Phase transformation and blanking accuracy of boron steel B1500HS during hot blanking
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摘要: 為了研究熱沖裁零件微觀組織及尺寸精度的變化規律，采用不同的沖裁溫度和模具間隙比對B1500HS鋼板進行了熱沖裁試驗.根據冷卻曲線，研究了沖裁溫度對硼鋼組織轉變和零件力學性能的影響；根據落料件的尺寸，分析了沖裁溫度和模具間隙比對尺寸精度的影響；通過觀察零件的斷口形貌，分析了沖裁溫度對斷口質量的影響.結果表明：當沖裁溫度一定時，落料件的尺寸隨著模具間隙比的減小而增大；當模具間隙比一定時，落料件的尺寸誤差隨著沖裁溫度的降低出現“正—負—正”的增長波動趨勢；當沖裁溫度為600~650℃或750~800℃時，落料件具有較高的沖裁精度；落料件的硬度隨著沖裁溫度的升高而增大，當沖裁溫度為650~800℃時，落料件的組織為馬氏體，硬度值HV約為550；沖裁斷面光亮帶的寬度隨著沖裁溫度升高而增大.Abstract: To investigate the microstructure transformation and the change of the dimensional accuracy of the hot blanking parts, the hot blanking experiments for B1500HS steel were performed with different temperatures and die clearance ratios. The effects of blanking temperature on the phase transformation and mechanical properties of steel were analyzed using the cooling curves. The effects of blanking temperature and die clearance ratio on the dimensional accuracy of the hot blanking parts were analyzed based on the measured diameter of the parts. The fracture morphology of the parts was observed, and the effect of blanking temperature on the fracture quality was analyzed. The results show that, with decreasing die clearance ratio, the diameter of the blanking parts increases at the same blanking temperature. When the die clearance ratio remains constant with decreasing blanking temperature, the dimension deviation of the parts has a fluctuation tendency of "positive growth-negative growth-positive growth". The blanking parts have a higher accuracy as the blanking temperature is in the range of 600-650℃ or 750-800℃. While increasing the blanking temperature, the micro-hardness of the parts increases. The microstructure of the parts is full martensite and the micro-hardness is about HV 550 as the blanking temperature is in the range of 650-800℃. Furthermore, increasing the blanking temperature, the width of burnish zone increases.
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Key words:
- boron steel /
- hot stamping /
- accuracy /
- microstructure /
- phase transformation
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參考文獻
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