Low Temperature Structural Steels

[dakers]

Hello,

I am currently working on a project and I am having difficulty finding structural steel to be used on the job. The final location for the heater is in Siberia and the customer has asked that we use low temp carbon steel and that all steel be rated for -56degreesF. Currently we are purchasing structural shapes of A572 GR50 and having them heat treated and some of the steel is still failing our Charpy Impact Test requirements. We cannot afford to keep purchasing material and simply hoping that it passes. I have found other grades such as A203, A537, A533 that would seem to work fine but I cannot find a steel distributor in the U.S. that has structural shapes of these grades. I am currently looking into A588 as I was told it is very similar to A572 but has a better history of passing impact test and is readily available. If anyone could please offer any insight or alternative material it would be greatly appreciated. Thank you! - Dakers

 

[metengr]

Do you have a material purchasing specification that calls for a specific CVN impact value at minimum temperature as part of the purchase requirement? There should be no reason to simply purchase low temperature steel and have it heat treated, test it after purchase. This makes no sense. In your specification requirements for purchase, you can call out Supplementary Requirements, like CVN impact testing, tested at X temperature with a minimum CVN impact value of Y that must be met before purchase.

 

[gtaw]

You might consider selecting an ASTM A709 steel that has notch toughness properties you need. ASTM A709 steels are typically specified for bridge construction and many of them meet notch toughness requirements. Whether they will meet your requirements is something you will have to research.

Best regards - Al

 

[desertfox]

Hi

Not sure whether you can source European standards but there are some that will meet the temperature requirement, you don't mention the energy figure.

http://www.macsteel.co.za/files/en_10025_-_2004.pdf

 

[dakers]

metengr - Yes we are doing just that. Purchasing A572, sending it to be heat treated, and sending a sample of the heat treated material to a test facility to be impact tested. For example we call out 10" x 25# channel to be tested at -56F with three test specimens to meet an average of 15ft-lbs, with no one test below 10 ft-lbs, and no two tests below the average. The 10" channel failed to meet those requirements but 6" x 8.2# channel of the same material passed. According to our steel supplier, once the steel has been heat treated we have purchased it, pass or fail.

gtaw - I will look into the A709 to see if it meets our requirements.

desertfox - I don't see the problem with sourcing European standards, the customer did not specify against it. Please see one of our energy requirements above and let my know what you think. I will research it as well.

Thank you all and I apologize if I am vague or unclear in any way as it is my first post.

-Dakers

 

[desertfox]

Hi

see page 7 table 2, impact energy 27J=19.86 ft-lbs , spec S355 NL

 

[dakers]

gtaw - The A709 50W seems like it could work. Do you know if it is available in structural shapes such as C-channel, I-beam, and Square Tubing? Do you know of any suppliers in the U.S.?

Thank you! -Dakers

 

[dakers]

desertfox - there seemed to be several specs in that pdf that met our requirements so thank you! It seems that A633 is equivalent to S355 NL. Would you happen to know if S355 NL is available in structural shapes? I am only finding A633 steel plate.

Thanks again! -Dakers

 

[desertfox]

Hi

I think it might only be in plate form however look on this link

http://www.tatasteeleurope.com/en/p...onstruction/declarations-of-performance#54187

 

[weldstan]

As you have discovered, A-572 Gr 50 will not meet your toughness requirements. You will need to go to your mill suppliers and find out which materials specifications will meet the requirements and then address those requirements in your P.O.

 

[dakers]

weldstan - That's just the problem, none of our mill suppliers have ever had to deal with ambient temperatures being so low (-56F) requiring carbon steel so they haven't been able to offer any alternatives. Apparently they generally deal within the states where a temperature that low would almost never be dealt with and if they do see temperatures that low they turn to stainless. I spoke with a mill in Pennsylvania who offered that A588 might pass our requirements as it is a very similar steel to A572 with added chromium, nickel, and copper. I think we are going to have a few heat runs of this material tested to see if it handles the low temp any better than A572.

Thank you! -Dakers

 

[weldstan]

Your best bet is A-709 HPS 50W.

 

[dakers]

weldstan - Do you know if A-709 HPS 50W is available in structural and could you recommend a supplier?

Thank you! -Dakers

 

[weldstan]

It is available in shapes. Google ASTM A-709 and I'm sure that you will find a manufacturer. Because it is seldom used in the USA, you may find it difficult to find a warehouse supplier.

 

[TVP]

Central Steel & Wire stocks structural shapes in ASTM A709 Grade 50. I'm sure there are others. With regards to tubular products, you should probably investigate suppliers that certify to ASTM A1085 with specified low temperature properties. Atlas Tube is one such supplier.

http://www.centralsteel.com/index.php?option=com_content&view=article&id=55&Itemid=116

http://www.atlastube.com/astm-a1085

 

[dakers]

Hi all, just wanted to follow up and share our results. We had A588 and A709 structural shapes tested at -56F.

The A709 was untreated as their metallurgist said heat treating this particular grade would not help our cause but in the end it failed to meet our requirements of 15ft-lbs.

The A588 was normalized at 1700F for approximately 20 minutes before the charpy testing at -56F. These samples performed excellently showing averages of 45ft-lbs up to 142ft-lbs on some of the heavier shapes.

Again, just wanted to share our results in case anyone comes across something like this in the future. Thank you again for all your help and suggestions!

-Dakers