Stainless Steel 1.4021: Martensitic Machining Bar Properties

Martensitic stainless steels are designed for high hardness, and other properties are compromised to an extent. Their functional operating temperature range is restricted by their loss of ductility at sub-zero temperatures, and loss of strength by over-tempering at high temperatures.

Alloy designations of 1.4021 is similar, but it may not be a direct equivalent to: 420, UNS42000, 1.4021, 1.4024, 1.4028, 1.4029, 1.4030, and 1.4034. It is supplied in the form of a bar.

Chemical Composition

1.4021 Steel	EN 10088-3:2005
Chemical Element	% Present
Carbon (C)	0.16 - 0.25
Chromium (Cr)	12.00 - 14.00
Manganese (Mn)	0.0 - 1.50
Silicon (Si)	0.0 - 1.00
Phosphorous (P)	0.0 - 0.04
Sulphur (S)	0.0 - 0.03
Iron (Fe)	Balance

 

Properties

Physical Property	Value
Density	7.75 g/cm³
Thermal Expansion	10.3 x 10-6/K
Modulus of Elasticity	200 GPa
Thermal Conductivity	24.9 W/m.K
Electrical Resistivity	0.55 x 10-6 Ω.m

Bar - Up to 160mm Dia/Thickness	EN 10088-3:2005
Mechanical Property	Value
Proof Stress	500 - 600 MPa
Tensile Strength	700 - 950 MPa
Elongation A	12 - 13%

 

Fabrication

Fabrication must be carried out by methods that allow for poor weldability, as well as for a final harden and temper heat treatment.

Cold working – It is not recommended, It is only suitable for minor deformation. Cracking will occur due to severe deformation.

Hot working - Hot working processes should be carried out after uniform heating to 2100-2250°F (1149-1232°C). Hot working below 1700°F (927°C) could result in cracking.

Machinability - Grade 420 offers very good machinability, the highest of any of the commonly available stainless steels. It is achieved best in sub-critical annealed condition.