Steel Casting System Design Details
Casting system of steel castings is not like cast iron parts to fully consider the slag, inoculation and other aspects of the function, so the process personnel for the casting of steel castings system design details are often not too particular, especially for the selection of water position is often more casual. Steel Casting Therefore, caused a series of product quality problems, and even faced with these quality problems process personnel often habitually from the molten steel quality, process shrinkage and operation to find the cause, delay the quality of the problem. Shaoguan Cast steel plant in the pouring system design has traversed a lot of detours, Steel Casting but also accumulated a lot of experience to solve such problems.
Anchor lip products are typical thin-walled products, wall thickness is generally 20 30mm, the largest contour size 3500, material GS-45. 10 years ago our process in the control of the size and product wall thickness is very successful, but the gate from the inner circle of the mouth, Steel Casting the product poured out after the surface water is particularly serious, a channel groove, sand hole is also a lot.
Later, the gate is changed from the lowest product into the water, is placed into the water position of a small riser, the quality of the castings to improve the effect of the unexpected, the water problem fundamentally solved, sand hole also very rarely appear, products almost do not need welding repair. In accordance with the same process of thinking we later produced many types of anchor lip products, Steel Casting product quality has been very stable.
Impeller for the high head of the turbine generator products, blades for the water bucket shape, blade wall thickness is very thin, and uneven, the thinnest place only 3, the quality control of the blade position is very important. The material is Zg 20mn.
The initial pouring process is from the bottom of the inner wheel into the water, it is found that many of the castings water bad, leaving the size of the cavities and gap. Later, Steel Casting from the inner hub and the outer flange position together into the water, and raise the pouring temperature, blade position of the phenomenon still exists, and a number of blade bit sand phenomenon. Because the blade bit is too thin and in a few directions surface transition, the leaf bit quality problems are basically difficult to weld repair, a few consecutive products are reported, the loss is larger.
Improved pouring process: the lower part of the mold is provided with an annular pouring channel (equivalent to a transverse gate), and a gap gate is arranged from the lower portion of each blade to connect with the annular channel (Fig. 2. Shan). With the process of casting the impeller products, all the leaves are full, and sand holes are few cracks, the overall quality of the product has been greatly improved. Steel Casting Users of our production of impeller product quality very trust.
For step-shaped gate casting in the middle of the 90 's before the application is more common, such as hollow shaft, cylinder and other products have a certain height has been used. In the production practice, we find that the step gate has adverse effect on the intrinsic quality of the product, Steel Casting UT inspection or product deep processing often exposes more problems, and the phenomenon of clamping sand and slag is more common. On-site observation pouring process found that the upper gate always early into the water, causing the wall hanging cold steel and the surface floating on the molten steel into the molten steel, when the molten steel rises to close to the upper gate position, the upper gate often because of the early flow of molten steel discontinuous and seal dead not to the role of equilibrium temperature. Therefore, we gradually reduce the use of ladder-shaped gate, Steel Casting because the product structure needs to be used in the layered gate as far as possible relay pouring, even if the use of ladder gate to shorten the upper and lower distance.