In the field of automobile manufacturing, the quality and performance of casting molds play a vital role in the quality and reliability of the final product. Casting molds are not only basic tools for producing high-quality parts, but the presence of surface defects, such as flow marks and patterns, may have adverse effects on the appearance and performance of the product. Therefore, it is particularly important to deeply analyze the causes of flow marks and patterns and take effective solutions.

The generation of flow marks and patterns mainly comes from the following aspects. First, the temperature control of the mold is crucial. When the mold temperature is too low, the molten metal cools rapidly in the mold, which may form an uneven metal layer, leaving obvious flow marks. Secondly, the design of the runner also affects the flow of the molten metal. An unreasonable runner design, such as a shallow runner or an improper gate position, can easily lead to obstruction of the flow of the molten metal, forming turbulence, and leaving irregular patterns on the surface of the casting. In addition, the temperature and filling speed of the molten metal are also key factors. Too low temperature or too fast filling speed may lead to insufficient fluidity of the molten metal and the formation of patterns. Poor design of the mold exhaust system or blockage of the exhaust hole will also cause the gas to fail to be discharged in time, forming bubbles or patterns. Finally, improper use of coating on the mold surface, such as excessive accumulation, may form obstacles during the metal liquid filling process, resulting in flow marks and patterns.

In response to the above defects, enterprises can take a number of measures to solve them. First, it is crucial to ensure the suitability of the mold temperature. By preheating the mold to the optimal casting temperature, the fluidity of the metal liquid can be significantly improved, and the thermal stress caused by cooling can be reduced, thereby reducing the probability of flow marks and patterns. At the same time, regular inspection of the mold heating system to ensure its stable operation is the basis for ensuring casting quality.

Secondly, optimizing the runner design is also an important part of improving casting quality. Reasonable design of the runner depth, width, and the position and shape of the gate can ensure that the metal liquid flows into the mold evenly and stably, avoiding flow obstacles caused by complex design. In addition, adjusting the temperature and filling speed of the metal liquid, and reasonably setting parameters according to the characteristics of different metal liquids and casting process requirements can effectively improve the fluidity of the metal liquid and prevent the occurrence of turbulence.

Improving the exhaust system of the mold should also not be ignored. By increasing the number and size of the vent holes and adjusting the position of the vent holes to ensure that the gas inside the mold can be discharged in time, the appearance of bubbles and patterns can be effectively reduced. At the same time, regularly check the patency of the vent holes and clean up the blockages in time to ensure the normal operation of the exhaust system.

Finally, reasonable control of the amount and uniformity of the coating is an important measure to prevent flow marks and patterns. The right amount of coating can not only reduce the friction and adhesion between the molten metal and the mold, but also ensure the uniformity and appropriate thickness of the coating, avoiding defects caused by excessive accumulation of coating.