Numerical Simulation And Deformation Discipline Of Stainless Steel-Carbon Steel Laminated Sheet During Laser Bending Process

Stainless steel-carbon steel laminated sheets(SCLS) is a new kind of composite materials which combines matrix(carbon steel) and cladding layer(stainless steel) with a special preparation technique and have advantages of both materials. Compared with the single-component metal plate, SCLS not only meets performance requirements, but also save a lot of precious metal and reduce materials’prices a lot. So it has a broad application prospects in aerospace, shipbuilding, petrochemical, marine development and other areas. Laser bending is a newly developed flexible forming technology which is suitable for forming plates and shells. There are no needs of molds, contacts or external forces in laser bending process; meanwhile, it has good capability of forming complex shape work pieces. So it has enormous potentials in new product development and small batch production. Because of the bonding interface and the properties differences between the materials of cladding layer and matrix, SCLS has big differences compared with single component metals during laser bending process.In this paper,1Cr18Ni9Ti/Q235A/1Cr18Ni9Ti SCLS is studied. A multi-layer SCLS finite element model based on ANSYS software and thermal elastic-plastic theory is established, and its laser bending process and deformation behavior are simulated. The main contents and results are as follows:(1) Considering characteristics of the bonding interface and pulsed laser, APDL language in ANSYS software is used to program the SCLS pulsed laser bending process based on thermal elastic-plastic finite element theory, a three dimensional thermal-structural order coupled finite element model for SCLS’pulsed laser bending is established, and the model is optimized.(2) According to the finite element model, temperature, stress-strain and displacement distribution are analyzed during pulse laser bending process. The temperature, stress and strain have a cyclical shock in cladding layer during pulse laser bending process. Temperature transfers smooth at the bonding interface, but stress and strain have a mutation; after deformation, the cladding layers show lateral tensile stress, while the matrix shows transverse compressive stress. Bending experiments are conducted using laser processing system with temperature and displacement measuring devices, and the results are verified the accuracy of the finite element model compared with simulation results. (3) Laser bending processes of SCLS under different parameters are simulated, and deformation disciplines are analyzed. Bending angles of SCLS are related with plastic strain gradient in thickness direction, increasing with the increase of is laser power, scanning times, SCLS’width and thickness ratio of stainless steel/carbon steel, while decrease with the increase of defocus dimension, scanning speed, SCLS’thickness. According to the obtained laser bending rules, appropriate process parameters are selected and a50°corrugated bulkhead is achieved.In this paper, SCLS’bending characteristics during laser bending process are revealed using numerical method, and it has a big significance for guiding SCLS’laser bending experiments, avoiding forming failures and broaden applications of SCLS.