高强钢薄板切割变形的机理研究及预控分析

Mechanism analysis of cutting distortion of thin plate with high tensile strength steel for its prediction and control

  • 摘要:
    目的 为了有效地控制高强钢薄板的火焰切割精度,研究切割面外失稳变形及面内弯曲变形的产生机理,提出动态辅助加热减小火焰切割变形的工艺方法。
    方法 以3 mm厚的Q550板材为研究对象,通过火焰切割试验和三坐标测量等方法,观测到高强钢薄板切割件的面外失稳变形和面内弯曲变形;应用大变形理论的热−弹−塑性有限元计算,分析高强钢薄板切割的热力学响应,以及辅助加热对高强钢薄板切割变形的影响。
    结果 预测的切割变形趋势和数值,都与实际测量结果高度吻合;在远离割缝区域辅助加热,切割面外失稳变形可降低90%,且面内弯曲变形降低40%以上。
    结论 基于切割变形产生的力学机理,可采用不同的辅助加热工艺,提高薄板火焰切割的精度;同时,应用高通量的热−弹−塑性有限元计算,可以得到减小火焰切割变形的优化工艺,指导高强钢薄板的精度建造。

     

    Abstract:
    Objective In order to effectively control flame cutting precision of thin plate with high tensile strength steel, Generation mechanism of out-of-plane buckling distortion and in-plane bending distortion were investigated, and processing with dynamic heating was proposed to reduce flame cutting distortion.
    Method  Using Q550 plate with thickness of 3mm as research object, out-of-plane buckling and in-plane bending distortion of examined cutting specimen were observed by means of flame cutting experiment and 3-dimensional measurement. By thermal elastic plastic FE computation with large deformation, thermomechanical response during flame cutting of Q550 thin plate was examined, and influence of additional heating on flame cutting distortion of thin plate with high tensile strength steel was also considered.
    Results Both distortion tendency and magnitude of predicted results are in excellent agreement with measured data. In addition, heating the region away from flame cutting can reduce buckling distortion about 90% and in-plane bending distortion by 40%.
    Conclusion Based on the generation mechanism of cutting distortion, assisted flame heating with different processing was proposed and applied to improve the cutting accuracy with flame; furthermore, with thermal elastic plastic FE computation, optimal processing to reduce flame cutting distortion was proposed for precision fabrication of thin plate with high tensile strength steel.

     

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