【摘要】 研究普通轧制和TMCP控制轧制工艺对S355J0级超厚热轧H型钢低温冲击的影响，并对试样冲击断口形貌和显微组织进行了观察分析。结果表明，普通轧制下低温冲击断口形貌呈现典型的解理断裂形貌，而TMCP控制轧制下低温冲击断口形貌呈现等轴韧窝+局部撕裂韧窝形貌，对应的金相组织显示粗大的珠光体和针状铁素体所形成的混晶组织是导致超厚热轧H型钢低温冲击性能低的主要原因。通过采用道次温度及降速控制，实现高温再结晶区和低温非再结晶区相结合的控轧轧制生产工艺，其生产S355J0级超厚热轧H型钢晶粒度可细化至8.5级～9.5级，0℃耐低温冲击功达到100 J以上。更多还原

【Abstract】 The effects of ordinary rolling and TMCP controlled rolling processes on the low-temperature impact of S355J0 grade ultra-thick hot-rolled H-beam were studied, and the impact fracture morphology and microstructure of the samples were observed and analyzed.The results showed that the low-temperature impact fracture morphology under ordinary rolling presents a typical cleavage fracture morphology, while the low-temperature impact fracture morphology under TMCP control rolling presents an equiaxed dimple+local tearing dimple morphology, and the corresponding metallographic structure showed a mixed crystal structure formed by coarse pearlite and needle like ferrite, which was the main reason for the low low-temperature impact performance of ultra-thick hot-rolled H-beam.By adopting pass temperature and speed reduction control, a controlled rolling production process combining high-temperature recrystallization zone and low-temperature non recrystallization zone was achieved. The grain size of S355J0 grade ultra-thick hot-rolled H-beam were refined to 8.5 ～ 9.5 grades, and the low-temperature impact energy at 0 ℃ reached over 100 J.更多还原