Normalizing procedure for steel heat treatment

[mariovalenti]

I have a set of SA106 steel pipe, which I want to normalize (heat treatment) to improve its properties to reach the minimum values of impact test (Charpy V notched) at -42ºC (-43.6ºF).
I can't get SA333 pipes, so my unique option is to do a normalizing and try to pass the impact test.
The pipes are: 2" XXS, 3" XXS and 6" SCH120.
Can anybode suggest a curve temperature-time to do the normalizing heat treatment (we have equipment for this)?
Would be better to do a 'double' normalizing heat treatment to increase possibilities to pass the impact test?.

Thank you in advance.
Mario

 

[metengr]

mariovalenti;
I would try the following using coupons for the normalizing heat treatment followed by impact testing;

1. Heat to 1600-1650 deg F and hold for 1 hr/inch of material thickness.

2. Air cool with air movers.

3. Impact test

4. Repeat steps 1 and 2 above for the second coupon.

By the way, what is your minimum CVN value?

 

[mariovalenti]

The average Cv value is 20J (15 ft-lb)for 10x10 mm specimen.
Thank you very much for your help.
Mario

 

[stanweld]

You may not be able to achieve your results. Advise checking the grain size and chemistry. If Al content is above .016% (peferably .020%) fine grain melting practice was employed and your chances will be greater of meeting the requirements. Also check check the sulfur content and carbon & manganese contents. Low carbon and higher Mn contents will also help.

I would also recommend both the single normalizing treatment proposed by metengr and a double normalize treatment on sample coupons.

Good Luck

 

[mariovalenti]

Thanks for your suggestion.