Steel castings, surface roughness is an important factor in the quality detection of stainless steel castings, stainless steel surface roughness factors very much, such as stainless steel material of the coarse problem, or stainless steel castings in the production process of the casting process, let's detailed information about the reasons and methods to improve the surface roughness of stainless steel:
Reasons for surface roughness of stainless steel castings:
1, from the first material, stainless steel castings, surface roughness of a large part of the reason is the quality of the stainless steel itself to the surface of the stainless steel, with columnar crystal structure of network skeleton, with a refractory material, additive and water filling in the middle of the frame, but in the dry roasting surface has a pore size of liquid metal penetrate into the pore size of these, resulting in rough surface of stainless steel, causing the phenomenon of rough surface of stainless steel castings.
2, manufacturing industry, casting stainless steel castings casting process is an important link, the roughness affects stainless steel temperature, pouring temperature and pressure head, the vacuum pouring process parameters on the casting surface, especially the effects of mould temperature and pouring temperature is larger.
3, alloy, small thermal conductivity, in the use of stainless steel after pouring molten metal into a type of slow cooling and casting coarse grains prepared by concave grains makes the casting surface roughness, the grain boundary groove depth may reach 7 M.
4, press type and the surface quality of investment mould. The surface roughness of investment casting is the most important part of the surface roughness of casting. It is also related to the quality of pressing surface, the method of pressing and pressing process parameters.
Method for improving surface roughness of stainless steel castings:
1, improve the smoothness of the surface of stainless steel, stainless steel is the influence factors of surface roughness of liquid metal into the stainless steel surface gap, crystal diameter, surface pore average diameter, surface curvature radius of liquid alloy will is an important factor affecting the liquid metal penetration depth, so as to obtain the smooth surface of the stainless steel castings to reduce crystal and the particle diameter decreases, the surface pore diameter Lujiang; or the enrichment on the surface of the additive, the larger pores filled, in order to reduce the penetration depth of liquid metal.
2. The relationship between the temperature of stainless steel and the pouring temperature of metal liquid and the surface roughness of casting. With the increase of temperature and pouring temperature of metal liquid, the filling property of molten metal is improved, the depth of infiltration into the surface pores increases, and the surface roughness of stainless steel castings increases.
3, deal with the alloy modification, and the good thermal conductivity of zircon filler to improve the cooling speed of steel castings, the casting surface layer grain is small, to reduce the surface roughness of castings.