1. The profile bay twists and twists and waves are caused by unreasonable die hole design, excessively fast extrusion speed, improper die hole lubrication, improper guide path or no guide path installed.
2. Bubbles and peeling due to the excessive wear of the inner diameter of the extrusion cylinder, the gap between the extrusion pad and the cylinder is too large; the extrusion cylinder and the extrusion pad are stuck with oil and sewage; the surface of the ingot has pores, sand holes, oil stains and the surface of the ingot is too rough ; Extrusion barrel temperature and billet temperature are too high, filling is too fast; the mold is oily during extrusion and other reasons.
3. Extrusion cracks Because the temperature of the extruded ingot is too high, the extrusion speed is too fast; the homogenization of the ingot is not good; the mold design is unreasonable, resulting in the excessive flow velocity difference between the center and the edge.
4. The pitting or pitting surface due to the high temperature of the cylinder and the ingot, the extrusion speed is too fast or uneven; the mold working belt is stuck with metal and is not smooth; the mold table belt is not hard enough or the working belt is wide; the ingot is too long, etc. Causes.
5. Scratches and ridges are caused by defects or ridges in the mold work; sharp edges and unsmooth mold blades; foreign objects on the work surface and uncleanness; hard inclusions in the ingots are blocked in the mold holes.
6. Unqualified size is caused by mold design errors or manufacturing defects; improper mold repair; excessive temperature rise of the ingot during extrusion, too much change in the extrusion speed; inaccurate calculation of the ingot length and insufficient fixed-length length.
7. Layering Due to the oil and dust on the surface of the ingot; the surface quality of the ingot is not good, and there are large segregation tumors; there are residual materials on the surface of the mold; the ingot itself is caused by delamination and bubbles.
8. Tail shrinkage It is caused by reasons such as leaving too short extrusion residue, oily or dirty extrusion gasket, unclean surface of the ingot, insufficient cutting length of the product, and sudden increase of the extrusion speed at the end of extrusion.
9. Unqualified performance. Because the extrusion temperature is too low, the profile cannot reach the quenching temperature; the artificial aging system is inappropriate; the instrument is out of control, the furnace temperature is too high or too low; the ingot structure is uneven, and the cooling air volume is insufficient.
10. Extrusion horizontal lines Due to the unreasonable mold design, the working belts of the same part are not of equal length; the extrusion speed is not properly controlled; the extruder is not running smoothly.