The solidification of Guangdong alloy steel castings is very important for castings. Generally, the solidification method of castings is divided into two methods: layer-by-layer solidification and paste solidification according to the nature of the metal material; according to the casting structure, it is divided into two methods: sequential solidification and simultaneous solidification. Here I want to remind everyone that this layer-by-layer solidification and paste solidification are the properties of the material, and it is related to the solidification interval of the metal material, or in other words, the crystallization interval. The solidification zone refers to the area where the liquid and solid two phases coexist in the molten metal; this so-called crystallization interval is the temperature difference between the liquidus and the solidus of the molten metal. The temperature range determines the way the alloy solidifies.

This is the inherent property of the material. When the material is selected, its solidification method is also selected and determined. The latter two solidification methods have nothing to do with the metal material, and are mainly determined according to the structure of the casting. In order to obtain dense castings, according to the structure of the casting, a method is found from the casting process to force the casting to adopt a certain solidification method. So, what does it mean to solidify layer by layer, as the name suggests, is to solidify layer by layer. That is to say, the solidification zone of molten metal is a line. The solidification of pure metals or eutectic component alloys crystallized at a constant temperature is layer-by-layer solidification. Simultaneous solidification, as the name implies, means that all parts of the entire casting solidify at the same time.

The solidification zone of the casting is very wide, and even during a certain period of solidification, the solidification zone runs through the entire section of the casting. So, what is sequential solidification and simultaneous solidification? The so-called sequential solidification is to artificially change the order of one's own solidification, so that the casting can be solidified according to the process design requirements. First casting, then gate, and finally riser, so that the shrinkage cavity in the Guangdong carbon steel casting is transferred to the riser, and then a dense casting is formed. At the same time, various methods are adopted to reduce the temperature difference of each part of the casting to make All parts of the casting solidify at the same time (regardless of its size and structure). This is the first point.

The second point, some people may understand that the material solidified layer by layer should adopt the principle of sequential solidification; while the material solidified in paste should adopt the principle of simultaneous solidification. Is this statement correct? No! This is what we said above. Layer-by-layer solidification and paste solidification are the properties of the metal material itself, you have no choice. If the customer has determined the material of the casting, this one means that he is already fixed. The sequential solidification and simultaneous solidification are determined by you, that is, the craftsman. I don't know if I said that you are not clear, but I think a considerable number of people have confused this issue, so it is necessary to repeat it here. In other words, castings designed with materials solidified layer by layer can adopt the principle of simultaneous solidification according to the structure; castings designed with materials solidified in paste form can adopt the principle of sequential solidification.

The third point, under normal circumstances, gray iron, low carbon steel, industrial copper, aluminum, and aluminum-silicon alloys are all solidified materials layer by layer. Nodular cast iron, high-carbon steel, aluminum-copper alloy, aluminum-magnesium alloy, magnesium alloy, etc. are all pasty solidification methods. There is another problem that needs everyone to pay attention to, that is, the temperature difference in the section of Guangdong stainless steel castings, or the temperature gradient. When the temperature gradient is large, the paste-like solidified material may also become solidified layer by layer.