Pacifi c Steel produces the raw casting and delivers a machined part to Cast Connex. The bolt holes are drilled by end users onsite.
Producing the Part The steel connectors are cast in a
four-step process. First, the molten steel (2,850F) is poured into the as- sembled sand mold and allowed to cool and solidify in the mold. After cooling, the casting is removed and shaken out of the sand mold. Next, the risers are cut off and the riser stubs and fl ash lines are ground smooth. Finally, the casting is shot-blasted for improved surface appearance. Heat treatment of the connectors is
a critical process step to produce the required microstructure, mechanical properties and Charpy impact values. The castings are heat treated per the ASTM A958 specifi cation (1,700F aus- tenitizing, water quench and 1,150F temper cycle). Following heat treating, the outside
faces of the two plates are milled to the required fl atness and thickness. The weld shoulder is an as-cast feature, while the holes in the connectors are machined by the end users to match their bolt pattern and connection con- fi guration in their structural design. Quality assurance for these struc-
tural components is driven both by building codes and specifi cations and requirements. Testing and inspection in production includes tensile tests and Charpy V-notch tests on test blocks from each heat, visual examination per
Online Resource
Visit
www.sfsa.org/tutorials/ index.html for an interactive version of this tutorial, as well as other conversion case studies.
JANUARY/FEBRUARY 2010 METAL CASTING DESIGN AND PURCHASING 33
ASTM A802, magnetic particle examina- tion per ASTM A903 and ultrasonic ex- amination per ASTM A609. First article components were also radiographically tested to the procedures prescribed in ASTM E446 and ASTM E186.
METAL About the Authors
Carlos de Oliveira is chief executive offi cer of Cast Connex Corp., Toronto, Canada. Ryan Grant is a technical sales representative for Pacifi c Steel Casting Co., Berkeley, Calif. Steve Gonczy, Gateway Materials, Mount Prospect, Ill., compiled the material for online publication.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60