METHOD FOR PRODUCING ULTRA-LOW-TEMPERATURE HIGH-STRENGTH ACID-RESISTANT CONTAINER STEEL BY MEANS OF CASTING BLANK

摘要

The present disclosure discloses a method for manufacturing a high-strength acid-resistant vessel steel for ultra-low-temperature use via a cast slab, comprising the following steps: (1) defining the composition for melting; (2) heating; (3) rolling; and (4) performing a heat treatment. The present disclosure manufactures the high-strength and acid-resistant vessel steel for the ultra-low-temperature use by adopting the alloying composition design of low carbon + a small amount of chromium, and combining with a reasonable rolling process and a heat treatment process of quenching and tempering. The high-strength and acid-resistant vessel steel for the ultra-low-temperature use obtained has the mechanical properties meeting the technical requirements, with its acid-resistant property meeting the standard of NACE-TM2084-2016. Specifically, the high-strength and acid-resistant vessel steel for the ultra-low-temperature use has the following mechanical properties: a yield strength ≥ 340 MPa, a tensile strength ≥ 480 MPa, an elongation ≥ 35%, a transverse impact energy (Akv) at 1/4 thickness and -60 °C ≥ 300 J, and a crack length ratio (CLR), a crack thickness ratio (CTR) and a crack sensitivity ratio (CSR) of hydrogen-induced cracking (HIC) resistance = 0%, 0%, and 0%, respectively. The technical difficulties such as unstable low-temperature impact toughness, poor HIC resistance and unstable weldability of the high-strength and acid-resistant vessel steel for the ultra-low-temperature use via the cast slab are solved.