JB/T 7927-2014Valve Cast Steel Visual Quality Requirements (English PDF)

3.1

Cast steel shall be inspected after cleaning, dressing and painting, compared with the surface of cast steel according to the photos specified in this standard (see Clause 5), and evaluated for various defects.

3.2

This standard collects 12 types of surface defects (see 5.1 to 5.12, and each defect type includes 5 example photos represented by A, B, C, D and E. In each defect, 2 example photos of A and B indicate that defects of this degree are acceptable (qualified), and 3 example photos of C, D and E are unacceptable (unqualified) defects. The guiding principles of this standard shall be considered acceptable for defects that are significantly smaller than unacceptable defects.

3.3 This standard photo comes from the actual casting

The photo shows the surface defects of casting. Each type of surface defects can only be judged by comparing the series of photos of the same type.

3.4

In view of the possible problems if the same standard is used to judge castings with large differences in specifications and wall thicknesses, the photos provided in this standard are examples of drawings specifying the actual dimensions of any 100 mm × 125 mm area on the surface of castings.

4.1

This standard provides 60 rating photos showing various casting defects that can be seen by visual observation. The description of all defect types [type a) ~ type 1)] in the rating photo is only applicable to surface defects, not internal defects.

4.2

The types and characteristics of various surface defects are described as follows:

——Type a) Crack: Linear cracking on the surface of cast steel due to internal and external stresses. Generally, obvious surface cracks are unqualified.