440C
{{Short description|Martensitic stainless steel type}}
440C (UNS designation S44004) is a martensitic 400 series stainless steel,{{Cite book|last=Cramer|first=Stephen D.|url=https://www.worldcat.org/oclc/712545628|title=ASM handbook, Volume 13B- Corrosion: Materials|last2=Covino|first2=Bernard S.|publisher=ASM International|year=2005|isbn=978-1-62708-011-8|location=Materials Park, OH|pages=56|oclc=712545628}} and has the highest carbon content of the 400 stainless steel series. It can be heat treated to reach hardness of 58 to 60 HRC. It can be used to make rolling contact stainless bearings, e.g. ball bearings and roller bearings. It is also used to make knife blades.
440C has the highest strength, hardness, and wear resistance of all the commonplace 440-series stainless alloys, with high carbon content and moderate corrosion resistance.{{cite web |title=440C Stainless Steel Products and Specifications - Penn Stainless Products {{!}} Penn Stainless Products |url=http://www.pennstainless.com/stainless-grades/400-series-stainless/440c-stainless-steel/ |website=www.pennstainless.com}}
Composition
| class="wikitable"
|+Chemical Composition (wt%){{cite web|title=AISI 440C Knife Steel Composition Analysis Graph and Information Details|url=http://zknives.com/knives/steels/steelgraph.php?nm=440c&hrn=1&gm=0|access-date=5 August 2013}} !C !Cr !Mn !Si !Mo !P !S !Fe |
| 0.95-1.20
|16.0-18.0 |1.00 |1.00 |0.75 |0.040 |0.030 |Balance |
Mechanical properties
| class="wikitable"
|+Typical Mechanical Properties as a Bar {{Cite book|last=ASM International Handbook Committee.|url=http://worldcat.org/oclc/1117847668|title=ASM Handbook, Volume 01 - Properties and Selection: Irons, Steels, and High-Performance Alloys|publisher=ASM International|year=1990|isbn=978-1-61503-160-3|oclc=1117847668}} !Heat Treatment !Young's Modulus (GPa) !0.2% Offset Yield Strength (MPa) !Tensile Strength (MPa) !Elongation (%) !Rockwell Hardness !CTE (0-100 °C) (μm/m) !Thermal Conductivity (at 100 °C) (W/m*K) |
| Annealed
|200 |425 |760 |14 |97 HRB |10.2 |24.2 |
| Tempered at 315 °C
|200 |1900 |1970 |2 |57 HRC |10.2 |24.2 |