钢板缺陷100%超声波在线检测装置;详细介绍了超声波检测装置的平面布置、机械结构、电控设备的系统配置、传动系统配置、电气设备布置、设备工艺原理、技术指标和功能等。该钢板缺陷100%超声波检测装置,其头部探伤和尾部探伤均采用钢板固定、探头移动的方式;边部探伤可沿板宽方向进行调整以适应不同的钢板宽度,在探伤过程中随着板形对钢板边部进行跟踪浮动探伤;实现了壁厚的全覆盖探伤,达到了钢板缺陷100%超声波检验及工况要求。 相似文献
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基于数值模拟的厚板精冲挤压过程分析 总被引:1,自引:1,他引:0
针对厚板精密冲裁过程存在的缺陷(塌角与毛刺等),基于Deformed2D分析了10mm厚钢板精密冲裁过程中双齿V形压料板对冲裁质量的影响.采用V形压料板可在一定程度上减小塌角的高度,但不能完全消除.随后采用精冲挤压方法对这一厚板的成形过程进行了分析,结果表明:采用精冲挤压成形工艺后,厚板零件表面塌角得到了完全消除,零件... 相似文献
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通过对火焰切割法取样的热轧Q345B钢板进行拉伸、常温冲击、硬度和金相组织检测试验,得到了距离火焰切割线不同位置试样的力学性能,研究了加工余量对钢板力学性能的影响。结果表明,热轧Q345B钢板距火焰切割线1.5 mm范围内,其显微组织受到了影响;取样加工余量大于5 mm时,钢板力学性能及硬度不受影响。因此,减小火焰切割加工余量可以提高钢板综合成材率。 相似文献
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In this paper, a multi-particle microfinite element model with a random particle distribution in SiCp/Al composites was developed using ABAQUS software. The formation mechanism of edge defects near the exit of orthogonal cutting was analyzed, and the effects of cutting parameters on the sizes of edge defects were investigated. The results indicate that both the brittle fracture of SiC particles and the plastic flow of Al matrix occur in the process of the edge defects formation. Additionally, the cutting speed has little effect on the sizes of edge defects but the cutting depth has a significant effect on the height and length of edge defects. The numerical results were also compared to the orthogonal cutting experimental data and found to be in reasonable agreement. 相似文献
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微电子用玻璃基板加工过程中需要将来料的大板玻璃切割分断成小板,以往采用机械定位的方式,通过定位治具与工件进行机械接触,工件的侧边受到定位治具的压力,易发生形变或者因外力产生崩口或裂痕等缺陷,良品率较低。针对上述问题,设计了基于视觉定位的玻璃基板切割分断生产设备,论述了玻璃基板切割分断机构设计的整体方案、结构组成、视觉定位系统的功能及控制流程。上料搬运、切割和分断过程中分别采用线阵相机识别系统进行初对位和自动对位,减少了单片玻璃的边破和角破,提高了单片玻璃的边缘质量。 相似文献
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纳米切削会造成工件的内部微观缺陷,这种缺陷会引起残余应力的变化进而影响工件的表面质量,而这种缺陷结构与切削层初始温度有密切联系。为降低工件纳米切削加工制造中的缺陷,采用分子动力学的方法,构建了含有切削层的单晶铜纳米切削模型。首先,通过分析工件结构体积及微观缺陷的变化确定了切削层的适用初始温度;其次,分析了切削层初始温度对切削力的影响,并在不同初始温度和切削力作用下对单晶铜位错和晶格等微观结构的变化进行了分析;最后,通过实验对仿真结果进行了间接验证。结果表明:单晶铜切削层初始温度的可选范围为293~400 K;在此范围内,随着切削层初始温度的升高,切削力大小变化显著,但波动平稳,晶格结构的转变速度也随之增快;当切削层初始温度设为360~390 K范围内时,单晶铜工件的表层微观缺陷相对较少,由此可预测单晶铜工件在此初始温度范围内加工得到的表面质量较高。 相似文献
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Research on the cutting thermodynamic behavior of high-strength large-thickness offshore jack-up platform leg rack
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The cutting of offshore jack-up platform leg rack is highly nonlinear and complex thermal processing process. The residual stress influences the following welding quality and cause crack growth. Therefore, research on the cutting practice of jack-up platform leg rack is significant to improve the safety and reliability of the offshore platform. A heating source model that is applicable to the cutting and emulation of high-strength thick plates han been presented. Then, the thermo-physical characteristic parameters of NV E690 leg plate was calculated by JMATPRO, and is revised according to the theory of metallographic. Furthermore, the numerical simulation of the linear cutting of leg plate was conducted, and the reliability of the heating source model and the thermo-physical characteristic parameters of material were proved by comparing them with the experimental data. Based on the former study, the optimal parameter (heating source, cutting speed and radius of the heating source model) which ensured that the gear plate was cut through without edge collapses during cutting was calculated. The optimized process parameters can be used to study the distribution of residual stress in gear plate during cutting which provides theoretical guideline for improving the construction technology of offshore platform legs. 相似文献