Category: Corrosion Resistance
2 thoughts on “Corrosion Resistance”
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H2 Steel – H1 the sequel
Background
A recent Spyderco Byte has announced a replacement for H1 steel – H2. H1 is known for being a very high corrosion resistance steel used primarily in Spyderco’s Salt line of knives. I have a previous article about the design of H1 and how it “works” which you can read here. I am somewhat tempted to re-write large chunks of that article here because H1 is one of the most misunderstood knife steels but I am going to try to hit a few of the highlights without much explanation and I hope you will read the earlier article to understand what I am referring to:
Knife Steels Rated by a Metallurgist – Toughness, Edge Retention, and Corrosion Resistance
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LC200N/Cronidur 30 – History and Properties
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New T-Shirts!
After requests from any kind fans we now have t-shirts available, including an awesome one with the MagnaCut logo on front and knife grinding man on the back. Note it is available in a few different styles and colors. Click this link if you want one.
CPM-S110V Steel – History and Properties
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I’m eventually going to stop plugging my book Knife Engineering in every new article, but that day is not today. Go buy one for yourself, and everyone you know, as a Christmas present.
M398 Steel Testing – Edge Retention, Toughness, and More
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The steel ratings table from my new book Knife Engineering has now been added as a Patreon-exclusive with M398 added to the table.
What is the Future of Stainless Knife Steel Design?
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I completed a minor revision to my new book Knife Engineering to correct a few typos. Some readers outside the USA also asked for more conversions from Fahrenheit than were present originally, so I incorporated both Celsius and Fahrenheit everywhere in the book in the text and tables, though some images and charts still have only one temperature scale or the other. I wouldn’t say that the changes in the revision are big enough to buy a new one if you have it already, this is not a new edition, but if you haven’t purchased one yet this is as good a time as any.
ZDP-189 and Cowry-X – Super Steel or Overrated?
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ZDP-189 and Cowry-X
ZDP-189 is a steel produced by Hitachi and Cowry-X is produced by Daido. I have not been able to find much background information on the development of these steels. Sal Glesser of Spyderco reported he first heard about ZDP-189 around the year 2000 [1], and the earliest reference I have found to Cowry-X on Bladeforums in 2001 [2]. So both of the steels have been around for some time. The fact that two companies released essentially the same product perhaps indicates that the steel was not patented, which means little information would be available about its development. Both steels have an interesting composition with 3% carbon and 20% chromium along with a few other small additions. There are a few different reported compositions for ZDP-189 in terms of the Mo, V, and W content but below is from Spyderco.
Crucible S45VN Steel – Everything You Need to Know
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Thanks to Niagara Specialty Metals for getting me a bar of S45VN for the experiments necessary for this article.
Corrosion Resistance Testing of Stainless Knife Steels
No new Patreon supporters this week! I think this is the first article where I didn’t have any new people to thank at the top. Thanks to all my current Knife Steel Nerds Patreon supporters.
Corrosion Resistance of Steel
How to Design Knives that Do Not Fail
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Failure Modes
A common engineering technique is to evaluate designs based on how they failed, or may fail. Failure modes are identified and the designs are modified to prevent those failures. These ideas are simple in concept but it is surprising how easy it can be to miss the forest for the trees. In terms of predicting failure modes in some cases it is easy and in some it is difficult. You would expect a large chopping knife to require heavier edge geometry to prevent chipping and rolling, or a seawater diving knife to require high rust resistance. Other times failure modes are identified through testing of the knife or by returns from customers. Whatever the source of the failure, there are usually relatively simple methods for fixing each one, though the trade-offs for doing so may not be desirable.
This was really informative article, As corrosion is a big problem for steel and other metal but resistance can control this problem. Thank you for sharing this.
Larrin,
Has anyone ever attempted to mostly use Molybdenum, or Moly/Nitrogen, as the leading corrosion resistant element in a steel to eliminate or mitigate chromium in a steel? I need to double check the corrosion resistance formula you created, but I was curious if it is possible for an all Moly “440”.
Maybe a Niobium/Moly homunculus is possible.