finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
topic 4990

Basic annealing of 4130 question


A discussion started in 2000 & continuing through 2017 . . .

(2000)

Q. I need to Parkerize some parts that I have welded on (mig) and after parkerizing, the welds show as very dark in color compared to the rest of the surface.

I have been told that if I anneal them, it will not show. How is this done? The metal is 4130 tubing and there are spot/fill welds. Please be specific and technical. Any info will be helpful. Thanks, Mike

Mike Klos
- Wentzville, Missouri


(2000)

A. The surface appearance after surface treatment is affected by the chemical composition and/or microstructure of the substrate. The weld will certainly have a different structure than the alloy steel and probably a different composition. Annealing to homogenize the microstructure would involve heating the entire part to a temperature of about 1600 °F, then furnace cooling. This heat treatment may not change the final surface appearance if the weld metal has a different composition than the base metal.

Also remember that the heat treatment will change the mechanical properties of the alloy steel. A better alternative may be to duplicate the original heat treatment - probably either normalized or quenched and tempered.

larry hanke
Larry Hanke
materials testing laboratory
Minneapolis, Minnesota




Does stripping powder coating at 800 °F weaken 4130 steel?

July 20, 2016

Q. I am using 4130 normalized on a recent project. In some cases my powder coater has to repaint due to coverage or other issues. He puts the powder coated parts in an oven at 800 °F to strip the old powder. Does the 800 °F "tempering" reduce the ultimate strength of 4130?

JOHN MCGHEE
product designer - Parkdale Oregon USA


September 20, 2016

A. It would depend on the hardness requirement of the final product and the final tempering temperature. Normally one wants to stay around 50 °F below the final tempering temperature to avoid any affect to the final hardness.

Donna Warner
- New Century Kansas USA



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.