Process flow of stainless steel jewelry casting

Process flow of stainless steel jewelry casting: Stainless steel jewelry casting process is usually to produce irregular shaped jewelry, including rings, pendants, bracelets and other special-shaped pieces.

1. Because stainless steel casting cools and solidifies faster in the metal mold than in the sand mold, and the metal mold has no tolerance, so when the metal mold is cast, the casting stress generated in the casting is larger than that of the sand casting, and the crack tendency is also large. It is easy to produce defects such as insufficient pouring, cold insulation, and white mouth (for castings). usually:

(1) The following structural problems should be paid attention to in preventing insufficient pouring and cold isolation in stainless steel casting: A. The shape of the casting should be as streamlined as possible to avoid sharp edges and sharply changing connections, so as to facilitate the flow of molten metal ;B. The wall thickness of the casting should be appropriate and not too thin, especially when the contour size of the casting is large; C. Large horizontal planes should be avoided, because it makes the molten metal rise very slowly when the casting is poured, and The air contact surface is large and easy to oxidize. At the same time, due to the fast heat dissipation of the metal mold, the liquid metal quickly loses its fluidity, which is easy to cause defects such as insufficient pouring, cold isolation, and slag inclusion;

(2) The following structural problems should be paid attention to in preventing cracks in stainless steel casting: A. Ribs, bosses, etc. should be set up for structurally weak parts to be strengthened to prevent casting cracks; B. When arranging reinforcement ribs on castings, also Its influence on the shrinkage of the casting should be considered; C. Protruding parts such as bosses, ribs, flanges, etc. that hinder the free shrinkage of the casting should be minimized; D. The wall thickness should be uniform, the transition and connection between the walls should be moderated, and the corners should be moderated. The requirements of appropriate rounding and other aspects should be stricter than those of sand casting; E. The vertically connected walls should be changed to inclined connections.

2. When designing the basic structural unit of stainless steel casting and its parameters selection, it is usually necessary to pay attention to: (1) In order to prevent the occurrence of white cracks in gray iron castings, in addition to taking technical measures, the wall thickness must not be too thin (Some information points out that when the wall thickness is more than 15mm, the corners of metal mold castings must be rounded. For aluminum alloy and magnesium alloy metal mold castings, the casting fillet should not be less than 3-4m. For cast iron, The casting fillet of cast steel and copper alloy metal mold castings can be selected by referring to Table 1.1-32; (2) Since the metal mold and the core have no tolerance, in order to facilitate the removal of the casting and the extraction mold, the casting slope of the metal mold casting should be It is appropriately larger than the sand casting, generally 30%-50% larger. It should be pointed out that the casting slope is not only related to the type of alloy and the height of the wall, but also to the position of the surface of the casting. The surface of the casting that has a tendency to detach from the surface of the metal mold can be designed with a smaller slope, and the surface of the casting that tends to be pressed on the metal mold when the casting shrinks should be given a larger slope. The casting of stainless steel castings of various alloys (3) Due to the fast heat dissipation of the metal mold, the minimum wall thickness of stainless steel casting should be larger than that of sand casting, and the minimum wall thickness of various casting alloys and castings of different sizes; (4) The inner wall and inner rib of the casting The thickness of the casting should generally be 0.6-0.7 of the thickness of the connected outer wall, otherwise, due to the slow cooling of the inner wall (rib), cracks may easily occur at the junction of the inner and outer walls when the casting shrinks.

3. When designing stainless steel castings with complex shapes, if the production process has great difficulties, the shape of the castings should be simple and the strong structure should be changed without affecting the use conditions of the castings, so as to facilitate the removal of the castings from the metal mold.

Contact Us

• No. 18, Xinhe Road, Xiaobian, Chang’an Town, Dongguan City, Guangdong Province
• +86 18829906820
• info@cfenjewelry.com