2018-4-13 · P355QH steel plate for Boiler Pressure Vessel. P355QH steel plate main introduction P355QH steel plate is a kind of material for boiler and pressure vessel steel. P355QH steel plates is characterised by a minimum yield strength of 280-355 MPa and by good weldability,so P355QH steel is mainly used to for manufacturing boilers.EN 1.8867 (P355QH) Steel ::MakeItFromP355QH is the EN chemical designation. It has a moderately high density among EN wrought alloy steels. In addition, it has a moderately high thermal conductivity and a very low tensile strength. The graph bars on the material properties cards below compare EN 1.8867 steel to:EN wrought alloy steels (top), all iron alloys (middle), and the entire database (bottom).