Dura 420/4028
EN 1.4028, ASTM TYPE 420

General characteristics

Medium-hardness martensitic grade. Corrosion resistant in water and steam. Applied for cutting utensils, surgical instruments, measuring tools, mechanical parts esp. subject to wear.

Typical applications

  • Cutting utensils and surgical instruments
  • Measuring tools
  • Mechanical parts especially in wear resistant applications
  • Springs
  • Printing industry

 

Chemical composition

The chemical composition is shown in the table below.

The chemical composition is given as % by weight.

StandardGradeCMnCrNiMoNOther
Typical40280.3012.5
EN 10088-21.40280.26-0.35≤1.512.0-14.0
EN 10088-31.40280.26-0.35≤1.5012.0-14.0
Mechanical properties

The mechanical properties of the available products are given in the table below.

 

StandardGradeRp0.2Rp1.0RmElongationImpact strengthRockwellHBHV
  MPaMPaMPa%J
Product type: Cold rolled coil and sheet
Typical (thickness 1 mm)390430640
EN 10088-21.4028 ≤ 740 ≥ 15
Product type: Hot rolled coil and sheet
Typical (thickness 4 mm)3604106002885
EN 10088-21.4028 ≤ 740
Product type: Hot rolled quarto plate
Typical (thickness 15 mm)
EN 10088-21.4028 ≥ 600800-1000 ≥ 15

1)Elongation according to EN standard:
A80 for thickness below 3 mm.
A for thickness = 3 mm.
Elongation according to ASTM standard A2” or A50.

Corrosion resistance

For more information, see Outokumpu Corrosion Handbook.

Pitting corrosion resistanceCrevice corrosion resistance
PRECPTCCT
12<10<0

PRE Pitting Resistant Equivalent calculated using the formula: PRE = %Cr + 3.3 x %Mo + 16 x %N
CPT Corrosion Pitting Temperature as measured in the Avesta Cell (ASTM G 150), in a 1M NaCl solution (35,000 ppm or mg/l chloride ions).
CCT Critical Crevice Corrosion Temperature is the critical crevice corrosion temperature which is obtained by laboratory tests according to ASTM G 48 Method F

 

 

Physical properties

Data according to EN 10088, EN 10095 or typical values.

 

DensityModulus of elasticityThermal exp. at 100 °CThermal conductivityThermal capacityElectrical resistanceMagnetizable
kg/dm3GPa10-6/°CW/m°CJ/kg°CµΩm
7.721510,5304600.65Yes

Fabrication

Welding
The microstructure of 4028 comprises tempered martensite and some carbide.The steel is normally not considered to be weldable, but if thinner gauges are occasionally welded, the use of low-hydrogen methods (MAG or TIG) is to be preferred to avoid cold cracking. Any electrodes used must be of the basic type. The martensitic steels must be preheated to temperatures above MS typically (250-400ºC). The interpass temperature should be in the same range. The heat input should not be too high or too low (0.5-1.5 kJ/mm).
Austenitic fillers are most commonly used. This avoids the post weld heat treatment that is necessary when compositionally matched filler is used.Much depends on the composition of the steel and the degree of restraint used. When there is no preheating, post weld heat treatment is necessary. However, it may be possible to weld very thin gauges without preheating.

 

Standards & approvals

The most commonly used international product standards are given in the table below.

 

StandardDesignation
EN 10088-21.4028
EN 10088-31.4028