Stainless steel grades are traditionally divided into different types depending on their chemical composition. Basically stainless steel is much more alloyed and the content of chromium, molybdenum and nickel is much higher when compared to ordinary carbon steel. Stainless steel has excellent forming and welding features. Stainless steel does not corrode and it is generally highly resistant to acids.
Stainless steel fulfils the requirements of European pressure vessel standards and Pressure Equipment Directive (PED).
1.4301 is the most common stainless steel grade. The high chromium content gives it a good corrosion resistance. 1.4301 is suitable for a wide range of applications such as pipelines and tanks in process industry and equipment in food and beverage industries. The plates we store have double certificates for 1.4301 and 1.4307.
Grade 1.4404 is most suitable for applications where the better corrosion and acid resistance is needed.
The duplex grade 1.4462 combines excellent strength and corrosion resistance. Therefore the savings are gained from the plate thickness and material costs. Duplex stainless steel is an excellent choice for the needs of pulp industry.
Stainless steels are available in several surface finishes which gives them the desired aesthetic appearance as well as the sensitivity to corrosion, e.g.:
1D = hot rolled, heat treated, pickled
2B = cold rolled, heat treated, pickled, skin passed with polishing rollers
Please note: there are giant plates with dimensions 2000×8000 mm and 3000×9000 mm in our stock!
- Dimensions
- Welding
The most common stainless steel plate thicknesses and sizes available in our stock:
| Grade | Surface condition | Thickness (mm) | Width x length (mm) |
|---|---|---|---|
| 1.4301 / 1.4307 | 2B | 1–3 | 1500 x 3000 1500 x 6000 |
| 1D | 4–6 | 1500 x 3000 1500 x 6000 2000 x 6000 |
|
| 8–20 | 1500 x 3000 1500 x 6000 2000 x 6000 3000 x 9000 |
||
| 25–60 | 1500 x 3000 2000 x 6000 |
||
| 1.4404 | 2B | 1–3 | 1500 x 3000 1500 x 6000 |
| 1D | 4–6 | 1500 x 3000 1500 x 6000 2000 x 6000 |
|
| 8–20 | 1500 x 3000 1500 x 6000 2000 x 6000 3000 x 9000 |
||
| 25–80 | 1500 x 3000 2000 x 6000 2000 x 8000 |
||
| 100 | 2000 x 4000 | ||
| 1.4462 | 1D | 4–50 | 2000 x 6000 |
During welding attention should be paid to prevention of the cold cracking behavior of the steel and the mechanical properties of the weld joint. The optimal working temperature and the cleanliness of the surfaces are both crucial. An effective mean to avoiding cold cracking is preheating. It delays the cooling of the weld region and thereby slows the hydrogen effusion.
Steel’s susceptibility to cold cracking and the need for preheating can be estimated by the carbon equivalent. The most often used formula for this is:
CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15
Experience has showed that the weldability of the steel is at its best at the room temperature when the CEV is below 0,4 %.
| CEV (%) | |
|---|---|
| < 0,41 | steel is good for welding |
| 0,41–0,45 | austenitic welding filler metals |
| 0,45–0,59 | preheating and heat treatment |
| 0,6–0,8 | difficult to weld |
| > 0,8 | not suitable for welding |
Welding conditions have a crucial effect on mechanical properties of welding joints. Thermal effects of welding are not allowed to weaken the steel properties in the way the construction would not meet the requirements set. Mechanical properties should be achieved both welding metal and heat-affected-zone (HAZ).
