Part Buyers Authority Issue #2

Executive summary: The growth of the transportation industry has increased casting production throughout North American foundries. This rise in production and the need for faster deliveries has led to an increase in casting defects – especially porosity defects after machining. Read how a recent foundry defect was discovered by the casting buyer and how this problem was resolved. • A red flag was raised after casting defects were discovered after machining • The OEM suffered delays due to an unexpected high reject rate at the foundry • Casting defects and delays are expensive for both the foundry and casting buyer • The OEM wanted to keep the job with that foundry • The OEM did not have foundry expertise in-house to understand and challenge the foundry process specifically for the castings ordered • The foundry was pressed by growth in orders and difficulties with labor retention • The foundry needed to establish new process controls to keep quality high and attract young labor with technologies • An audit on the foundry process was conducted by impartial foundry expert The measures on melt and mold design properties required for the specific castings were conducted by thermal analysis and casting process simulation, respectively. Sometimes the problem is in the mold design, sometimes it’s in the melt or mold properties, especially for sand molding. • It is important for both the casting buyer and the foundry to use metallurgical services to ensure quality. FRANÇOIS AUDET Director, SF FOUNDRY SOLUTIONS 14 PART BUYERS A U T H R I T Y Casting Buyers Need to Understand Porosity Technologies to Prevent Defects Figure 1: Shows two different ductile iron castings molded in sand with defects discovered after machining by an transportation sector OEM. The automotive OEM wondered, “What if I am buying more defective castings, that I’m not even aware of…”?