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.

Using Q550 plate with thickness of 3 mm 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.

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%.

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 high-precision fabrication of thin plate with high tensile strength steel.