Grade 416 stainless steel: properties, fabrication and applications

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Grade 416 stainless steel is a martensitic machining bar, with improved sulfur and phosphorus machinability. This steel is sometimes used in the hardened state or not and strongly tempered, because it has a low cost and is easily machinable. Grade 416 is delivered as a bar.

Image Credit: Shutterstock / Alexandru Rosu

Martensitic stainless steels are designed for high hardness and other properties are compromised to some extent. Their useful operating temperature range is limited by their loss of ductility at subzero temperatures, and loss of strength through superheating at high temperatures.

Compared to common austenitic grades, these steels have lower corrosion resistance. They have resistance to fresh water, dry atmospheres, and mild alkalis and acids, but comparatively less strength than equivalent non-turning grades. Machining grades without high sulfur content, such as 416, are not suitable for marine or other chloride exposure. To achieve maximum corrosion resistance, the steel should be in a hardened condition with a smooth surface finish.

Grade 416 has good resistance to scaling in intermittent service up to 760 ° C and up to 675 ° C in continuous service. It is not recommended for use at temperatures above the appropriate tempering temperature.

Chemical composition

1.4005 Steel EN 10088-3: 2005
Chemical element % Here
Carbon (C) 0.06 – 0.15
Chromium (Cr) 12:00 p.m. – 2:00 p.m.
Manganese (Mn) 0.0 – 1.50
Silicon (Si) 0.0 – 1.00
Phosphorus (P) 0.0 – 0.04
Sulfur (S) 0.15 – 0.35
Molybdenum (Mo) 0.0 – 0.60
Iron (Fe) Balance

Properties

Physical property Value
Density 7.75 g / cm³
Thermal expansion 9.9 x 10-6/ K
Elasticity module 200 GPa
Thermal conductivity 24.9 W / mK
Electrical resistivity 0.57 x 10-6 .m
Mechanical property Value
Constraint of proof 450 min MPa
Tensile strength 650 – 850 MPa

Manufacturing – Must be completed using techniques which allow final heat treatment of hardening and tempering, and poor weldability.

Cold operation – This technique is not recommended. It is only suitable for minor deformations. Cracking will occur with severe deformation.

Hot work – All hot work processes should be performed after uniform heating to 2100-2250 ° F (1149-1232 ° C). Hot work below 1700 ° F (927 ° C) may cause cracking.

Machinability – The metal offers excellent machinability. It has the highest of any commonly available stainless steel, at around 85% that of a free-cutting carbon steel. Machinability is best achieved in a subcritical annealed condition.

Heat treatment – Complete annealing by heating at 815-900 ° C for ½ hour per 25 mm thickness. This is followed by cooling at 30 ° C / hour maximum up to 600 ° C and air-cooled.

Subcritical Annealing – The material is heated to 650-760 ° C and air cooled.

Hardening – Grade 416 can be hardened by heating to 925-1010 ° C, oil quenched and tempered to meet mechanical requirements.

Condition: The range of tensile strength (N / mm² or MPa) QT 650: 650-850

  • QT 900: 900-1050
  • QT 850: 850-1000
  • QT 700: 700-850
  • QT 800: 800-950

Weldability – The weldability is bad. If necessary, low hydrogen grade 410 electrodes can be used. It can be preheated to 200-300 ° C, which is followed directly by an annealing or re-hardening process, or expansion to 650-675 ° C. If the weld does not need to be hard, a grade 309 austenitic stainless steel filler rod can be used.

Applications

The fields of application of grade 416 martensitic stainless steels are the following:

  • Machined parts with automatic screw
  • Washing machine parts
  • Valve parts
  • Gears
  • Pump shafts
  • Motor shafts
  • Studs
  • Bolts and nuts

This information was obtained, reviewed and adapted from documents provided by Aalco – Stockist of ferrous and non-ferrous metals.

For more information on this source, please visit Aalco – Stockist of ferrous and non-ferrous metals.


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