Feng Aixin, Zhao Jian, Lin Jinhao, Pan Xiaoming, Feng Huibin, Wang Changyu, Lu Zhengyuan
College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou 325035, China.
Zhejiang Provincial Key Laboratory of Laser Processing Robots, Machinery Industry Key Laboratory of Laser Processing and Testing, Wenzhou 325035, China.
Materials (Basel). 2022 Sep 27;15(19):6693. doi: 10.3390/ma15196693.
The automobile covering parts mold is a key piece of equipment in the automobile industry, and its drawbead is the core element that affects the life of the mold and the quality of the parts made. Due to the complex structure of the mold cavity for covering parts, there exist differences between material flow characteristics, load conditions, stress strain, failure forms and so on in the surface of different parts of its drawbead and the different directions of the same part of the drawbead, thus putting forward new requirements for material strengthening. For the differentiated lose efficacy forms of the dangerous end faces of the tension bars, this study carried out research into the effect of laser quenching-shock peening strengthening (LQ-LSP) on the organization, plastic deformation resistance and wear resistance of Cr12MoV steel. It was shown that the microhardness (722.30 HV) and residual stress (-383.84 MPa) of the specimens were further enhanced after laser quenching-shock peening composite strengthening. The residual austenite content of the specimen was reduced to 0.8%, and the eutectic carbide distribution morphology was improved. After three rounds of laser composite peening, the specimens had the smallest displacement of the nanoindentation load-depth curve, which exhibited the greatest nanohardness (20.0 Pa) and modulus of elasticity (565.25 Pa), while reducing the coefficient of friction (0.61) and surface roughness (0.152 Ra). The smooth and flat surface of the specimen with shallow and narrow plow grooves improved the resistance of Cr12MoV steel to plastic deformation and wear.
汽车覆盖件模具是汽车工业中的关键设备，其拉延筋是影响模具寿命和制件质量的核心要素。由于覆盖件模具型腔结构复杂，其拉延筋不同部位表面以及拉延筋同一部位不同方向的材料流动特性、载荷状况、应力应变、失效形式等存在差异，对材料强化提出了新的要求。针对拉延筋危险端面差异化的失效形式，本研究开展了激光淬火-冲击喷丸强化（LQ-LSP）对Cr12MoV钢组织、抗塑性变形能力及耐磨性影响的研究。结果表明，激光淬火-冲击喷丸复合强化后，试样的显微硬度（722.30 HV）和残余应力（-383.84 MPa）进一步提高。试样残余奥氏体含量降至0.8%，共晶碳化物分布形态得到改善。经过三轮激光复合喷丸后，试样纳米压痕载荷-深度曲线的位移最小，表现出最大的纳米硬度（20.0 Pa）和弹性模量（565.25 Pa），同时降低了摩擦系数（0.61）和表面粗糙度（0.152 Ra）。试样表面光滑平整，犁沟浅而窄，提高了Cr12MoV钢的抗塑性变形和耐磨性能。
