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> But the bigger problem is that stainless steel has significantly worse mechanical characteristics This is a common claim, but I’m not sure I really believe i

by amluto 1y ago

> But the bigger problem is that stainless steel has significantly worse mechanical characteristics This is a common claim, but I’m not sure I really believe it. Even for applications that require especially good mechanical characteristics, e.g. tool steels, good stainless alloys can be very good. I would believe that the stainless alloys that are widely available in large quantities at somewhat reasonable prices for structural use (e.g. 304 and 316 stainless steel) have mediocre mechanical properties.

cyberax 1y ago
??? Tool steels are not stainless, as anyone who forgot to stow away tools properly can confirm.
cyberax 1y ago
Ah, got it. You mean modern stainless steels are good enough even as tool steel replacements? It's indeed true, but at the same time, non-stainless steels are getting even better.
- amluto 1y ago
  I don’t have a good, accessible source for traditional tool applications, but knives are basically tools, and knifesteelnerds.con is a fantastic resource from an author who is a genuine expert: https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by-a-metallurgist-toughness-edge-retention-and-corrosion-resistance/ https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by... Compare the toughness vs hardness charts for non-stainless and stainless. You’ll find some low alloy non-stainless steels with excellent toughness at a given hardness level, but those have poor wear resistance. Other than that, the charts are just not very different. Note that even some of the very most wear-resistant steels are stainless (but you’ll have to recognize the names or look them up to tell). Of course, this says nothing about price, availability in large quantities, weldability, or ability to form them in the ways that people building large structures might want.
  - cyberax 1y ago
    Hardness is not really the weakest point of stainless steels, anybody who tried high-carbon knives and got disappointed with them can attest to it. Stainless steels have lower yield strength compared to carbon steels, meaning that the stainless steels bend under stress more easily. This is not an issue for knives, but it is a big issue for construction materials.
    - amluto 1y ago
      Steel hardness and yield strength are very strongly correlated: https://wpfiles.mines.edu/wp-content/uploads/aspprc/ResearchMaterials/Publications/386-Pavlina.pdf https://wpfiles.mines.edu/wp-content/uploads/aspprc/Research... I’m fairly confident that what’s going on here is that no one builds buildings out of high-hardness stainless steel. On the other hand, you can buy excellent construction screws made from 400 series stainless steel if you’re willing to pay for them —- the main problem is that they’re even more expensive than hot-dip-galvanized or fancy coated non-stainless equivalents.
      - cyberax 1y ago
        My exposure to stainless vs. carbon steel was mostly in the context of nuclear industry, where stainless was used only where it absolutely had to be used. But yeah, I spent some time looking at spec sheets, and it looks like modern stainless steels are actually quite reasonable for construction. But just too expensive for regular construction, especially compared to regular zinc coating.

by amluto 1y ago

cyberax 1y ago

??? Tool steels are not stainless, as anyone who forgot to stow away tools properly can confirm.

cyberax 1y ago

Ah, got it. You mean modern stainless steels are good enough even as tool steel replacements? It's indeed true, but at the same time, non-stainless steels are getting even better.

amluto 1y ago
I don’t have a good, accessible source for traditional tool applications, but knives are basically tools, and knifesteelnerds.con is a fantastic resource from an author who is a genuine expert: https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by-a-metallurgist-toughness-edge-retention-and-corrosion-resistance/ https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by... Compare the toughness vs hardness charts for non-stainless and stainless. You’ll find some low alloy non-stainless steels with excellent toughness at a given hardness level, but those have poor wear resistance. Other than that, the charts are just not very different. Note that even some of the very most wear-resistant steels are stainless (but you’ll have to recognize the names or look them up to tell). Of course, this says nothing about price, availability in large quantities, weldability, or ability to form them in the ways that people building large structures might want.
- cyberax 1y ago
  Hardness is not really the weakest point of stainless steels, anybody who tried high-carbon knives and got disappointed with them can attest to it. Stainless steels have lower yield strength compared to carbon steels, meaning that the stainless steels bend under stress more easily. This is not an issue for knives, but it is a big issue for construction materials.
  - amluto 1y ago
    Steel hardness and yield strength are very strongly correlated: https://wpfiles.mines.edu/wp-content/uploads/aspprc/ResearchMaterials/Publications/386-Pavlina.pdf https://wpfiles.mines.edu/wp-content/uploads/aspprc/Research... I’m fairly confident that what’s going on here is that no one builds buildings out of high-hardness stainless steel. On the other hand, you can buy excellent construction screws made from 400 series stainless steel if you’re willing to pay for them —- the main problem is that they’re even more expensive than hot-dip-galvanized or fancy coated non-stainless equivalents.
    - cyberax 1y ago
      My exposure to stainless vs. carbon steel was mostly in the context of nuclear industry, where stainless was used only where it absolutely had to be used. But yeah, I spent some time looking at spec sheets, and it looks like modern stainless steels are actually quite reasonable for construction. But just too expensive for regular construction, especially compared to regular zinc coating.