Corrodur 4028 QT850

Alternative and trade names
Corrodur 4028, X30Cr13, 1.4028, 420, 420B, 30X13
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Description

1.4028 (X30Cr13) is used in the quenched and tempered condition in a host of constructional and fastener applications where moderate corrosion resistance is required. Due to its higher carbon content, it has good hardenability. As for other martensitic grades, optimal corrosion resistance is attained when the steel is in the hardened condition and the surface is finely ground or polished.

Related Standards

Equivalent Materials

This material data has been provided by Deutsche Edelstahlwerke Specialty Steel (DEW).

All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.

Ashby charts

Properties

General

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Mechanical

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Thermal

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Electrical

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Chemical properties

Property

Carbon

0.26 - 0.35 %

Chromium

12 - 14 %

Iron

Balance

Manganese

0.8 %

Molybdenum

0.5 %

Nickel

1 %

Phosphorus

0.03 %

Silicon

0.8 %

Sulfur

0.01 - 0.025 %

Technological properties

Property
Application areas

Automotive industry, Decorative applications, Kitchen utensils, Electronic equipment, Mechanical engineering, Pump and Valve components, Cutlery and Blades

Corrosion properties

Good corrosion resistance in moderately corrosive environments that are free of chlorides, such as soaps, detergents and organic acids. Good resistance in oxidising atmospheres up to temperatures of about 600 °C. 1.4028 is not resistant to intergranular corrosion in the asdelivered or as-welded conditions. Optimal corrosion resistance is obtained in the hardened condition with a polished surface finish. From a corrosion point of view, 1.4028 displays the same or slightly reduced resistance to corrosion than 1.4021. This is due to the higher carbon content resulting in the removal of more chromium from solution and the development of a more highly stressed microstructure in 1.4028. PRE = 12.0 – 14.0

General machinability

The machinability of this grade of stainless steel is directly related to its hardness. 1.4028 machines similar to carbon steels of the same hardness. Although it must be realised that the machining parameters will vary depending on the structure/hardness of the steel.

Heat Treatment

1.4028 can be soft annealed by holding at a temperature in the range 745 °C to 825 °C followed by slow cooling in air. 1.4021 can be hardened by holding at a temperature between 950 °C – 1050 °C followed by cooling in air or oil. Care must be taken to ensure that the time at the hardening temperature is sufficient to take any carbides that might be present into solution. After hardening and stress relieving at 200 °C, the hardness should not exceed 48 HRC, (460 HB). The tempering temperature is dependent on the desired strength. Due to the precipitation of undesirable phases, the temperature range 400° C to 600 °C should be avoided. In most cases the QT850 condition is specified and may be obtained by tempering in the temperature range 625 °C to 675°C

Hot forming

It is formable at 800-1100°C

Processing history

Quenched and tempered QT 850 and stress relieved before peeling

Welding

1.4028 is generally not welded, but if welding is unavoidable, then the following precautions should be taken: Pre-heating of the work piece to a temperature within the range 300 °C – 400 °C is required as well as a post weld tempering treatment to restore some of the ductility in the weld zone. Generally, Novonit® 4551 is recommended when a filler material is required. When using an inert or protective shielding gas during welding, care must be taken to avoid use of any hydrogen or nitrogen containing gases since contamination of the weld with nitrogen or hydrogen will adversely affect the mechanical properties. After welding the work piece must be cooled to below the martensite start (MS), temperature of approximately 120 °C before being tempered.