Steel for low temperature pressure vessel and its manufacturing method

摘要

As a steel for low pressure pressure vessels, the mass percentage of chemical elements is C 0.02-0.08%, Si 0.10-0.35%, Mn 0.3-0.8%, Ni 7.0-12.0%, N≤0.005%, Al 0.015-0.05%, Nb 0.1 -0.3%, Ca and / or Mg 0.001-0.005%, randomly selected V and / or Ti 0.1-0.3%; the rest are Fe and other unavoidable impurities. The method of manufacturing the steel for a low pressure pressure vessel includes: (1) Smelting: LF + RH refining after converter smelting; (2) continuous casting; (3) hot rolling; (4) quenching heat treatment; (5) tempering treatment; Includes steps. The steel for the low pressure pressure vessel has high low temperature impact toughness.