论文字数:17809，无损检测专业毕业论文
焊接缺陷超声定量测试方法研究
摘 要
随着现代工业的发展，对产品质量和结构安全性，使用可靠性提出了越来越高的要求，由于无损检测技术具有不破坏试件，检测灵敏度高等优点，所以其应用日益广泛。用无损检测方法对产品质量进行控制，使之在规定的使用条件下，在预期的寿命内，产品的部件或者整体都不会发生破损，从而防止设备和人身事故。
本文主要叙述在压力容器焊接缺陷安全评定工作中，焊接缺陷的定量分析结果至关重要，尤其是焊缝的裂纹类缺陷和未焊透缺陷。能否用常规无损检测技术较精确的测定压力容器对接焊缝中缺陷的高度，尤其是裂纹类缺陷将直接影响缺陷安全评定工作的可靠性。通过超声波检测方法研究，比较不同检测工艺的特点，制定相应的压力容器对接焊缝缺陷高度的测定方法和工艺，为缺陷自身高度的定量测定提供依据，为安全评定提供有效的缺陷几何尺寸。
关键词：缺陷，超声，定量
Study on ultrasonic quantitative test methods for welding defects
Abstract
With modern industrial development, more and more requirements are put forward to product quality, structure safety and operation reliability. As nondestructive testing (NDT) technology has advantage of not damaged specimen and high sensitivity detection, it has been used widely. NDT methods are used on product quality control and brought it under service conditions and expected life, the parts or overall of products do not damage, and thus the equipment and personal accident are prevented.
This paper describes welding defects quantitative analysis which is important in the safety assessment work of pressure vessel welding defect, especially in the crack of weld defects and incomplete penetration defects. Whether conventional NDT techniques can more accurately inspect the defect height in the butt weld of pressure vessels, especially crack, it directly affects the reliability of safety assessment work on defects. Through ultrasonic detection methods research, the characteristics of different test procedures are compared, and corresponding test methods and procedures on defect heights are formulated for pressure vessel butt weld. Thus the basis is provided for quantitative determination of welding defect height, and effective defect geometry dimension is provided for safety assessment.
Key words: defects,ultrasonic,quantitative
目 录
1 序言1
1.1 课题的目的和意义1
1.2 焊缝的超声波检测1
2 文献综述2
2.1 压力容器2
2.2 焊缝5
2.3 超声波技术10
2.4 目前压力容器焊缝缺陷超声定量存在的问题13
3 焊缝超声波检测工艺15
3.1 检测准备工作15
3.2 探测条件选择20
3.3 扫描速度（时基线比例）的调节25
3.4 灵敏度的调整和校准26
3.5 扫查方式的确定29
3.6 缺陷定位、定量及其定性29
4 实验内容35
4.1 检测对象35
4.2 仪器调节35
4.3 探头、耦合剂的选择与K值的测量36
4.4 距离波幅曲线37
4.5 探头扫查范围及方式39
4.6 缺陷定位40
4.7 缺陷定量40
4.8 缺陷定区域40
4.9 缺陷测长40
4.10 缺陷评级41
4.11 数据记录42
5 分析讨论43
5.1 超声波检测与射线检测结果比较43
5.2 超声波不同探头检测结果比较43
5.3 超声波检测存在的问题43
