Abstract: The production flowsheet of steel P80R flat products (/% ： 0. 15C, 0.25Si, 1. 70Mn, 0. 012P, 0.002S, 3. 01 Ni, 0. 34Mo, 1. 07Cu, 1. 10AI) is 110 t LD-LF-RH-casting 4. 2 t ingot-breakdown 150 mmx615 mm slab-rolling to 60 mm x610 mm flats. It is obtained by examination and analysis that the Ni and Cu is seriously enriched near the cracks, the Ni content and Cu content in area near cracks are respectively up to 32. 55% ~ 33. 53% and 7. 97% 〜8. 86% , and the enrichment of Cu leads to surface grain boundary oxidation to form cracks, therefore the Cu content in steel, slab heating temperature and time should be controlled. By the process measures including decreasing Cu content in steel from 1.07% to 0. 92% , Al content in steel decreasing from 1. 10% to 0. 88% , increasing Ni/Cu from 2. 7 to 3. 3, reducing heating time at 1100 ~ 1140 ℃. from 30 ~50 min to 20 ~30 min and slab peeling treating, the occurrence rate of surface cracks of mirror plastic die steel P80R flats decreases from 70% to ≤0.5%.

摘要： P80R 钢扁材(/%：0. 15C,0. 25Si, 1. 70Mn,0. 012P.0. 002S.3. 01Ni,0. 34Mo, 1. 07Cu, 1. 10Al)的生产 流程为110 t LD-LF-RH-4. 2 t铸锭-初轧开坯150 mmx615 mm扁材-轧成60 mm x610 mm扁材。经检验和分析得 出，裂纹附近Ni,Cu严重富集，其Ni含量和Cu含量分别达32. 55% ~33. 53%和7. 97% ~8. 86% ,Cu的富集导致 表面晶界氧化，形成裂纹，应控制钢中Cu含量、加热温度和时间。通过将钢中Cu含量从1.07%降至0. 92% ,Al含 量由1. 10%降至0. 88% ,Ni/Cu由2. 7增加至3.3,1 100 ~ 1 140 ℃加热保温时间由30 -50 min降至20-30 min,钢 坯进行剥皮处理等工艺措施，镜面塑料模具钢P80R扁材裂纹出现率由70%降至≤ 0. 5%。