Effect of pouring temperature on defects of cast valve body
The figure shows the maximum porosity of a hydraulic valve body with cast material of QT500-7 as a function of […]
The figure shows the maximum porosity of a hydraulic valve body with cast material of QT500-7 as a function of […]
1.Simulation results and analysis of filling process The filling process of the casting is shown in the figure. It can
Based on the simulation of the valve body casting process, a hydraulic valve body model with casting defects is established
As one of the key components in the hydraulic transmission system, the working environment of the hydraulic valve is extremely
With hydraulic valve body as carrier, the filling and solidification process of valve body casting were studied by combining theoretical
Hydraulic valves are subjected to complex and variable loads during their operation. Therefore, the strength of the valve body must
In the process of casting simulation, the pouring system, grid division and calculation conditions are the same as the above,
The main valve holes of multi-way valves, change-over valves and other valves are thin, with many oil grooves and different
1. Defect category identification According to the shape and location of the stoma, the defect was initially identified as subcutaneous
The gray iron casting of a certain type of automobile engine block has a maximum outline dimension of 371mm ×
00bob cylinder is the key pressure bearing high temperature steel casting of supercritical steam turbine. Its function is to separate
The composition of slag inclusions is mainly composed of magnesium silicate, oxide, sulfide and sulfur oxide, which is a very
Although the upper and lower wall thickness of the cylinder is relatively uniform when casting the nodular iron ring, the
Formation mechanism of shrinkage cavity and porosity during solidification of castings The volume shrinkage during solidification is the cause of
Cast iron castings often have various casting defects. How to prevent these defects has always been the concern of casting
In cylinder casting, the subcutaneous pores are mainly distributed at the position of L ~ zmrn under the outer circular
1.The content of carbon, silicon, manganese, rare earth and magnesium must be appropriate. High carbon content can reduce the tendency
Causes: A. The composition of molten iron is unreasonable. B. Shrinkage cavity and porosity at the tensile position of the
The characteristics of spheroidization decline: good spheroidization before furnace, poor spheroidization on castings; or good spheroidization of castings poured first
1) The reasonable design of the riser, the heat preservation sleeve and the casting pouring system constitute the riser system,
In the casting of automobile parts, the wheel casting is a little different. Because it needs to meet a series
Features: The appearance of the casting is incomplete, with a crack like gap or broken flow, and the metal edge
Sand inclusion refers to that there is a layer of metal lump or sheet on the surface of the casting,
7 Discoloration and spots (1) characteristics: There are different colors and spots on the casting surface. (2) Causes: ① Improper
1) Prediction of shrinkage porosity and porosity Shrinkage cavity and shrinkage porosity are the holes that appear when the temperature
4.Casting deformation (1) characteristics: ① Overall deformation or local deformation; ② the geometric drawing of the die casting is inconsistent.
1 casting strain (1) characteristics: ① Along the opening direction, the surface of the casting shows a line like scratch
Features: the fracture surface of the casting is gray black, and the mechanical properties are obviously low. Through metallographic examination,
Thinking of solving die casting defects Because the causes of each defect come from many different influencing factors, so in
Features: a layer of clear and dense black spots can be seen on the upper surface of the fracture surface