Rusting Analysis of Carbon Steel

[tr3yanderson]

I recently was reading through a post where someone was discussing how fast or slow different tool steels rust. Though, I haven't seen good a comparison across many steel types. I know the basics such as the more Chromium the better resistance. but I'd like to see some actual testing done. I'm wanting to do some detailed testing.

Here's my thought since I don't have the means right now to buy 10+ different steels, I know all of these steels are used by many of you guys here and if you have a piece of scrap say like a 1 inch or 2 inch square piece or what not. I'd like you to send me a piece. (I can pay postage). I'll set up a nice little testing scenario with all our samples and should get some really good data. If you all decide not to, no worries I'll eventually get around to buying different steels and will do it down the road. If you all are game, here is the list of steels I'm wanting to test, message me and I'll send an address to send the scrap piece to. 1075, 1080, 1084 (I have), 1095, 15N20, 5160, 51200, 80CRV2, A2, D2, L6, M2, S2, S7, W1, W2, O1.

I've got some ideas on different tests. but what are ideas you all have or want to see. One issue I may not be able to test is heat treat consistency and how the heat treat may or may not affect how the steel rusts. What are your thoughts?

Thanks,

 

[kuraki]

How they're heat treated will effect the results. How they're finished will effect the results (surface finish). How you measure corrosion will effect the results (some are more prone to surface oxidation and some more prone to pitting).

My thoughts are, everyone knows everything in your list oxidizes quickly without surface treatment or RP of some kind with almost no resistance except for A2, M2 and D2 (in that order) and don't see a lot of value in a test.

 

[DevinT]

Just look at the amount of chrome and nickel in each alloy. You wil have increasing corosion resistance with increasing amounts of those alloys.

Hoss

 

[Natlek]

How can someone HT M2 steel in Paragon oven is beyond me ..........

Preheating: To minimize distortion and stresses in large or complex tools use a double preheat. Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1100°F (593°C) equalize, then heat to 1450-1550°F (788-843°C). For normal tools, use only the second temperature range as a single preheating treatment.

Austenitizing (High Heat): Heat rapidly from the preheat.
For Cutting Tools:
Furnace: 2200-2250°F (1204-1232°C)
Salt: 2175-2225°F (1191-1218°C)
To maximize toughness, use the lowest temperature.
To maximize hot hardness, use the highest temperature.
For punches, dies, and tools that require maximum
toughness without hot hardness:
Furnace: 2075-2175°F (1175-1191°C)
Salt: 2050-2150°F (1121-1177°C)

Quenching: Pressurized gas, warm oil, or salt. For pressurized gas, a rapid quench rate to below 1000°F (538°C) is critical to obtain the desired properties. For oil, quench until black, about 900°F (482°C), then cool in still air to 150 -125°F (66-51°C). For salt maintained at 1000-1100°F (538-593°C), equalize, then cool in still air to 150 -125°F (66-51°C).

Tempering: Temper immediately after quenching. Typical tempering range is 1025-1050°F (552-566°C). Hold at temperature for 2 hours, then air cool to ambient temperature. Double tempering is required. For large cross sections, and especially for blanks from which tools will be cut by wire EDM, triple tempering is strongly recommended.

 

[DevinT]

I thought this thread was about rusting.

Hoss

 

[Natlek]

I thought this thread was about rusting.

Hoss

Sorry , perhaps I misread this post . I thought that he intend to do HT on all this steel
.

I've got some ideas on different tests. but what are ideas you all have or want to see. One issue I may not be able to test is heat treat consistency and how the heat treat may or may not affect how the steel rusts. What are your thoughts?
Thanks,

 

[tr3yanderson]

Just look at the amount of chrome and nickel in each alloy. You wil have increasing corosion resistance with increasing amounts of those alloys.

Hoss

This is true, and I do understand the relationship here. I guess I'm just a visual person; I like to see the actual outcome of what the numbers are telling me. Thanks,

 

[DevinT]

If you quench from the higher end of the aus range, the more chrome is in solution and the higher the corrosion resistance, that is, for steels with chrome.

Some steels are designed for corrosion resistance, the rest are not.

Hoss

 

[DevinT]

This is true, and I do understand the relationship here. I guess I'm just a visual person; I like to see the actual outcome of what the numbers are telling me. Thanks,

Please do your tests and update us with the results.

Hoss