Minimum temperature range for common low carbon steels
Minimum temperature range for common low carbon steels
(OP)
Can anyone steer me in the right direction for determining what would be minimum recommended temperature range for common low carbon steel?
For instance, what would be the recommended minimum temperature that one should use ASTM A500-Grade B tubing in?
I am somewhat familiar with the Charpy Impact tests etc. for determining impact toughness, and we have needed to use this for projects with low temperature requirements. But I am having difficuly determining to what temperature range our product (without special material requirements)would be using our normal common materials.
Any help would be appreciated.
For instance, what would be the recommended minimum temperature that one should use ASTM A500-Grade B tubing in?
I am somewhat familiar with the Charpy Impact tests etc. for determining impact toughness, and we have needed to use this for projects with low temperature requirements. But I am having difficuly determining to what temperature range our product (without special material requirements)would be using our normal common materials.
Any help would be appreciated.





RE: Minimum temperature range for common low carbon steels
From what I have seen, the FATT (@50% flat fracture) for low carbon steels can range from 20 deg F down to -20 deg F. To be conservative in design, I would recommend 20 deg F due to variability in material composition and grain size.
You can purchase fine grained, low carbon steels for use in low temperature service that could take you to about -50 deg F .
RE: Minimum temperature range for common low carbon steels
RE: Minimum temperature range for common low carbon steels
ASTM A 36 - "Structural Steel", which covers carbon steel shapes, plates and bars. Order with the following supplemental requirements to assure improved notch toughness; S2 silicon killed, fine-grain practice and S5 Charpy impact test.
For plates only, a specification like ASTM A 516 - "Pressure Vessel Plates, Carbon Steel, for moderate and lower temperature Service". Order with supplementary requirement S5 Charpy impact test.
ASTM A 573 - "Structural Carbon Steel Plates of Improved Toughness". These steels are made to a fine-grain practice.
RE: Minimum temperature range for common low carbon steels
The standard carbon steel materials are usually divided into two groups wrt impact properties:
1. low temp steels
2. not so low temp steels
The ASTM requires for low temp steels better control of impurities, the steels are kileed, etc. And at the end of the day they are impact tested.
The "not so low temp steels" might not have all the bells and whistles specified but to make their life easier and probably it is cheaper in a long run, some of the mills make them to the same specification as low temp steels. The only difference is the "not so low temp steels" are not impact tested. This is true for piping, the structural steel might be different.
You may be able to use any carbon steel material provided the impact properties are confirmed by the test. Obviously what metengr says is true: the fine grain steels offer the best impact properties. I don't know how low the MDMT is going to be in your application.
Talk to your suppliers, they should be able to tell you what material they can guarantee and prove its properties. It might be worth your while to investigate this avenue.
RE: Minimum temperature range for common low carbon steels
RE: Minimum temperature range for common low carbon steels
To make the long story short: they are not certified for low temperature service. And there is no say how low is "low" because the Specification does not give the figure. You could possibly compare that material to one of those listed in ASME IIA to assess the impact properties from UCS-66 but there is always a risk of not comparing "apples with apples".
If you want to use ASTM A500 Gr. B in your low temp. application you need to impact test the materials/components anyway.
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RE: Minimum temperature range for common low carbon steels