拉伸载荷作用下基体表层激光离散预处理对铬镀层／45钢基开裂行为的影响

采用激光离散预处理钢基体再电镀铬层技术得到了一种新型复合结构，研究了这种新型复合结构在拉伸载荷作用下的开裂行为特征，并与无激光处理钢基体的试样在同样试验条件下的开裂特征进行了对比分析。结果表明：有激光离散预处理钢基体试样的承载能力要高于无激光预处理钢基体试样的承载能力，且有激光处理的试样开裂区域在两个激光带之间（无激光处理区），主裂纹呈现明显的周期性特征。本研究结果可归结为激光预处理钢基体不仅改善了基体表层的应力状态和力学性能，而且还改善了后续铬镀层的力学性能。

Effect of a Laser Discrete Pre-quenched Substrate on the Fracture Behavior of Chromium Coating/45 Steel Substrate under Tensile Load

The fracture behavior of the chromium coating on a laser discrete pre-quenched steel substrate is investigated by using a tensile test. The fracture behavior is compared with that of the specimen with non laser quenched steel substrate. The test results show that the bearing capacity of the specimen with laser discrete pre-quenched steel substrate is better than that of non laser pre-quenched steel substrate. For the specimen with laser pre-quenched steel substrate, the main crack occurs obviously and periodically in the non laser quenched zones. The mechanism can be attributed to the fact that the laser prequenching of steel substrate can improve not only the stress state and mechanical property of the steel substrate surface, but also the mechanical property of its corresponding chromium coating.