C-1008 Carbon Steel - Hardened?

[jchumley]

I work for a manufacturer who builds low pressure (non-ASME) welded plate heat exchangers for gas-to-gas applications.

We have a customer who has an abrasive application that we've been selling heat exchangers to for years. Somewhere along the way, a decision was made to change to C-1008 carbon steel, which I have always been told is a harder steel.

The customer recently asked for an option to change to a tubular heat exchanger, so we submitted an RFQ to the tubing vendor, who replied that C-1008 is a generic name and doesn't mean anything since once the steel is formed, it no longer has the same attributes.

I'm very confused since we were under the impression that the C-1008 was a harder steel, but it sounds like, according to the tubing vendor, that this isn't necessarily the case.

I should add that I'm not up to the ASTM/AISI codes and such, but we typically use a standard hot rolled steel for most of our work. Does A36 sound right?

Any help you can give me on this C-1008 thing would be helpful. Specifically, whether we've been fooling ourselves and what we'd want to use in welded tubing.

Thanks.

 

[EdStainless]

First you need to buy a copy of the spec that you are buying to. Then you need to look at the other grades within that spec.
I would offer more detail but I don't have my spec books available right now.

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[metengr]

Normally, for tubular heat exchangers, carbon steel tubing would be supplied as ASME SA 179 (or for non-ASME ASTM A179), which is a seamless carbon steel tube.

http://www.astm.org/cgi-bin/SoftCart.exe/index.shtml?L+mystore+gyhm8818

 

[jchumley]

Just as a clarification, further follow-up, the tubing vendor called me back and said that she was referring to A-1008 not C-1008. Can someone shed some light on the difference?

Also, we're not manufacturing pressure vessels and 99% of the tubing we buy is welded tubing, not seamless tubing.

The C-1008 is what we've been buying for sheet steel (11Ga - .120in thick), but we aren't real sure now what we've been buying.

 

[metengr]

The difference can be found by accessing the web site link I provided to you above. You should be using ASTM Standard Specification for your material purchases, and buy these standards for your purchasing folks. They are less than $50 USD per specification.

Now I see why your all over the map with regards to purchasing material for this heat exchanger. I would still consider seamless tubing A 179.

http://www.astm.org/cgi-bin/SoftCart.exe/index.shtml?L+mystore+gyhm8818

ASTM A1008/A1008M-07 Standard Specification for Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, Solution Hardened, and Bake Hardenable

 

[metengr]

jchumley;
Using the ASTM web site I performed a quick search of welded carbon steel tubing for you to consider. Here you go;

Title of Specification ASTM Designation


Seamless Cold-Drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes A 179/A 179M

Seamless Cold-Drawn Intermediate Alloy-Steel Heat-Exchanger and Condenser Tubes A 199/A 199M

Electric-Resistance-Welded Carbon Steel Heat-Exchanger and Condenser Tubes A 214/A 214M

 

[jchumley]

Okay, so I now know a lot more and hopefully I can clear up some of the confusion.

First, we were not using ASTM specs.

The C1008 spec was an SAE/AISI spec. My understanding is that SAE and AISI share the # designation

It turns out that when I went back through the old jobs that we were building the units out of C-1020 (which I found is an SAE spec). The reference I found said this is a high carbon cold rolled carbon steel. That would seem correct for an abrasive application, since the hardness would be higher.

Somewhere along the way, we had a problem getting the C1020 and the customer said it was okay to use C1008. Now what I can't find out is what's special about C1008. It seems to me that C1008 is just cold rolled carbon steel.

The information I found on efunda.com for both materials is as follows:

SAE/AISI C1020
Category Steel
Class Carbon steel
Type Standard
Designations
France: AFNOR CC 20
Germany: DIN 1.0402
Italy: UNI C 20
Sweden: SS 1450
United Kingdom: B.S. 040 A 20 , B.S. 070 M 20
United States: AMS 5032 , AMS 5032B , AMS 5045 , AMS 5045C , ASTM A108 , ASTM A29 , ASTM A510 , ASTM A519 , ASTM A544 , ASTM A575 , ASTM A576 , ASTM A659 , MIL SPEC MIL-S-11310 (CS1020) , SAE J403 , SAE J412 , SAE J414 , UNS G10200

Element Weight %
C 0.18-0.23
Mn 0.30-0.60
P 0.04 (max)
S 0.05 (max)

SAE/AISI C1008
Category Steel
Class Carbon steel
Type Standard
Designations
Germany: DIN 1.0204
Italy: UNI CB 10 FU
United States: AMS 5040F , AMS 5042F , AMS 5044D , AMS 5047A , AMS 5050F , AMS 5053C , ASTM A108 , ASTM A29 , ASTM A510 , ASTM A519 , ASTM A545 , ASTM A549 , ASTM A575 , ASTM A576 , FED QQ-S-637 (C1008) , FED QQ-S-698 (C1008) , MIL SPEC MIL-S-11310 (CS1008) , SAE J403 , SAE J412 , SAE J414 , UNS G10080

Element Weight %
C 0.10 (max)
Mn 0.30-0.50
P 0.04 (max)
S 0.05 (max)

According to this, the major difference is the carbon content, since both are cold rolled.

Am I right to believe that C-1020 is superior to C-1008 in terms of hardness?

Am I right to believe that if we want to find the tubing spec that we just pick whichever ASTM spec would apply for welded tubing under the above C-1020 designation?

Thanks for your help. I've learned a lot.

 

[stanweld]

AISI 1008 sheet is hardenable by cold rolling. It could be purchased with varying hardness levels depending on how much cold work is done or the temperature used for process annealing and subsequent temper pass cold rolling - % cold work. If you are purchasing hot rolled strip, the strength/hardness of 1008 will be substantially lower than for 1020. Ultimate tensile strength of hot rolled 1008 is generally < 40 ksi. Ultimate tensile strength of 1020 hot rolled strip will generally be > 60 ksi.

 

[metengr]

jchumley;

Am I right to believe that if we want to find the tubing spec that we just pick whichever ASTM spec would apply for welded tubing under the above C-1020 designation?

No, it is not that easy. I am not sure that you are even using the correct material for this application. Can you provide specifics regarding your stated abrasive application? Is this some type of flue gas that contains particulate? What is the gas temperature?

Simply specifying higher strength carbon steel may not be the best approach. Can you come back with more information?