针对圆形缺陷数量已知且需对焊缝缺陷进行评级，采用Visual C++面向对象设计原理，对JB/T 4730.2—2005中钢、镍、铜制承压设备熔化焊对接焊焊接接头质量分级中的圆形缺陷等级评定标准进行程序设计。建立单文档应用程序，插入对话框菜单，在对话框中添加下压按钮控件函数、编辑框控件函数和成组框函数，将设计的程序进行调试和编译，生成了可视化界面。输入母材公称厚度和圆形缺陷数量两个变量，系统可自动评定圆形缺陷的等级。试验结果表明，该自动评级程序设计合理，运算结果准确。

Aiming at the defects of known number and the requirement for weld defect ratings, the design of a program was proposed to use Windows application design principle for JB/T 4730.2—2005 steel, nickel, and copper melt pressure equipment welding butt welding joint for the purpose of classification of round defect levels evaluation criteria. Through establishing the application documents, inserting a dialog box in the menu, pressing the button control add function, editing box control function and group box function, and followed by the procedure of debugging and compiling, it shall generate a visual interface. By inputting the mother material nominal thickness and round number two variables, the defect evaluation system shall automatically show you the level of defects. The experimental results show that the automatic rating program design is reasonable, the operation result is accurate.