When machining carbon and alloy steels, Crater Wear is the normal tool failure mode. Overheating is an unpredictable failure mode. It can be one of two failure modes, Thermal Checking ( or Cracking- my first boss called it “Crazing” ) or Deformation. Usually, when an irate customer ran into overheating issues, the tool they sent back to me had deformed to the point that it looked like it had been made out of lava.
The lack of predictability of failure by overheating creates issues for the shop beyond the obvious. Parts produced immediately prior to failure are suspect and must be validated prior to release, to avoid sending rejectable product to customers. Overheating can thus be a “delivery problem” in your customer’s eyes.
Here are 5 tips to get out of Overheating Tool Failure Mode and back to normal predictable Crater Wear Tool Failure Mode when machining steel:
Improve lubrication coolant delivery or formulation. Sometimes adding an extra coolant line to the position will eliminate the problem. Confirming your coolant is up to spec should be done before electing to buy a new “super duper formulation.” First things first!
Use a harder grade of carbide with more Ti (Titanium)
Increase the Feed Rate (IPR) inches per rev
Reduce the Speed (SFM)
Consider Ceramic or Cermet Tooling. Note- these are not really appropriate for low carbon (less than 0.20% C) steels. Low carbon steels become gummy and stringy at speeds typically used for ceramic tools.
These tips will address your overheating problem by reducing the friction, surface adhesion, and improving removal of heat, (improved coolant, delivery); improving the tool’s ability to withstand cutting conditions, and reducing the heat inputs by decreasing speed and increasing feed.
For more great information on this subject look at this lesson from Fox Valley Technical College.
The WTO just handed China a 460 page ruling regarding how the country handles American books, movies, and music. Here is a 9-page .pdf of the conclusions and findings. Dispute DS363 (here’s a summary) has at its core how the Chinese distribute and ‘protect’ from piracy American creative works in that country. So why should precision machine products manufacturers care about how the Chinese “distribute Hollywood movies, books, and music?”
“Sometimes the law defends plunder and participates in it. Sometimes the law places the whole apparatus of judges, police, prisons and gendarmes at the service of the plunderers, and treats the victim – when he defends himself – as a criminal.”- John Frederick Bastiat
Reason 1: Intellectual property rights are at the root of every bit of legitimate commerce. It isn’t just Hollywood movies being pirated across the pacific. Industrial designs, machined parts, counterfeit products are legion from the country whose premier, Hu Jintao, Mr. Obama will soon host.
Reason 2: This is the portent of the authentic test of President Obama: his dealings with Hu Jintao next month at the G 20 Summit in Pittsburgh Sept 24-25, 2009. Will he execute the appropriate remedial actions against the Chinese violations recognized and confirmed by due process via the WTO, and ITC, protecting American jobs and interests?
Before that Pittsburgh meeting, the administration must rule on a recommendation by the US International Trade Commission to impose up to a 55% tariff on Chinese Tires. We’ve been following the Cheap Chinese Tires deaths cases since our ethics class at Walsh University in July of 2007. These issues have been around for a long time… the current cheap tire row is a suit filed by the USW who charged that the flood of cheap Chinese tires had resulted in massive loss of jobs.
Is Obama as wise as Solomon? Will he stand up for American interests? How will he, as one of the world’s leading debtor executives- respond to his legal responsibilities to enforce the trade laws with China, perhaps his largest creditor?
Will he deliver the remedy won by the USW against Chinese dumping, in light of his need for cooperation from China, a leading purchaser of US Treasuries? Or will he acquiesce, complicit in the plunder of American intellectual property rights and jobs?
After 8 years of nonfeasance on the China Currency Issue out of Washington D.C., we’re wondering. Could this be a Change? “The worst thing that can happen to a good cause is, not to be skillfully attacked, but to be ineptly defended.” John Frederic Bastiat
Watch these China cases for a glimpse of our industry’s future. And an understanding of what the current administration thinks of manufacturing.