The blue bar segments in the following graph shows us that as the baby boomer cohort leave the workforce, there are currently not enough under 25 and 25- 34 year olds to make up for their loss. This means that not only will productivity increases have to continue, but also that we need to really make an effort to bring 34 and under people into our skilled workforce in manufacturing. This will certainly be a challenge for employers, and if nothing is done, will mean a new management version of the No Job Blues– “the no skilled worker blues” – for our shops as we try to find candidates for open positions left by the departing boomers.
If you are a savvy shop, you are working on this issue today- if the average age of our manufacturing workers is 50, that means over half of our workforce are within a few short years of retirement.
What’s your plan for workforce and skill development in your shop, city, region and state?
Scratches are longitudinal or near longitudinal indentations caused by mechanical rubbing of the bar on protrusions as it is processed.–AISI Technical Committee on Rod and Bar Mills, Detection, Classification, and Elimination of Rod and Bar Surface Defects
I’d bet dollars to donuts that there were sparks on the mill where this product was in contact with something during rolling.
Scratches are detected visually and are caused by unintentional contact with build up on mechanical parts and mill components during rolling. Scratches typically have a more rounded bottom and less scale than a seam or crack.
They can range from small, sharp indentations, to broad gouges with partially projecting edges. The metal that is displaced by the mechanical working often appears to be of an undetermined structure. This is usually referred to as a Bielby layer.
Hot roll scratches can ‘fill in’ during cold drawing as the drawing process displaces steel into the depression. The bright surface, lack of scale and lack of decarb under the metal so moved are evidence that the are beneath the displaced material was pickled or descaled and so the displacement ocurred during cold drawing and the scratch pre existed that operation. This metal can then flake off, (usually during straightening) prompting a call that the material has slivers. The correct identification remains scratch.
A foreign object (wire) or material build up in the cold drawing die can result in a bright scratch on the resulting cold drawn bar.
The sample that inspired this 1986 entry into my Lab Notebook was caused by the bar scratching on some build up on the mill’s exit table.
While a scratch should be rejectable as a “mechanical defect” the fact is that most scratches seldom exceed the depth for minimum stock removal limits.
Scratches are generally found on softer materials.
Due to their larger radius, scratches seldom open up during upset or torsion tests.
In my experience most mill hands will call any longitudinal imperfection a seam, so many times scratches are falsely described to be seams.
Economic activity in the manufacturing sector expanded in May for the 34th consecutive month, and the overall economy grew for the 36th consecutive monthFabricated metals was one of 13 sectors reporting expansion in May.
According to ISM’s Bradley J. Holcomb, “The PMI registered 53.5 percent, a modest decrease of 1.3 percentage points from April’s reading of 54.8 percent, indicating expansion in the manufacturing sector for the 34th consecutive month. The New Orders Index continued its growth trend for the 37th consecutive month, registering 60.1 percent in May. This represents an increase of 1.9 percentage points from April and also the highest level recorded by the index since April 2011. The Prices Index for raw materials fell to 47.5 percent in May, dropping 13.5 percentage points from April, indicating lower prices for the first time since December 2011. Comments from the panel generally reflect stable-to-strong orders, with sales showing steady improvement over the first five months of 2012.”
The dropping of the price index for raw materials is noteworthy, being the first such drop since December 2011.
Certainly the global uncertainty is likely to affect our markets in the coming months, but for now North American Manufacturing continues to lead the recovery.
PMPA’s Business Trends Report for the first four months of the year is consistent with The latest ISM report and indicates that the industry’s 2012 average shipments will likely finish up 8 to 9 points higher than last year.
Every stapler in our office is black and metallic silver. Or grey.
Except for two red staplers.
This red stapler better be at the copier – Or Else!!!
While visual management is generally thought of as a way to error proof manufacturing processes, the use of visual management techniques can be applied in the office as well.
The red staplers are deployed at our copier and fax machine- our office ‘commons.’
You might think that they are red so that they will be easily spotted.
While that would be true, that is not why they are so colored.
The real reason for the red color is to provide a clear visual signal that they were out of place if someone walked off with them, since all other staplers in our office are shades of metallic and black.
So a missing ‘commons stapler’ would have someone “Seeing Red!”
But they are never missing, the visual difference alone seems to be self enforcing.
The case of missing shared tools or supplies is called the tragedy of the commons, and it is one of the more interesting concepts from my college career.
Although my Malthusian Eco-Freako Professors would be aghast to find out it applies to the mundane utensils of everyday office work.
If you have a problem with shared resources or “commons issues”- understanding the “tragedy of the commons’ concept and that visual lean techniques can help to protect the ‘commons’ is an idea worth pursuing.
What kind of visual lean techniques have you deployed in your office or shop that have made a difference in resource availability?
A colleague asked me “Why am I standing in line at the restaurant if there are so many in the unemployment line?”
I told him that we were standing in line with the 91.7% of the folks who are employed, not the 8.3% who are unemployed (U-3 unemployment measure).
I should have told him that we were standing in line with the 85.2% of folks who are fully employed, as opposed to the 14.8% who are not (U-6 unemployment measure).
Blue line indicates those of us who are standing in line at Applebees, Red line indicates people suffering from the “jobless recovery.”
The blue line shows the average number of hours worked by people with jobs in the private sector. It shows that those of us who are working are doing fine.
The red line in the chart below is a monthly index of the employment-to-population ratio, normalized to a value of 100 in December 2007, when the recession began. The lack of an uptick in the redline since 2009 is, we think, the essential tale.
Regardless of how one chooses to explain it, the fact that it has not improved is the critical issue.
We recall Dicken’s opening line from A Tale of Two Cities:
“It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to heaven, we were all going direct the other way – in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only.”
Sobering fact: Long term unemployment, defined to be 27 weeks or more out of work climbed to 5.4 million, or 41.3% of unemployed(U3) people.
It takes quite a bit of coordination to prepare and turn around a hotel ball room for lunch, a keynote address, and then setup tabletops for exhibits in the same afternoon.
Here’s a 2 minute 49 second time lapse look at how its done.:
A tip of the hat to the folks at the Westin Chicago North Shore who made it possible.
And the PMPA member companies who so generously share the time and talents of their key people to staff our program planning committee.
Americans Paying More in Taxes than for Food, Clothing, and Shelter
In 2012, Americans will pay approximately $4.041 trillion in taxes, which is $152 billion, or 3.9 percent, more than they will spend on housing, food, and clothing.
Scabs are irregularly shaped, flattened protrusions caused by splash, boiling or other problems from teeming, casting, or conditioning.-AISI Technical Committee on Rod and Bar Mills, Detection, Classification, and Elimination of Rod and Bar Surface Defects
Scabs are always present prior to rolling.
(Teeming refers to the process of filling an ingot mold with molten steel from the ladle. We’ll point out some continuous casting analogs later in this post.)
Scabs have scale and irregular surfaces beneath them; they tend to be round or oval shaped and concentrated to only certain blooms or billets. Scabs are always the same chemistry as the steel bloom or billet.
(If the gross irregular surface protrusion characteristic is appearing on all product, it is not likely to be a scab. If the protrusion is a different analysis, it is likely to be mill shearing.)
To differentiate between scabs and rolled in scale, scabs are ductile when bent while scale is brittle and crumbles.
If the protrusion is brittle, it may be rolled in scale.
Scabs are primarily an ingot process issue related to teeming, but we have seen them on continuous cast products as a result of mold and tundish anomalies.
Scabs present with scale beneath; Cracks may (but are not always) be present associated with the scab due to stress concentration causing the material underneath to crack. (Not the crack causing the scab…)
Ingots or blooms showing scabs should be conditioned to remove the scabs. Thermal conditioning of billets (hot scarfing or torch conditioning) can sometimes leave artifacts which present as scabs upon rolling.
While scabs can be confused with slivers, shearing, rolled in scale, or tearing, their ductility eliminates them as rolled in scale. Scabs are distinct from shearing as scabs are isolated by occurrence and have an irregular surface beneath them, while shearing usually presents as multiple instances in a single orientation along the bar. Tearing is characterized by chevron shaped breaks rather than oval shaped protrusions.
We remember that not all returned from “that cause for which they gave the last full measure of devotion.”
We remember…
Many of the people in our industry have served in the armed forces.
Some of our companies have employees on active duty.
Some of us have family serving.
You may have sung the Star Spangled Banner a thousand times. You may have heard it 10,000 times.
But you hear it with your whole body when it is your daughter or son that is deployed.
This Memorial Day, we will remember.
We are not at war.
Our politicians are not at war.
Some of our employees, some of our sons and daughters are at war.
This Memorial Day, we will remember.
We will show we are grateful for their service.
This memorial day we hope that you remember too:
“…that these dead shall not have died in vain, that this nation under God shall have a new birth of freedom, and that government of the people, by the people, for the people shall not perish from the earth.”
Excerpts from Abraham Lincoln’s Gettysburg Address
“Seams are longitudinal crevices that are tight or even closed at the surface, but are not welded shut. They are close to radial in orientation and can originate in steelmaking, primary rolling, or on the bar or rod mill.”– AISI Technical Committee on Rod and Bar Mills, Detection, Classification, and Elimination of Rod and Bar Surface Defects
Seams are longitudinal voids opening radially from the bar section in a very straight line without the presence of deformed material adjacent.
Seams may be present in the billet due to non-metallic inclusions, cracking, tears, subsurface cracking or porosity. During continuous casting loss of mold level control can promote a host of out of control conditions which can reseal while in the mold but leave a weakened surface. Seam frequency is higher in resulfurized steels compared to non-resulfurized grades. Seams are generally less frequent in fully deoxidized steels.
Seams are the most common bar defects encountered. Using a file until the seam indication disappears and measuring with a micrometer is how to determine the seam depth.(Sketch from my 1986 lab notebook)
Seams can be detected visually by eye, and magnaglo methods; electronic means involving eddy current (mag testing or rotobar) can find seams both visible and not visible to the naked eye. Magnaflux methods are generally reserved for billet and bloom inspection.
Seams are straight and can vary in length- often the length of several bars- due to elongation of the product (and the initiating imperfection!) during rolling. Bending a bar can reveal the presence of surface defects like seams.
An upset test (compressing a short piece of the steel to expand its diameter) will split longitudinally where a seam is present.
Seams are most frequently confused with scratches which we will describe in a future post.
“These long, straight, tight, linear defects are the result of gasses or bubbles formed when the steel solidified. Rolling causes these to lengthen as the steel is lengthened. Seams are dark, closed, but not welded”- my 1986 Junior Metallurgist definition taken from my lab notebook. We’ve a bit more sophisticated view of the causes now.
The frequency of seams appearing can help to define the cause. Randomly within a rolling, seams are likely due to incoming billets. A definite pattern to the seams indicates that the seams were likely mill induced- as a result of wrinkling associated with the section geometry. However a pattern related to repetitious conditioning could also testify to billet and conditioning causation- failure to remove the original defect, or associated with a repetitive grinding injury or artifact during conditioning.
My rule of thumb was that if it was straight, longitudinal, and when filed showed up dark against the brighter base metal it was a seam.
Rejection criteria are subject to negotiation with your supplier, as are detection limits for various inspection methods, but remember that since seams can occur anywhere on a rolled product, stock removal allowance is applied on a per side basis.
If you absolutely must be seam free, you should order turned and polished or cold drawn, turned and polished material. The stock removal assures that the seamy outer material has been removed.
Metallurgical note: seams can be a result of propogation of cracks formed when the metal soidifies, changes phase or is hot worked. Billet caused seams generally exhibit more pronounced decarburization.
If you are a savvy shop, you are working on this issue today- if the average age of our manufacturing workers is 50, that means over half of our workforce are within a few short years of retirement.
