If steel did not have the property of plastic deformation, the only ways to make parts from it would be casting or cutting into shape.
No deformation processes like cold heading, cold rolling, swaging etc. would be possible.
Slip planes in the metallic crystal explain Plastic Deformation and Plasticity in Steel. This makes cold working processes like cold drawing possible.
If one subjects a piece of steel to a heavy load, the material will measurably stretch. When the load is removed, if the steel goes back to its original dimension, the deformation that it underwent when the weight was applied is called “elastic deformation.” In this case, the steel did not take a permanent “set.”
If one subjects a piece of steel to a much greater load, if, when the load is removed, the steel does not ‘spring back’ or recover to its original dimension, the new shape or dimension is a permanent deformation. (It is often said to have ‘taken a set,’) This is called “Plastic Deformation.”
Plastic Deformation is explained by the movement of planes of atoms from their normal positions.
Steel and most industrially useful metals are able to withstand a great deal of this Plastic Deformation before they break.
Brittle metals will just fracture under such loads;
Cold drawing of steel is a process that applies a load to the metal to make the atoms in the steel take new positions with respect to each other, resulting in lowered ductility, increased tensile and yield strength and new dimensions or shape. These in turn, are often helpful in improving the machinability of the steel, allowing you to more economically produce the parts and components that are essential for our current technologies.
Most people think of steel’s hardness as its main advantage. The facts of the matter are that it is steel’s plasticity or ability to plastically deform that makes it such a useful and versatile material for humankind.
LCCC Fab Lab- Year of the Dragon was a great CAM project for their students.
From my encounters in retail with recent graduates, just making change without a cash register is a difficult task.
Let alone using the Pythagorean Theorem to control geometry, runout, and cosine error.
Four year college graduates lack the skills we need in our shops more often than not.
Nothing wrong with being able to quote Yeats, but does it pay as much as being able to set up and operate this equipment?
Yet we have openings for people with skills.
Last night, 26 Northern Ohio Chapter members of the PMPA attended an open house of the advanced manufacturing labs at Lorain County Community College:
CAD Lab
Fab Lab
CNC Machining Lab
Welding Lab
Computer Integrated Manfacturing Lab
Manual Machining Lab
Our attendees were impressed with the equipment; they were quite impressed by the instructors.
They were delighted to sense the confidence, understanding, and capability shown by the students at work in the labs.
We may not know where the entire skilled workforce for our precision industry will come from, but we know some local programs where we can find some skilled technicians.
The machinability of steel bars is determined by three primary factors. Those factors are 1) Cold Work; 2) Thermal Treatment; 3) Chemical Composition.
Machinability is the result of Cold Work, Thermal Processing and Chemical composition- as well as the ability of the machine tool and the machinist.
Cold Work improves the machinability of low carbon steels by reducing the high ductility of the hot rolled product. Cold working the steel by die drawing or cold rolling results in chips that are harder, more brittle, and curled, prodcuing less built up edge on the tools cutting edge.. The improved Yield to Tensile Strength ratio means that your tools and machines have less work to do to get the chip to separate. Steels between 0.15- 0.30 wt% carbon are best machining; above 0.30 wt% the machinability decreases as carbon content (and hardness) increase.
Thermal Treatment improves the machinability of steel by reducing stresses, controlling microstructure, and lowering hardness and strength. While this is usually employed in higher carbon steels, sometimes a Spheroidize Anneal is employed in very low carbon steels to improve their formability. Stress Relief Anneal, Lamellar Pearlitic Anneal, and Spheroidize Anneals are the treatments applied to improve machinability in bar steels for machining.
Chemical composition is a major factor that contributes to the steel’s machinability or lack thereof. There are a number of chemical factors that promote machinability including
Carbon- low carbon steels are too ductile, resulting in gummy chips and the build up of workpiece material on the tool edge (BUE). Between 0.15 and 0.30 wt% carbon machinability is at its best; machinability decreases as carbon content increases beyond 0.30.
Additives that promote machining include
Sulfur combines with Manganese to form Manganese Sulfides which help the chip to break and improve surface finish.
Lead is added to steel to reduce friction during cutting by providing an internal lubricant. Lead does not alter the mechanical properties of the steel.
Phosphorus increases the strength of the softer ferrite phase in the steel, resulting in a harder and stronger chip (less ductile) promoting breakage and improved finishes.
Nitrogen can promote a brittle chip as well, making it especially beneificial to internal machining operations like drilling and tapping which constrain the chip’s movement.
(Nitrogen also can make the steel unsuitable for subnsequent cold working operations like thread rolling, crimping, swaging or staking.)
Additives that can have a detrimental effect on machining include deoxidizers and grain refiners.
Deoxidizing and grain refining elements include
Silicon,
Aluminum,
Vanadium
Niobium
These elements reduce machinability by promoting a finer grain structure and increasing the edge breakdown on the tool by abrasion.
Alloying elements can be said to inhibit machinability by their contribution to microstructure and properties, but this is of small impact compared to the factors listed above.
You could just send your part CAM files to one of those online services to just make the parts and ship them to you. Sounds pretty high tech. Sexy. New school. No humans involved.
Or you could send them to a company that actively involves its human engineering talent to add value for you, the customer. Old school. And worth it!
Imagine the cost of both the material lost by turning and the machine time to remove it if this were made from barstock of the greatest diameter.
Two of the major contributors of a part’s cost are material and machining time.
Value engineering at Fairchild Auto-Mated involves engineers evaluating each part to seek ways to reduce these cost factors.
Imagine, engineers getting involved in evaluating your part before production begins.
Decidedly Old School. And decidedly worth it.
The valve component shown above was presented to Fairchild made as one piece carved out of oversize barstock in an single piece.
Fairchild’s engineers studied the design, application, and function.
They determined that this part would be less expensive to produce as two separate items assembled and staked together to form this single part.
This design eliminated the costly stock removal of large diameter (expensive) stainless steel, and reduced the amount of (expensive) stainless steel chips produced to generate the stem.
There was no need for the disk portion of this part to be stainless, and so less expensive and more machinable brass was selected for this part of the component.
What was the pay off for value engineering versus the “download the file over the internet and have it go straight into production” process path.
At $1.00 saved per part, the Customer saved one of these for every 100 parts they purchased thanks to Value Engineering.
The savings identified by Fairchild’s value engineers resulted in a total cost savings of over $1.00 per part.
End result for the customer: $48,000 in savings the first year…
If you just want to email your part file to someone and have them make it with no humans involved, well, that is certainly your perogative.
But if you would like to have the benefit of a value engineering teams design review that can find, say, $1.00 per part in cost savings- then you probably ought to make a different decision.
Old school shops like Fairchild have been able to survive through all of the ups and downs in the market- because they continue to add real value and identify real savings for their customers.
And in quantities of 50,000 or more per release, that value engineering can add up to real money.
How do you know your part is optimized for production?
How do you identify real cost savings besides just having jobs rebid?
Do you have a process to involve your suppliers in value engineering?
Or do you just go with lowest bidder for the part as drawn on the print?
Where can you go to find information about available federal programs without having to waste time and resources navigating the federal bureaucracy?BusinessUSA
Find opportunities to sell to the Federal Government.
BusinessUSA is a platform for you to access services you may need to grow your firm and succeed: technical assistance to start a business, access to financing, assistance in exporting and more.
BusinessUSA combines information and services from 10 different government agencies through one consolidated website and coordinated telephone support through a single 1-800 number.
The BusinessUSA website already presents hundreds of business resources, in one place.
Looking for opportunities to supply your products to the US government, its agencies, or contractors?
(Guest post by PMPA MemberDarlene Miller. BusinessUSA is a result of proposals made by the Presidents Council on Jobs and Effectiveness, of which Ms. Miller is a member.)
I’d be very careful trying “Facetime” when this “Apple iPhone” Single Gas Burner Stove is working!
It says it's an iphone right on the label!
The good news is that these ‘Apple iphone’ stoves are being confiscated by Chinese Government officials.
But not because of Intellectual Property Law Violations.
They are being pulled because they are UNSAFE.
So when someone starts to tell you about how things are improving in China for IP protections and that China is becoming more a nation ruled by ‘law”- my advice is to maintain a healthy sense of skepticism.
From what we see when laws are enforced, they are enforced selectively, and almost always against the ‘foreigner’ with the deepest pockets.
We were priveleged to have had a face to face meeting with Director Michaels of OSHA earlier this year.
We brought up the topic of harsh regulatory tone.
Director Michaels characterized the agency as ‘small and needing strong means to remain effective.’
We congratulated him on the agency’s success at portraying themselves as aggressive regulators.
The OSHA website has this to say:
“OSHA is a small agency; with our state partners we have approximately 2,200 inspectors responsible for the health and safety of 130 million workers, employed at more than 8 million worksites around the nation – which translates to about one compliance officer for every 59,000 workers.”
Before getting too sympathetic, a review of some facts might be in order:
Penalties doubled!
Actually average proposed penalties are up by 102%
Both Bark and Bite are big! OSHA statistics reveal that the average proposed penalty for a Serious violation doubled from $1,053 in 2010 to $2,132 in 2011- a 102% increase!
OSHA Budget is up!
FY 2011: $573,096,000
FY 2012: $583,386,000
Although by Washington DC standards a little over half a billion dollars and an increase of $10.3 million dollars probably doesn’t seem like much money at all.
“Dr. David Michaels, Assistant Secretary of Labor for OSHA, recently stated that the higher penalties are still too low when compared to other regulatory agencies. He defended the higher penalties as an important tool in OSHA’s overall efforts to increase enforcement. In our view, this increase comes as no surprise and employers can expect even higher penalties in 2012 and beyond. “
OSHA seems to be taking this size thing to heart!
Since higher penalties remain an important tool and are still too low, and since OSHA cannot practically visit all 7 million workplaces it makes sense for employers to proactively address OSHA compliance.
When OSHA arrives, they will be itchin’ to do a great job.
The first place to start would be how does a small agency prioritize its enforcement resources?
Inspection Priorities!
1. Imminent danger situations—hazards that could cause death or serious physical harm— receive top priority.
2. Fatalities and catastrophes—incidents that involve a death or the hospitalization of three or more employees—come next.
3. Complaints—allegations of hazards or violations also receive a high priority.
4. Referrals of hazard information from other federal, state or local agencies, individuals, organizations or the media receive consideration for inspection.
5. Follow-ups—checks for abatement of violations cited during previous inspections—are also conducted by the agency in certain circumstances.
6. Planned or programmed investigations— inspections aimed at specific high-hazard industries or individual workplaces that have experienced high rates of injuries and illnesses— also receive priority.
For more on these inspection priorities consult the OSHA Fact Sheet link below.
Back to Basics!
Train your people in
Personal Protective Equipment,
Lockout- Tagout,
Right To Know Haz Comm,
Slips Falls Tripping Hazards,
Machine Guarding,
Powered Industrial Trucks ,
Electrical- Wiring and General,
You can intelligently manage your risk of OSHA Enforcement and penalties by asking yourself these three questions and then doing something about them:
Do you have a process for managing safety?
Is it followed?
Is it effective?
As employers we have a general duty to maintain a safe workplace. Let’s take our duty seriously. You know the folks from OSHA will.
