Roll Cage Material

[OutCell]

Hello,



Well i am trying to conduct an FEA on roll cages. I found that the usual materials used for Roll cages (According to FIA regulations+not) were:



1) CDS Carbon Steel



2) ERW Mild Steel



3) DOM Mild Steel



4) Cr (Chrome Molybdenum) Steel



Now i was searching for more info on the specific properties and specs on these but i could only find AISI 1018 steel which i think is CDS?



Anyone knows the specific material+properties used or more information for these 4 that is used in Roll Cage making?


I tried looking on MatWeb, but the results are all general and got me confused a little. Please help me out



thanks

[OutCell]

Hello,



Well i am trying to conduct an FEA on roll cages. I found that the usual materials used for Roll cages (According to FIA regulations+not) were:



1) CDS Carbon Steel



2) ERW Mild Steel



3) DOM Mild Steel



4) Cr (Chrome Molybdenum) Steel



Now i was searching for more info on the specific properties and specs on these but i could only find AISI 1018 steel which i think is CDS?



Anyone knows the specific material+properties used or more information for these 4 that is used in Roll Cage making?


I tried looking on MatWeb, but the results are all general and got me confused a little. Please help me out



thanks

[Michael Royce]

It seems as though when it comes to roll cage materials (and basic steel tubing) a number of people confuse the manufacturing processes and the actual materials.

ERW, DOM and CDS are different processes of manufacturing the tubing. Mild steel, alloy steel, 1020, 4130, T45, Chromoly, etc. all refer to the type of steel, the material from which the tubing is made.

Here are some basics.

Manufacturing Processes
− Tubing is a pipe or hollow cylinder. The terms "pipe"� and "tubing"� are almost interchangeable, although "tubing"� implies tighter engineering requirements than "pipe"�. Both "pipe"� and "tubing"� imply a level of rigidity and permanence, whereas a "hose"� is usually portable and flexible.
− ERW – is Electrical Resistance Welded tubing. Flat stock is formed into a tube and them resistance welded along the joint.
− DOM – is Drawn-Over-Mandrel tubing. DOM tubing does not have to be seamless. It is usually made from electrical-resistance-welded (ERW) tube that is cold drawn through a die and over a mandrel to create such characteristics as dependable weld integrity, dimensional accuracy and excellent surface finish.
− CDS – is Cold Drawn Seamless tubing. Seamless tubing is produced by extrusion. The steel, in the form of a billet, is pushed and/or drawn through a die of the desired shape.

Types of Steels
There are many, many different types of steels. But for Formula SAE we usually deal with two types, "mild"� steel and "low alloy"� steel.
− "Mild"� steel is classed as a "low carbon"� steel, with typically less than 0.3% carbon by weight. It typically contains a little (0.1-0.5%) silicon (Si) and a little (0.3-0.9%) manganese (Mn) as well.
− It seems as though every country has its own alphanumeric designations for steels. In the USA we use the 4 digit American Iron and Steel Institute (AISI) or SAE designations, such as SAE 1020 (or AISI 1020) and SAE 4130.
− 10xx denotes a plain carbon steel with less than 1.0% manganese.
− SAE 1020 (AISI 1020) is a non-corrosion resisting, plain carbon, "mild"� steel, with 0.18-0.23% carbon, 0.15-0.30% silicon and 0.30-0.60% manganese by weight.
− 41xx denotes a Chromium-Molybdenum alloy steel.
− SAE 4130 (AISI 4130) is a non-corrosion resisting, "low alloy steel"�, containing 0.28-0.33% carbon, 0.15-0.35% silicon, 0.8-1.1% chromium (Cr), 0.4-0.6% manganese and 0.15-0.25% molybdenum (Mo) by weight. It is often referred to as "Chromoly"�.
− T45 is a UK, Carbon-Manganese, "aircraft"� alloy, containing 0.17-0.25% carbon, 0.10-0.35% silicon, 1.30-1.70% manganese, 0.25% max. chromium, 0.40% max. nickel and 0.10% molybdenum by weight.

As far as mechanical properties are concerned, it all depends! Not only do they depend on the type of steel that is used, but they also depend on other factors such as the heat treatment, and whether the material has been "cold worked"�. I am not a metallurgist, but one has to think, for instance, that DOM tubing has higher tensile strength than ERW tubing of the same material, as the former has been cold worked by going through the DOM process.