Originally Posted by strajesh

Dear All,

We are discussing a project in Russia to build a portal reclaimer to install at Minus (-) 25 degree Celsius.

Can anyone please recommend the appropriate structural steel suitable for this application especially in IS or ASTM Standards??

Also what are the other areas to take care??

Your first point of contact should be you steel producers. They are the best source of such information.

Low temperatures can do strange things to mechanical properties. Not only will steel become more brittle, but you can see odd things happening to UTS and yield points.

In many cases, the steel producers will not give you a yield point, but a 0.2% proof stress (sometimes just called proof stress). This is because there is no significant yield point at these low temperatures. The 0.2% proof stress is the stress at which you will see a permanent 0.2% strain in the test sample when the load is removed. What this means is that you need to be careful when selecting the design limit state as there is no effective yield in the material. With such materials, the 0.2% proof stress is substituted for the yield stress, however you cannot use the limit state that you would normally use for material that had a yield point and so a point of plasticity.

Many years ago, I was Product Development Engineer with Dexion Australia. Our pallet racking was used in freezers, and in the main, we did not have to do anything as far as load capacity was concerned. One thing we did have to do was to halve the allowable beam deflection as with the standard deflection limit, the two part interlocking C section beams would open up and then when the load was removed, the beam sections would not return to their normal positions. Even when removed from the freezers and allowed to get to room temperature, they would not return to their normal positions. ■

You should include Charpy test results along with your material certificates. For -29 C it is mandatory in most countries and codes. For the steel itself you could rummage through Macready's orange book or any similar steel suppliers literature: as already recommended. Whatever you choose it will probably require compatability with locally available steel as well. Why can't the customer advise? Are you afraid to ask him? Takraf have built many machines in Russia so why not ask your own actual HQ? ■

Besides the steel the material properties are pretty important to know as well as the actual site. Will the -25C be the lowest?

Often going below -25C or -30C, which is not uncommon in Russia, you also need to consider the gearbox materials.

Alse it is generally recommended to review all structures with regards to ice and snow-build up.

In some cases also the thermal expansions should be considered.

Originally Posted by strajesh

Dear All,

We are discussing a project in Russia to build a portal reclaimer to install at Minus (-) 25 degree Celsius.

Can anyone please recommend the appropriate structural steel suitable for this application especially in IS or ASTM Standards??

Also what are the other areas to take care??

Best Regards,

S.T RAJESH

-------------------------

TAKRAF India Pvt. Ltd.,

94/3, TTK Road, Alwarpet,

Chennai - 600 018. INDIA.

Email: s.rajesh@takraf.com

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what I know the standard, there are ASTM A500 Cold Formed ,EN 10219 Cold formed ,JIS G 3466 , they are from others contries. ■