Abstract: In order to meet the technical requirements of H13ESR large sizes and high-quality mould steel forged round metallographic structure and impact energy， three heat treatment processes were used to trial-produce forged round bar with diameter of 600 mm H13ESR and the inspection results were compared.The experiments have shown that： online water cooling after forged and spheroidization annealing can obtain metallographic structure NADCA#229—2016 standard AS9 at the center， and the transverse impact energy of KV2 in the center is 9.8 J； The metallographic structure is AS4 at the center by forging online water cooling ，then offline solid solution（solid solution temperature 1 040 ℃-1 060 ℃， water and air cooling alternating quenching） and spheroidization annealing， and the transverse impact energy of KV2 in the center is increased to 18.3 J；The metallographic structure is AS4 at the center by air cooling after forging，then same offline solid solution and spheroidization annealing， and the transverse impact energy of KV2 in the center is increased to 17.4 J.The experiments show that：offline solid solution heat treatment process （solid solution temperature 1 040 ℃-1 060 ℃、water and air cooling alternating quenching）， and then spheroidization annealing （850 ℃-870 ℃，730 ℃-750 ℃） can obtain metallographic structure with AS4 at the center and the transverse impact energy of KV2 in the center is increased to 17.4-18.3 J， effectively improving the microstructure and properties of H13ESR steel， meet the technical requirements of high-quality H13ESR large mold steel forging round bar.

Key words: Online Warter Cooling After Forged, Offine Solid Solution, Water And Air Cooling Alternating Quenching, Spheroidization Annealing, Liquid Precipitated Carbides, Metallographic Structure

摘要： 为了满足H13ESR大规格高品质模具钢锻圆金相组织及冲击功等技术要求，采用三种热处理工艺试制了ϕ600 mm H13ESR锻制圆钢，并对比了检验结果。试验表明：采用锻后在线水冷、球化退火锻圆心部获得的金相组织评级为NADCA#229—2016标准AS9，心部KV2横向冲击功为9.8 J；采用锻后在线水冷、离线固溶（固溶温度为1 040～1 060 ℃、水空交替淬火）、球化退火锻圆心部获得的金相组织为AS4，心部KV2横向冲击功提高到18.3 J；采用锻后风冷、相同离线固及球化退火锻圆心部获得的金相组织为AS4，心部KV2横向冲击功提高到17.4 J。试验表明离线固溶热处理工艺（固溶温度为1 040～1 060 ℃、水空交替淬火）、球化退火（温度为850～870 ℃，730～750 ℃）锻圆心部获得金相组织为AS4，心部KV2横向冲击功提高到17.4～18.3 J，有效提高了H13ESR钢组织性能，满足高品质H13ESR大型模具钢锻圆技术要求。

关键词: 锻后在线水冷, 离线固溶, 水空交替淬火, 球化退火, 网状碳化物, 金相组织