汽车高强钢纵梁热冲压实验研究

通过在自主研制的热冲压实验线上开展汽车纵梁热冲压实验，探明并对比了无涂层和不同润滑条件下Al-Si涂层22MnB5板对复杂零件热冲压成形质量和组织性能的影响。结果表明：①相比于无涂层板，涂层板能有效改善氧化脱碳现象，但涂层中形成的孔隙和裂纹容易导致零件在成形时产生破裂;采用水基石墨润滑不能消除破裂;采用玻璃润滑能有效避免破裂。②无涂层板的抗拉强度和屈服强度较高，无润滑和石墨润滑涂层板次之，玻璃润滑涂层板的抗拉强度和屈服强度较低;无涂层板的延伸率较涂层板的延伸率大。③玻璃润滑涂层板的表面粗糙度较小，无涂层板次之，无润滑和石墨润滑涂层板的表面粗糙度较大。

Experiments on Hot Stamping of Car Carling of High Strength Steel

Experiments on hot stamping of car carlings were performed on independently developed test line, and the effects of uncoated and Al-Si coated sheets of 22MnB5 under various lubrications on forming quality, microstructures and properties of complex parts were revealed and compared. The results obtained show that: ①compared with the uncoated sheet (US), the depths of oxidation and decarburization are reduced by using the coated sheet (CS), but pores and cracks are formed in the coating during forming, which results in fractures in parts. The fractures can not be eliminated under water-based graphite lubrication,and application of glass lubrication can avoid fractures. ②The US is higher in tensile and yield strengths than the CS under no lubrication and water-based graphite lubrication, and the CS under glass lubrication is lowest. The US has a higher elongation than the CS. ③The CS under glass lubrication is lower in surface roughness than the UC, and the CS under no lubrication and water-based graphite lubrication are the highest.