Valve parts were more difficult to machine the valve is installed on the main parts of the structure, more complex shapes, and some parts are thin-walled, long and thin pieces, poor rigidity. However, normalizing treatment will cause a large internal stress than the annealed, only applies to the carbon content of less than 0.35% of the cast steel products. Because low-carbon steel casting plastic is good, not easy to crack when cooling.

In the machine tool machining, positioning and fixture are more difficult, so often a complex dedicated folder with the valve components, positioning precision of a lower base level, the higher surface roughness, and sometimes even non-machined surface location. Because steel castings under cast that exist within the pores, cracks, shrinkage, and shrinkage, coarse grains, organization and uneven residual stress and other casting defects, so that the strength of steel parts, especially the plasticity and toughness greatly reduced. The valve sealing surface of the geometric shape accuracy and surface roughness demanding, so they increased the difficulty of machining the valve. At the same time, valve materials, cutting poor, and gave the valve processing methods, tool material, cutting parameters, technical equipment, etc. has resulted in many new problems.

For the grain refinement, uniform within the organization and eliminate stress, steel pieces must be normalizing or annealing. Normalizing treated steel, its mechanical properties after annealing than the high, costs low, it used more often. Each wax mold injection pressure, injection wax time, holding pressure time, automatic control, eliminate the human factor, the wax mold quality is stable. Each mold through the tunnel, the cooling time is adjustable to achieve automatic control of mold cooling time. Running from mold to mold or self-table position can be manually transported operation.

automotive castings china: http://www.fotai-china.com/pros/pro17.htm

Valve parts were more difficult to machine the valve is installed on the main parts of the structure, more complex shapes, and some parts are thin-walled, long and thin pieces, poor rigidity. However, normalizing treatment will cause a large internal stress than the annealed, only applies to the carbon content of less than 0.35% of the cast steel products. Because low-carbon steel casting plastic is good, not easy to crack when cooling.

In the machine tool machining, positioning and fixture are more difficult, so often a complex dedicated folder with the valve components, positioning precision of a lower base level, the higher surface roughness, and sometimes even non-machined surface location. Because steel castings under cast that exist within the pores, cracks, shrinkage, and shrinkage, coarse grains, organization and uneven residual stress and other casting defects, so that the strength of steel parts, especially the plasticity and toughness greatly reduced. The valve sealing surface of the geometric shape accuracy and surface roughness demanding, so they increased the difficulty of machining the valve. At the same time, valve materials, cutting poor, and gave the valve processing methods, tool material, cutting parameters, technical equipment, etc. has resulted in many new problems.

For the grain refinement, uniform within the organization and eliminate stress, steel pieces must be normalizing or annealing. Normalizing treated steel, its mechanical properties after annealing than the high, costs low, it used more often. Each wax mold injection pressure, injection wax time, holding pressure time, automatic control, eliminate the human factor, the wax mold quality is stable. Each mold through the tunnel, the cooling time is adjustable to achieve automatic control of mold cooling time. Running from mold to mold or self-table position can be manually transported operation.

automotive castings china: http://www.fotai-china.com/pros/pro17.htm