Steel 101

Steel 101
Butler CC - 04/16/2010
By: Jason Gulick

In the autobody industry there are many types of steel. They range from the most formable grades with a low yield strength of 140 N/mm to ultra high strength steel with a strength of 2500 N/mm.

Some grades have special processing for a specific use, such as super-clean steels used in fuel injection systems, forging grades such as a camshaft and connecting rods. A key requirement for sheet steel intended for use in automotive pressings is that it is formable, so that it can be stretched without undue thinning in a press to form complex shapes. Softer grades of steel, having low yield strength, tend to be highly formable but lack the strength needed for the main loadbearing members of a vehicle. Higher-strength steel parts may be more difficult to form, since they do not stretch so easy, but it is better for the economy for weight reduction.

Ultra High Strength steel is used specially for safety critical areas on the vehicle such as the passenger compartment to ensure the safety of the passenger in a crash. It varies between 900 and 1200 N/mm. High Strength Steels, with a good balance of strength, formability, energy absorbtion, and durability, is used for a lot of the support in the body. HSS acts as support beams in the body and is normally between 600 to 800 N/mm. Steels that vary between 100 and 300 is normally the skin of your vehicle. The body is made with these steels.

Boron is the strongest steel currently being manufactured in the autobody industry, followed by Martensitic. Boron is not easily formed or forged. It is mainly in the passengers area of the vehicle. It not that common to find this steel yet due to its recent discovery, but it is now on the manufacturing line and in the new 2010 Chevrolet Camaro. Martensitic varies in strength from 650 N/mm to 1200 N/mm, and is also very difficult to forge or mold.

Steel manufacturers can use a range of techniques to make higher-performance steels. These techniques include grain refinement, work hardening, precipitation hardening and heat treatment. Grain refinement is a method of strengthening materials by changing their average crystallite (grain) size. Work hardening, also known as strain hardening, is the strengthening of a metal by plastic deformation. This strengthening occurs because of dislocation movements within the crystal structure of the material.

Any material with a reasonably high melting point can be straightened in this fashion. Precipitation hardening, also known as age hardening, is a heat treatment technique used to increase the yield strength of malleable materials. Heat treatment is to treat metal by alternate heating and cooling in order to produce desired quality.

Going Green - Shops and Schools Transistioning To Waterborne Paint

Going Green has been the topic at Butler Community College as we are in the process of switching to PPG's Waterborne Paint System. 

This week's featured shop on I Saw It On Google also talks about waterborne paint as they are interviewed.  Be sure to watch the video as they educate us about their experience of switching to waterborne.


Butler also hosted a waterborne paint class Friday 4/9/10 for other schools to learn more about waterborne paint and going green. At the training event we had Steve Johnson, PPG Representative, attend and help with questionsin the classroom.  Steve also demonstrated how to use the waterborne paint in the lab. The instructors from the other schools were impressed with the fact that the waterborne paint does not need to have a mixing bank, the fast 2-4 minute flash time to sand, tape for tow-tone, or clear that the paint offers.   The other schools are considering making the switch as well.  

There are many impressive benefits the waterborne paint has to offer, but the biggest benefit is that we will be helping our environment by allowing less VOC's to escape into the environment. This will create a safer working environment for our students and everyone else as well.


This is just the start of our transition of switching to waterborne, but we plan to be ready for the start of Fall 2010 classes in August. I will keep you posted on every step of the way so check back to learn more about waterborne paint. 

Have you already made the switch?  We would love to hear your stories about water borne paint as well.  Leave us a comment with you advise, concerns, or comments.

3M Dynamic Mixing System Review - Finishing Glaze

Mixing and Waste
I recently used the finishing glaze that 3M has for their new Dynamic Mixing System and was well pleased. The product mixed instantly as it exited the tip. I purged the glaze, but all product fully hardened on the paper towel. I concluded that a technician could use this product with minimal waste. The product mixes instantly, which will require minimal purging and you can apply only the amount of glaze you need to the surface that you are working on. Therefore, I found the mixing capabilities to be excellent and wasted product to be minimal.

Spreading
The glaze was easy to spread and produced a pinhole free layer of glaze.

Drying
The 3M glaze tended to heat up faster and dry quicker than other glazes that I have used. Works great and will increase repair time. However, do not try to over work the glaze. Apply the glaze with a tight coat followed with looser pass while leveling the glaze. If you move too slow or try to over work the glaze, it will start to harden and cause problems

Sanding
After allowed the glaze to fully dry I knocked the highs lightly with 80 grit sandpaper. Then I guide coated the glaze and finished it out with 150 grit sandpaper. The glazed sanded easy and produce a defect free surface that was ready for primer.

Satisfaction
I am satisfied with the 3M finish Glaze and would recommend it to others. If you do not use the product daily or weekly, the cost of the application gun may not be worth your investment. Therefore, this is an excellent system for a body shop, but not for the DIY enthusiast that only uses fillers once or twice per year.

Is Your Body Repair or Automotive Shop Female Friendly?

Is your body repair or automotive shop female friendly? Here are a few helpful tips from Jody DeVere, the CEO of http://AskPatty.com