Large stainless steel castings in precision casting, there are inevitably holes and other defects, and some holes will be particularly small, in the quality of large stainless steel castings inspection will be particularly inconvenient. Because of this, it is very important to know the types of holes in large stainless steel castings.

Next, let's introduce in detail the types of holes commonly seen in large stainless steel castings

1) The intrusive holes in large stainless steel castings are usually large in volume, and most of them are round, oval and pear shaped. In the pear shape, the tip of the pear is the air entering the specific position. The surface of such holes is smooth, glossy or slightly oxidized. Most of the invading holes are located on the upper surface of the casting, close to the surface of sand mold and core, and occur singly or locally. Sometimes, the air bubbles entering will flow or float with the molten steel, which makes the specific position of the holes uncertain. Therefore, it is possible to find holes in other specific positions of the casting.

2) In large-scale stainless steel castings, the precipitated holes are mostly small round spherical or crack like polygonal, sometimes discontinuous or mixed, and often coexist with shrinkage porosity. When there is less air in the steel, the precipitated holes are crack like, and when the air content is high, they are round and spherical. The precipitated holes are usually distributed uniformly in the cross section of the casting, and most of them are near the riser, dead corner of large stainless steel casting and later solidification. Because this kind of hole is caused by the air precipitated from the molten steel, once this kind of hole occurs in a large stainless steel casting, most of the large stainless steel castings poured in the same furnace or ladle will also have such holes.