The use of as-rolled cold forming steels opens new potential for lightweight construction in the automotive industry. Cold-rolled grades with a tensile strength up to 1100 MPa are on the market. However, the high strength limits the cold forming performance. A local softening in areas of high degree of deformation can be a solution to this conflict. In this work, basic studies on softening of a sheet metal were conducted. A fiber-coupled diode laser with a maximum laser power of 12 kW and a rectangular laser spot were used for laser heat treatment of the steel grade ZE 1100. It is shown that a local softening can be achieved even with short term heating. The softening is due to partly or full recrystallization of the microstructure. The tensile strength and the yield point can be reduced by about half, and the elongation at break can be increased by a factor of seven.

中文翻译：

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冷成型钢的局部激光软化

冷成型冷成型钢的使用为汽车行业的轻量化结构开辟了新的潜力。市场上有抗拉强度高达 1100 MPa 的冷轧钢种。然而，高强度限制了冷成型性能。高度变形区域的局部软化可以解决这种冲突。在这项工作中，对金属板的软化进行了基础研究。使用最大激光功率为 12 kW 的光纤耦合二极管激光器和矩形激光光斑对钢种 ZE 1100 进行激光热处理。结果表明，即使是短期加热，也可以实现局部软化。软化是由于微观结构的部分或完全再结晶。抗拉强度和屈服点可降低一半左右，