Inspection of extruded profiles

[China Aluminum Network] inspection items for kneading profiles include chemical composition, room temperature mechanical function, scale error, appearance quality, low magnification arrangement, microscopic arrangement, and special function inspection (corrosion resistance inspection, ultrasonic inspection, fracture inspection, and resistance Rate check). Aluminum alloy profiles only check the chemical composition, room temperature mechanical function, scale error and appearance quality. In addition to inspection of chemical composition, room temperature mechanical function, scale error, appearance quality, general aluminum aluminum alloy profiles should also check the low magnification arrangement, quenching Finished products should be microscopically arranged for inspection, and special requirements for aluminum alloy profiles should also be checked for corrosion resistance (anti-stress corrosion, anti-fatigue and anti-shedding), ultrasonic flaw detection, fracture inspection, and resistivity inspection. . Inspection items and sampling rules are shown in Table 6-2-1.

Table 6-2-1 kneading profiles inspection items and sampling rules

Inspection items

Checking nature

Sampling regulations

chemical composition

Factory inspection

No less than 1 per melting or batch (per 1,000kg of merchandise)

Room temperature mechanical function

Factory inspection

2 batches (furnace), 1 each

Scale error

Factory inspection

L% per batch, not less than 10

Appearance quality

Factory inspection

View by root

Low magnification

Factory inspection

2 batches (furnace), 1 in each kneading tail

Microscopy

Factory inspection

2 batches (furnace), 1 each

Stress corrosion resistance

Special features

Check 2 batches (furnace), 1 each

Anti-fatigue corrosion

2 batches (furnace), 1 each

Anti-shedding corrosion

2 batches (furnace), 1 each

Ultrasound

View by root

Fracture

2 batches (furnace), 1 each

Resistivity

2 batches (furnace), 1 each

First, the scale inspection

The inspection of the dimensions of the kneading profiles is divided into custom-scale inspections and special-scale inspections. Inspection of aluminum profiles for construction and decoration and general industrial aluminum alloy profiles includes inspections of section dimensions, viewpoints, plane voids, surface voids, tortuosities, twists, lengths and end cuts, and special industrial kneading Profiles should also be checked for special dimensions such as tortuosity (narrow face tortuosity), deflection, and suspension twist. The number of samples to be inspected is shown in Table 6-2. Each lot is 1% and not less than 10, and special scales can be checked one by one and qualified deliverers.

Aluminium alloy construction profiles can refer to GB5237.1 "aluminum alloy construction profiles top some: substrate" rules to meet the standard error of general industrial aluminum alloy heat kneading profiles according to GB/Tl4846 (aluminum and aluminum alloy kneading Rule Dimensional Errors) The rules are fulfilled.

1. Routine scale inspection

1) Inspection of cross-section dimensions The cross-sectional dimensions of the kneading profiles can be checked by measuring instruments such as micrometers, vernier calipers and feelers. The acceptance error of profile section dimensions is divided into three grades: general level, high-precision level, and ultra-high-precision level. The acceptance error level of section section dimensions is generally agreed upon by the supply and demand sides and specified in the drawings, but there are scales for installation. , It promised to use high-precision or ultra-high-precision level errors. When the cross-section scale requirement approval error is high-precision and ultra-high-precision, its promised error value should be indicated in the product drawing. The figure does not indicate the allowed error value, but the scale of the directly measured part, the error of its acceptance Perform at the general level.

Conventional section profiles can be inspected with micrometers, vernier calipers, and other metrological tools. However, with regard to fine sections with high section or special scale errors (see Figure 6-2), it is very difficult to use conventional viewing methods and viewing tools. Accurately examine the profile section dimensions. With the development of science and technology, especially the development of electronic technology, the cross-section inspection of aluminum alloy profiles can not only be manually measured with conventional micrometers, vernier calipers, etc., but also can be used for automatic or semi-automatic fine-section inspection. The profile section scanner was used to examine the section dimensions.

Scanners are divided into two-dimensional scanners and three-dimensional scanners, which can be selected according to the needs of viewing. With regard to the inspection of section dimensions of conventional kneading profiles, a two-dimensional scanner is generally used. The section scanner is mainly composed of a scanning device and a computer processing device. The inspection process is as follows:

(1) Sawing is performed on the sample using a fine sawing machine to expose straight, smooth, shiny, and less burrs;

(2) Degreasing and drying the end surface of the sample with a degreasing agent;

(3) A section scan of the end face of the finely sawn profile;

(4) Use the computer's profiling program to measure the cross-sectional scanning pattern.

The main functions of the scanner are as follows:

1 Directly scan the section of the profile and directly measure the dimensions of the section of the profile on the scanning pattern;

2 After scanning the cross-section of the profile, after comparing with the corresponding standard drawing, use the software of the accounting machine to directly calculate each scale of the profile section and its error value;

3 After the direct scanning of profiles, and converted to CAD pattern graphics for mold design and production;

When using a scanner to measure the cross-section dimension of the profile, it should be noted that the end face of the sample should be smooth and smooth. There should be no burrs or debris. The end face should be straight in the kneading direction, otherwise the accuracy of the measurement will be affected.

2) Use the all-round view ruler to measure the view point and tip cut.

3) Plane gap Place the ruler horizontally on any plane of the profile. The larger gap between the plane of the profile and the ruler is the plane gap of the profile. See Figure 6-2-2 (B is the profile width).

4) Curved voids will be close to the specification template on the surface of the profile, as shown in Figure 6-2-3. The larger value of the chord length of 25 mm is not exceeded 0.13 mm for the profile surface and the normative template, and 25 mm for some lack of 25 mm. When some of the central angles of the cross-sectional arc are greater than 90°, the chord length of the central angle of 90° plus the chord length of the remaining central angles should be determined. Need to see the profile of the surface void, be noted on the drawing or in the contract. The specification template for viewing the surface voids is supplied by the demander.

5) Tortuosity The tortuosity of the profile is to place the profile on the channel, and when the tortuosity is stabilized by gravity, the underside of the profile measured along the length of the profile and the larger gap (ht) of the channel, or a 300 mm long ruler Along the length of the profile against the appearance of the profile, the measured value of the larger gap (hs), as shown in Figure 6-2-4 (L is the length of the profile length).

6) Twisting degree When placing the profile on the channel and pressing it tightly at one end to make it stable, measure the greater distance IV between the bottom surface of the profile and the channel along the length of the profile and subtract from the IV value. The twist value after the twist is the twist degree, as shown in Figure 6-2-5. When measuring the degree of twisting, one end of the profile shall be tightly fixed on the channel, and make the plane of the end profile fit in the channel. Under the condition of stable weight, the plane of the measurement profile shall be lifted off the height of the channel at the other end. This difference is determined by dividing the height difference by the width of the plane.