Are there no temperature requirements for starting up equipment made of 2 1/4Cr-1Mo-1/4V for the first time?
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For the hydrogenation unit, with reactors made of 2 1/4Cr-1Mo-1/4V material, is it still required to start up the unit in a hot state? It shouldn’t be necessary in an environment without hydrogen, right? Also, for the first start-up of 2 1/4Cr-1Mo, is it necessary to increase the temperature first before raising the pressure? Is the new standard 50°C? I asked the experts for advice.
1.25Cr0.5Mo is a type of steel plate used for boiler and pressure vessel applications. The 1.25Cr-0.5Mo steel plates used for cylinders and heads (including the base layer of composite steel plates), in addition to meeting the requirements listed below, must also comply with the other relevant specifications specified in ASMESA387/SA387M Gr11 Class 2. 1.25Cr-0.5Mo steel should be produced using an electric furnace or an oxygen converter with vacuum degassing and refining processes; it should be a essentially fine-grained killed steel. Chemical composition: C: ≤0.15, Si: 0.44–0.86, Mn: 0.35–0.73, P: ≤0.10, S: ≤0.007, Cr: 0.94–1.56, Mo: 0.40–0.70, Ni: ≤0.25, Cu: ≤0.20, Sb: ≤0.0030, Sn: ≤0.015, As: ≤0.016; impurities: ≤3 ppm. Mechanical properties: Tensile strength at room temperature (MPa): 515–690; Yield strength at room temperature (MPa): ≥310; Elongation at room temperature (%): ≥18; Reduction of area at room temperature (%): ≥45. Charpy impact energy at -20°C (V-notch J): The average value of three specimens should be ≥54, with one specimen being allowed to have a value of ≥47. Yield strength at high temperatures of 475°C: σ0.2 at 475°C ≥185.5 MPa, and σb ≥348 MPa. Corresponding national standard steel grade: 14Cr1Mo