Our next meeting is February 21, 2013 2pm to 4pm
Registration: $40 per person ($20 Dinner and $20 donation to the Scholarship Fund)
AT: Canmet MTL
183 Longwood Road South, Hamilton
Cast Differently II
Since the highly successful, and sold out, Cast Differently seminar at Canmet in February of 2012, Bob Puhakka has been working with casting facilities in Canada, the USA, Australia, Finland, India, Brazil, and England, teaching them how to produce vastly superior castings for their customers and achieving inefficiencies in their productivity.
Locally, Cast Differently partnered with Custom Aluminum Foundry in Cambridge, Ontario. Together, they’ve been working furiously to position CAF as the world’s preeminent gravity aluminum metal casting facility.
This year’s seminar will introduce and reaffirm the latest concepts in metal casting technology and explain how foundries can implement superior practices that will make a dramatic impact immediately, regardless of what alloys they are pouring.
Pub Supper at Kelsey’s 4:30 pm to 7:00 pm
Main Street West (Just around the corner from Canmet)
The Chapter has a room reserved for a chance to network, ask questions, and meet new friends.
AFS Ontario Meeting January 17, 2012
Mohawk Foundry Laboratory On Line Auction
The recent on line auction of equipment left over from the integration of the Mohawk lab facilities into Canmet was a great success. There were 92 bidders and all the equipment was sold for a total of $76,495. this money will go to FEF Canada to set up an endowment Scholarship. The CFA/AFSOntario would like to thank auctioneer John Green who not only did a great job but also waived his commission.
Mohawk Canmet Partnership
The integration of Mohawk’s lab facilities into Canmet is a win win situation. It gives Mohawk students the ability to make use of one of the finest foundry lab facilities in Canada. Once the final stage of commissioning the equipment is completed Canmet will have full scale industrial capacity.
The Mohawk/Canmet partnership has completed three projects with industry and has three more projects in progress. This partnership is more than Mohawk and Canmet. It also partners with Government for funding, industry, Canmet-research and Mohawk-education.
Presentations at Canmet
Canmet Research on Porosity and Embrittlement in Steel Castings.
Presented by Dr. Selçuk Kuyucak
Porosity in Steel Castings Contributing Factors
Gas-related porosity forms a few mm below the surface, whereas shrinkage porosity tends to form in the interior of a casting. The major sources of gas uptake are from returns and the melting operation. Also, air aspiration and/or entrainment may take place during pouring.
Dissolved gases only needs to exceed the solid solubility limit at the solidus temperature.
CA6NM Martensitic Stainless Steel is a versatile steel for oil and gas pipeline valves and
fittings. In CA6NM nitrogen accumulates in the returns and results in sub-surface porosity when the concentration exceeds 200 ppm.
Effect of Zr Addition to CA6NM – 0.1% Zr is sufficient to elevate returns ratio to 75%
Not all nitride formers are equal: Ti additions caused pin holes from H2 pick up.
Sub-surface porosity is pre-dominantly gas related and forms when solubility limit in the solid at the solidus temperature is reached. To prevent sub-surface porosity limit returns use and use nitride formers in de-oxidation practice.
Embrittlement in AusteniticManganese Steels
This is a Hadfield’s steel having 1.2% C, 13% Mn. It is a Hypereutectoid steel but the desirable, nonequilibrium structure is 100% retained austenite. It is solution annealed at 1060°C and water quenched to room temperature.
Hadfield steel is used in heavy industrial equipment and thick sections are common. The austenite grains are subject to intergranular carbide embrittlement on slow cooling.
Two distinct types of carbide form. The “thin” carbides appear as grain boundary delineations. Their cementite phase is not resolved under light microscope even at high magnification (1000x). The “thick” carbides show cementite phase and cementite / austenite phase boundaries at 200x magnification. Transition from a thin to a thick carbide is not gradual but step-wise.
Model for Carbide Precipitation
Thin carbides are metastable and have a good match with the austenite matrix. This leads to a low energy interface and a low barrier for nucleation. Thick carbides are the stable constituents but have a high energy interface and a high barrier for nucleation. Discrete, metastable thin carbides nucleate rapidly at the grain boundaries, whose Mn and Cr content are similar to those of austenite matrix, giving rise to delineations under a reflective microscope. When thin carbides grow to a critical size their growth is stumped because of lattice mismatch. Nucleation of a more stable, thick carbide becomes favorable. The thick carbide thus formed grows rapidly in continuous film, incorporating any thin carbides along its way. Its growth in the normal direction slows down after a micron or so thickness, because of the required diffusion of Mn, Cr and Si.
Chromium increases the rate of harmful carbide formation. However, carbide-formers such as Cr slow down the carbide formation by the solute-drag effect. Cr leads to the intermediary “thickened” carbides that form almost as rapidly as the “thin” carbides, but are harmful to toughness.
A method of measuring quenching efficiency was outlined as a process control tool to ensure satisfactory castings are obtained.
Conclusions
A model for carbide formation in austenitic manganese steels distinguishes between “thin” and “thick” carbides and “thickened” carbides in grades having 2% Cr
A technique for measuring quench time can be used as a process control tool to ensure sound castings
Applications of Improvement Techniques in Foundry and Alloy Developments Presented by Dr. Delin Li
Dr. Li discussed structured problem solving and basic statistics. He also presented casting example and projects.
There are Six Problem Solving Steps
1. Identify major problems – Brainstorming, Pareto Graphs, Check sheets, Consensus, PDSA, Management tools.
2. Define the problem – If it’s large, break it down to smaller ones and solve one at a time – Fishbone, Process flow, Pareto, Check sheets, Rational Sub-grouping, Systematic troubleshooting.
3. Investigate the problem – Collect data and facts, Check sheets, Graphs, Histograms, Control charts, Scatter diagram, Cp.
4. Analyze the problem – Find all possible causes, Decide major ones, Brainstorming, Check sheets, Graphs, Fishbone, Statistical Inference, Histograms, DOE, Management tools.
5. Solve the problem – Choose from available solutions, Select one that has the greatest benefit for everybody, Implement the solution, Brainstorming, Check sheets, Consensus, Pareto.
6. Confirm the results – Was the problem fixed? Make sure it stays fixed, Control Charts, Histograms, Check sheets, Pareto.
Design of Experiments (DOE)
DOE Objectives
1. Generate knowledge about a product or process
2. Seek to find the effect of a set of independent variables on a set of dependent variables
3. Comparative objective – Is a factor significant?
4. Screening objective – Select the few important effects?
5. Optimizing responses
6. Optimal fitting of a regression model objective
DOE Check List and Practical Considerations
• Include all important factors, per engineering and operator judgment.
• Avoid factor settings for impractical or impossible combinations. At least one replicate.
• Include all relevant responses.
• Run “dabbling experiments.”
• Check the performance of gauges such as gauge R&R.
• Record everything that happens.
• Analyze and interpret the results.
• Minitab software may be used for DOE.
Dr. Li demonstrated the use of DOE in solving casting problems such as Alloy Development, Process Improvement and Casting Defects.
Summary
The structured problem solving methods can be powerful for foundry improvements.
DOE can be effectively used for screening, comparative, optimizing, and regression objectives, in the areas of process improvements and materials development.
Current steel casting projects include steel cleanliness, mach inability, and grain refinement, using the above improvement techniques and innovation approaches. There are collaborations between Wescast and Canmet for these projects.
YOUR ELECTRONIC INGATE
Note: As long as we have your correct email address you should get your copy of the Ingate. If you or if anyone you know who is a paid up member of the Ontario Chapter did not receive their issue of the Ingate please contact us at afsontario@bell.net
INGATE SUPPORTERS
The Board of the AFS Ontario Chapter would like to thank all who have supported us in the past by their business card ads and hope you will continue with your support in the coming year. If you have not yet sent us your business card and would like to advertise in the Ingate (and also on our website) please contact us at afsontario@bell.net. Please note the funds donated from advertising go towards scholarships for students interested in our industry. If you see errors or have changes to make with your ad, please contact us so we can correct it.
AFS ONTARIO CHAPTER LIBRARY
The AFS library has an excellent collection of the latest editions of our industries literature and foundry information. The AFS resource base is the most comprehensive collection of foundry information in the world. In addition to books, video and CD’s are also available. Remember, you get the best price available when you purchase or order through the chapter library.
ROSTER CORRECTIONS
We ask that you check your membership roster for errors. Please note that the information in the roster is detail we receive from AFS headquarters in Chicago. We can assist with any corrections by contacting our Membership Chairman, Vince Skinner and he will forward to the Chicago office. You can email Vince with your changes at vskinner@penalloy.com
AFS ONTARIO WEB SITE
We have a new look and new features on our web site. By checking our site you can keep abreast of what is happening with our chapter. It also allows you to quickly access our sponsors’ web sites. As always we are open to your suggestions for improvements both with our web site and the Ingate. You can send your comments to afsontario@bell.net
INDUSTRY CALENDAR
January 24, 2013
. AFS Detroit Chapter Management Night
February 20, 2013
. AFS Southeastern Regional Conference
February 26 – 28, 2013
. Society of Manufacturing Engineers (SME) HOUSTEX
February 28 – March 1, 2013
. AFS Wisconsin Regional Conference
CMI Course Schedule
** For more information please visit www.afsinc.org and click on “Cast Metals Institute”. The Cast Metals Institute provides intensive, specialized education for metal casters by metal casters. Since its beginning in 1957, CMI has presented over 3,000 courses to 65,000 participants representing nearly 5,000 individual companies – dramatic evidence of the acceptance of CMI as a vital contributor in the continuing development of foundry personnel.
