Is 19Mn6 boiler steel a high-temperature structural steel?
19Mn6 boiler steel is the German standard number of high-temperature structural steel, equivalent to the national standard Q345R and the European standard P355GH. 19Mn6 high-temperature and high-pressure resistant boiler steel plates are mainly used in the production of power station boiler drum drums.
19Mn6 boiler steel refers to a steel type that can still show characteristics at higher temperatures, with local temperatures up to 600°C, and under time load conditions. The product shape adopts the definition in the European Coal and Steel Community standard EURONORM79. The weight of all steel types in the standard is calculated based on a specific gravity of 7.85 kg/dm3. The steel grades under the standard are: UHI, HI, HII, 17Mn4, 19Mn6, 15Mo3 are usually hot rolled and normalized, while 13CrMo44 and 10CrMo910 are normalized and quenched and tempered. Relevant regulations: (TRB) Pressure Vessel Technical Regulations, TRD Steam Boiler Technical Regulations, TRG High Pressure Gas Technical Regulations. If the test temperature is not specified, the test shall be carried out at 300°C. Tensile strength 350-630 Newton/mm2, yield strength: 185-310 minimum Newton/mm2, elongation 17-25%, 0-20° impact minimum 27-31J. Status: normalizing, heat treatment normalizing temperature 890-950°C, stress relief annealing 520-620°C.
Can 19Mn6 boiler steel be used as boiler forgings instead of 20 and 25 steel after forging and heat treatment? By analyzing the chemical composition, mechanical properties and metallographic structure of the raw materials to determine whether they meet national standards, and then proceeding with blanking, forging, heat treatment, sampling, testing and structural performance analysis, it was found that all performance indicators of 19Mn6 forgings can be It meets the inspection standards and can be used as forgings instead of 20 and 25 steel. And it is determined that the forging temperature of 19Mn6 steel forgings is: heating temperature 1200 ℃, heat preservation 1 min·mm-1, initial forging temperature 1100~1150 ℃, final forging temperature ≥850 ℃, air cooling after forging, normalizing heat treatment after forging, heating The temperature is 910 ~ 940 ℃, and the holding time is 1 min·mm-1 air cooling.