Working Mangalloy

Date 07-31-2004 10:20

This alloy is new to me as well, but if you can tell us the chemical composition of the alloy, we may be able to discuss further on this thread.

By Brainfarth (*)

Date 08-01-2004 23:39

Here is all I could find on the net: "Mangalloy Steel Plate is an 11-14% manganese steel that performs best in extreme impact applications. Under shock and impact it nearly triples its initial surface hardness, retains its interior toughness and acquires a high polish. These features, combined with Mangalloy's high tensile strength, make it an ideal material for heavy impact and abrasive service. Mangalloy steel is also non-magnetic."
That's all I know about the stuff other than they use it in some bike parts.

By billvanderhoof (****)

Date 08-02-2004 03:40

http://www.steelforge.com/infoservices/properties/step2.asp?Family=Carbon+Steels
If you go here and set the box at the upper right to mangalloy the site claims it will give you properties of this material. You will have to register (I didn't). It seems that this material is a member of the class AR400 if that is any help. http://www.fordsteel.com/mang_plates_bars.htm
This seems to be the manufacturer or perhaps distributor of this material. I doubt that you can work this stuff cold and it may have rather precise requirements for hot working if you want to retain its properties. The manufacturer will know, usually the maker will cooperate with you. There is some how to contact us stuff at that address.

Good luck
Bill

By Brainfarth (*)

Date 08-02-2004 04:54

Thanks for those links. Steelforge.com has some good information on the subject. I think I've got an idea on how I'm going to work it. Thanks again.
-Mike

By ajoy

Date 08-02-2004 05:13

Thanks for the information. Now it is clear to me as to what is it. this steel is the same as Hadfield steel or austenitic manganese steel. I have worked on this steel once a couple of years back.

I can tell you some important rules for welding this steel :

1. the most popular welding electrode to weld this steel is 18Cr-8Ni-5Mn type stainless steel electrode. this may be available in various brand names, I remember citochromax-N from Oerlikon.

2. After casting, it is heat treated ( water quenched from 1050 deg.c) to reduce its hardness to 240 BHN. It picks up hardness during prolonged welding or impact by precipitation of manganese carbide. Thus the welding always needs to be done in the softened state. Do not weld if it is already work hardened.

3. Keep the interpass temperature as low as possible ( 120 deg. c. max) otherwise the hardess will increase. try to cool the job as fast as possible. do not allow heat to build up at one place. do intermittant welding to evenly distribute the heat. if the job is big, give the job some forced cooling to dissipate the heat on a continuous basis.

as the material is austenitic, there is no chance of cold cracks. But hot cracks can occure if the above not followed.

Make the first piece and then do penetrant test before continuing.