GB/T 34370.2-2017Nondestructive testing of amusement equipments-Part 2:Visual examination (English PDF)

3.1 Visual examination

7.1

Equipment and apparatus used for visual examination include: apparatus used for direct visual examination, remote visual examination, and translucent visual examination.

7.2

Apparatus for direct visual examination mainly includes: lighting sources and low-power magnifiers.

8.2 Verification of examination process

It shall use verification samples to verify the visual examination process specification. The verification sample may be a thin wire having a width of less than or equal to 0.8 mm or other similar artificial defects. The verification sample shall be placed on the surface of the piece under test, or on the surface with similar lighting condition, surface structure, contrast ratio, and accessibility, etc.

as the piece under test; and shall be placed on the position of the area under test which is most difficult to be observed.

When the FACTORS of examination technique, observation method, surface structure of the piece under test, surface lighting requirement of the piece under test, or verification sample which have a serious influence on the examination sensitivity CHANGE, the process specification shall be re-verified.

8.3 Examination process card

For the visual examination of each type of equipment or workpiece, based on the actual situation, in accordance with GB/T 34370.1, this Part, and the general examination process specification, a visual examination process card shall be developed. The process card shall include at least the following:

a) Process card number;

b) Executive standard for examination;

c) Information of the workpiece under test: name, model, number, material, specifications, welding type, etc.;

d) Examination position and accessibility;

e) Surface state of the piece under test;

f) Examination equipment and apparatus;

g) Lighting conditions;

h) Examination timing;

i) Verification of examination process;

j) Examination procedures (steps);

k) Signature and date of developers and reviewers.

9.2.3 Lighting conditions

In order to achieve the best examination results, the lighting conditions shall meet the following requirements:

a) MAKE the direction of lighting ray reach the best angle relative to the observation point;

b) Avoid surface glare;

c) Optimize the color temperature of light source;

d) USE an illumination level which is compatible with the surface reflected light;

e) At least 500 lx of illumination shall be achieved on the surface of the piece under test. For areas which must be carefully observed or are found to be abnormal and require further observation and examination, at least 1000 lx of illumination shall be achieved.

9.2.4 Visual examination of welded joint

For newly-manufactured welded joints, attention shall be paid to solder skips, cracks, burn-through, incomplete penetration, porosity, collapse, severe undercuts, incompletely filled weld, slag inclusions, and other appearance deficiencies. Special attention shall be paid to the deficiencies which may arise from welding of dissimilar materials and special welding processes. See

Appendix A for typical visual deficiencies in steel fusion welded joints. Appendix

B gives pictures for the typical visual deficiencies.

For welded joints in service, it shall focus on important welded joints, pay attention to cracking (arc starting place, alternating load, stress concentration), corrosion, rust, paint peeling positions. Especially craters, pores, and poor molding positions which exist in the manufacturing process shall be examined.

9.2.5 Visual examination of parts

9.2.5.1 Bolt

Observe the bolts for bending deformation, damage, wear, and rust. USE a 10 times magnifier to observe whether the bolt, especially bolt head and thread root, has cracks.

9.3.2

Remote visual examination can be performed using mirrors, telescopes,

endoscopes, optical fibers, cameras, video systems, automatic systems, robots, and other suitable visual aids.

9.3.3

Remote visual examination shall have at least the resolution comparable to direct visual examination. If necessary, it shall verify whether the remote visual examination system can meet the requirements for examination work.

9.4 Translucent visual examination

9.4.1

Translucent visual examination requires a directional light source of sufficient intensity to uniformly pass through the position and area under test, to meet the requirements for examination of deficiencies in transparent and semitransparent materials.

9.4.2

The ambient ray must be recognized in advance. The reflected light or surface glare from the surface under test shall be smaller than the applied transillumination light passing through the position and area under test.

9.5 Examination records

The visual examination records shall include at least the contents specified in 8.3 and Clause 11.

10.1 General principles

10.1.1

All examination results shall be evaluated in accordance with the relevant regulations, executive standards, and (or) contract requirements of amusement equipment.

10.1.2

The examination process specification of this Part specifies minimum examination requirements; but does not limit the more demanding examinations which may be performed during production and use.

10.1.3

When the abnormality is found by visual examination, and the nature and influence of the abnormality cannot be judged, other testing methods such as thickness measurement, hardness measurement, metallography, magnetic particle, or penetration may be used to detect and evaluate the abnormal position.

10.2 Welded joint

10.2.1

All overlaps and slags, etc. of welded joints shall be removed.