Thyssenkrupp Steel Europe has manufactured pressure vessel steels for more than 50 years with both of the European (EN10028) and the American (ASME / ASTM) standards. The manufacturing of pressure vessel steels is tightly regulated. European pressure vessel steel requirements are in line with the Pressure Equipment Directive (PED).
Wide range of pressure vessel steel applications include e.g. process tanks, autoclaves, heat exchangers, steam and hot water boilers, pipework and various accessories and fittings under pressure such as valves.
Pressure vessel steel grades are divided into three different categories:
- Carbon steels are the basic pressure vessel steels. They are the best choice for equipment withstanding low heat and corrosion. We stock P355GH / NL2 steels that are low-alloyed and fine-grained pressure vessel steel with double certificates. The steel is suitable for both high (400 ° C) and low (-50 ° C) temperatures.
- Heat resistant steels are alloyed with chromium, molybdenum and nickel to improve the heat and corrosion resistance. 16Mo3 and 13CrMo4-5 heat resistant alloyed steels can be found from our stock. Thanks to their special structure these steels are suitable for use even in high up to 500 ° C temperatures.
- Stainless steels are more alloyed and their chromium, molybdenum and nickel contents are high. Stainless steels are used e.g. in the food and pharmaceutical industries where oxidation must be avoided.
- Dimensions
- Welding
- More details
The most common pressure vessel steel plate thicknesses and sizes available in our stock:
| Grade | Thickness (mm) | Width x length (mm) |
|---|---|---|
| P355GH/NL2 | 6–60 | 2500 x 6000 |
| 16Mo3 | 8–60 | 2500 x 6000 |
| 13CrMo4-5 | 8–60 | 2500 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).
Extra information can be found from the pdf-documents below:
