1results about How to "Eliminate crack defects" patented technology

This invention discloses a method for eliminating internal cracks in 304L stainless steel medium-thick plates used in nuclear power plants, comprising: controlling the chemical composition of molten steel to C: 0.01-0.03%, Si: 0.3-0.7%, Mn: 1.5-1.9%, Cr: 18.05-19.5%, Ni: 9.05-11%, P≤0.03%, S≤0.005%, N: 0.02-0.08%, and controlling the ferrite content in the steel to 2.8-7.7%; and continuously casting in the continuous casting process. The cooling water volume in the secondary cooling section is controlled at 0.55–0.65 L / kg. In the hot rolling process, the slab heating temperature is controlled at 1248℃–1258℃, and the holding time is controlled at 1.8–2.5 min / mm based on the slab thickness. The final rolling temperature is controlled above 1040℃. In the heat treatment process, the hot-rolled steel plate undergoes solution treatment, with the solution treatment temperature controlled at 1065–1075℃ and the holding time controlled at 1.5–2.0 min / mm based on the steel plate thickness. This invention controls the ferrite content within a reasonable range, reducing local ferrite aggregation, thereby effectively solving the cracking defects caused by local ferrite aggregation in the hot rolling process of 304L stainless steel medium-thick plates for nuclear power applications.