The Common Problem of Stainless Steel Casting Parts

Date:16-01-2018

What are the common defects of Stainless Steel Casting Parts, what is the reason for it, let's understand the following together. Shrinkage: stainless steel casting parts appear irregular shape of the thick cross-section of the hole, shrinkage of the rough wall; shrinkage: casting cross-section of the small and scattered shrinkage. Reason: Casting system or riser set is not correct, unable to make up or insufficient shrinkage: pouring temperature is too high, the liquid metal shrinkage is too large; casting design is not reasonable, uneven wall thickness and can not make up: cast iron in C, Si Less content, prone to shrink alloying elements.

Blowholes: holes with grit inside or on stainless steel casting part. Causes: sand strength is not enough or no tight weeks. Cavities, casings within the system does not blow the net, when the sand-type squeezing the local crowded, pouring system unreasonable, red sand type. Slag porosity: The upper surface of the casting is filled with slag holes, often coexist with pores, in different sizes, clustering. Reason: Pouring temperature is too low, flooding is not easy to float: did not block the molten slag pouring: pouring system is not correct, slag the role of poor. Sticky sand: the surface of the casting adhesion of a layer of sand and metal mechanical mixture, so that castings rough surface. Reason for the sand too loose, cavity surface is not dense. Pouring temperature is too high, liquid metal penetration. Grit is too coarse, the gap between sand is too large.

Sanding: scar sheet metal surface produced by the protrusions, so that the surface roughness, sharp edges and sandwiched between the metal sheet and casting sand. Reason: sand heat and humidity intensity is low. Cavity surface is easy to swell or crack after being heated and expanded. Sand type of local compaction is too large, too much water, moisture prone to peeling after drying. The runner is too concentrated, so that the sand bake week powerful. Pouring temperature over pouring too slow.

Thermal cracking: cracking of castings, severe oxidation of the cracked section, dark blue Appearance twists and irregularities, cold cracking, cracked section is not oxidized and shiny, sometimes slightly oxidized. Causes: Sand concessions casting contraction caused by excessive internal stress. Gating system improperly opened up. Hinder casting shrinkage. Casting design is unreasonable, big difference between the thickness.