The ultrasonic testing standard for carbon steel, low alloy steel and martensitic stainless steel castings (astm-609 / 609m), ultrasonic testing of steel castings Part 1: general purpose steel castings (gb7233.1-2009), supply conditions of metal castings (din1690), ultrasonic testing of European steel castings Part 1: general purpose steel castings (en12680-1) were compared. Table 1 shows the general requirements of different specifications.
| Standard number | Thickness requirements | Material requirements |
| GB7233-87 | ≥ 30mm | Carbon steel, low alloy steel |
| GB7233-09 | ≤ 600mm | Non austenitic general purpose |
| ASTM-609/609M | / | Carbon steel, low alloy steel, martensitic stainless steel |
| SEP1922 | ≤ 600mm | Alloy and non alloy ferritic steel |
| EN12680-1 | ≤ 600mm | Ferritic steel |
In terms of casting defect classification, astm-609 / 609m specification divides casting defects into two categories: linear defects and nonlinear defects, while nonlinear defects include single defects and dense defects; As in din1690, gb7233-09 and en12680-1, casting defects are divided into two categories: planar defects and non planar defects. Non planar defects are divided into point defects (defects whose size cannot be measured) and extended defects (casting defects whose size can be measured).
| Quality grade | Cumulative area of defects in square inches (or corresponding square centimeters) | Minimum area scattered by dense defects in square inches (corresponding square centimeters) |
| 1 | 0 | 0 |
| 1-3 | 2（13） | 36（232） |
| 4-5 | 4（26） | 36（232） |
| 6-7 | 6（39） | 36（232） |
| 8-9 | 8（52） | 36（232） |
| 10-11 | 10（65） | 36（232） |
For the evaluation of casting defects, the acceptance standards of single defects and dense defects in astm-609 / 609m specification divide the casting defect level into 11 levels, and the defect location is divided into 1 / 3 wall thickness on the outside, 1 / 3 wall thickness on the inside and 1 / 3 wall thickness in the middle, reflecting the idea of treating defects in different areas separately. Dense defects are defined as two or more defects in a cube with a side length of 1 inch (25mm). Dense defects shall not exceed the quality level specified in the buyer’s order in Table 2. It is not allowed to exceed 1 / 3 of the wall thickness of the casting defect, and the loss of the wall thickness shall not exceed 1 / 3 of the thickness of the casting defect. In en12680-1 and gb7233-09, the acceptance level of point defects and the acceptance standard of extended defects are divided into 5 levels. The length measurement of casting defects in the wall thickness direction adopts the method of reducing 20dB, and the size of casting defects shall not exceed 15% ~ 20% of the wall thickness. The location of casting defects is also defined. The location of casting defects is also divided into outer 1 / 3 wall thickness, inner 1 / 3 wall thickness and middle 1 / 3 wall thickness. Among them, the middle 1 / 3 wall thickness is the core wall, and the outer 1 / 3 wall thickness and inner 1 / 3 wall thickness are collectively referred to as the outside. For spot defects, the operability of directly measuring the number of casting defects in the evaluation frame may not be as strong as astm-609 / 609m, because for dense spot defects, such as shrinkage porosity, extremely dense small holes will appear in a small range. In terms of key areas of concern, focus on variable cross-section, external cold iron, repair welding area and important outer layer. These areas should be detected by double crystal straight probe and angle probe. Compared with the previous casting defect evaluation form in gb7233-09, it can be found that en12680-1 is referred to. For point defects, din1690 also directly measures the number of casting defects in the evaluation frame, but in terms of bottom wave attenuation limit, for the area with quality grade 2 ~ 5, local bottom wave attenuation is allowed to be zero. In addition, din1690 allows cracks for castings with quality grade of 5. In principle, cracks are not allowed for castings with quality grade of 2 ~ 4, unless fracture mechanics can prove that cracks have no effect. The allowable cracks are shown in Table 3.
| Wall thickness s | Allowable crack length |
| ≤10mm | 7 |
| 10 ~150 mm mm | 2/3 s |
| >150mm | 100 |