Stainless Steel Grade AISI 304Cu | EN 1.4567 | DIN X3CrNiCu18-9-4

AISI 304Cu / EN 1.4567 / DIN X3CrNiCu18-9-4 is an austenitic stainless steel which is an austenitic chromium-nickel stainless steel with copper content. Except for the additional copper content, it generally has the same properties as AISI 304 stainless steel.

Due to its high copper content, it is applicable for certain unique designs in a wide range of human activities. It can also be compared with the AISI 304L grade, but with the addition of copper, which makes 304 Cu very plastic during cold drawing. It is widely used where high plasticity is required for rigid cold drawing, for example, for the manufacture of all types of screws and bolts, etc. The steel is excellent for such operations as cold drawing, thread rolling and improved processing.

Physical properties

Corrosion resistance

AISI 304Cu / EN 1.4567 is resistant to corrosion in most natural waters. In urban and rural atmospheric conditions it shows good resistance to corrosion, provided that the chloride and salt content is low. This grade of stainless steel is not resistant to seawater and as such should not be used in any structures that come into contact with seawater. Resistance to corrosion in an environment with moderate chloride and organic acids makes AISI 304Cu suitable for use in the food and beverage industry.

The corrosion resistance of the grade is very similar to that of AISI 304L / EN 1.4307, but due to the higher copper content it demonstrates increased resistance to corrosion in many acidic environments.

Technological properties

⓵ Welding

This steel is rarely welded, although it can be welded without the use of filler. If a metal filler is required, AISI 316L steel is recommended. No post-weld heat treatment is required.

⓶ Forging

Typically, this grade of metal is heated to a temperature range of 1180 - 1210 °C to ensure forging, which takes place at temperatures between 1210 and 950 °C. After forging, air cooling or water quenching follows when there is no risk of distortion.

⓷ Processing

As a result of the high copper content in this steel, the tendency to strain hardening is slowed down: the austenite phase is more stable. Drilling, threading and other machining operations can be performed relatively easily.

⓸ Heat treatment

Optimum properties of AISI 304Cu grade material are achieved after solution annealing in the temperature range of 1000 - 1100 °C followed by rapid cooling in air or water. During operation and manufacture, the time spent in the temperature range of 450 - 850 °C must be minimized to avoid embrittlement.

Mechanical properties