Microstructure and Mechanical Properties of Aer Met 100 Ultra-high Strength Steel Joints by Laser Welding
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2015年第4期
论文作者：刘奋成 YU Xiaobin HUANG Chunping HE Lihua CHEN Yuhua BU Wende
文章页码：827 - 830
摘 要：Aer Met100 ultra-high strength steel plates with a thickness of 2 mm were welded using a CO2 laser welding system. The influences of the welding process parameters on the morphology and microstructure of the welding joints were investigated, and the mechanical property of the welding joints was analyzed. The experimental results showed that the fusion zone of welding joint mainly consisted of columnar grains and a fine dendrite substructure grew epitaxially from the matrix. With the other conditions remaining unchanged, a finer weld microstructure was along with the scanning speed increase. The solidification microstructure gradually transformed from cellular crystal into dendrite crystal and the spaces of dendrite secondary arms rose from the fusion line to the center of the fusion zone. In the fusion zone of the weld, the rapid cooling caused the formation of martensite, which led the microhardness of the fusion zone higher than that of the matrix and the heat affected zone. The tensile strength of the welding joints was tested as 1 700 MPa, which was about 87% of the matrix. However, the tensile strength of the welding joints without defects existed was tested as 1832 MPa, which was about 94% of the matrix.
刘奋成，YU Xiaobin，HUANG Chunping，HE Lihua，CHEN Yuhua，BU Wende
National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University
摘 要：Aer Met100 ultra-high strength steel plates with a thickness of 2 mm were welded using a CO2 laser welding system. The influences of the welding process parameters on the morphology and microstructure of the welding joints were investigated, and the mechanical property of the welding joints was analyzed. The experimental results showed that the fusion zone of welding joint mainly consisted of columnar grains and a fine dendrite substructure grew epitaxially from the matrix. With the other conditions remaining unchanged, a finer weld microstructure was along with the scanning speed increase. The solidification microstructure gradually transformed from cellular crystal into dendrite crystal and the spaces of dendrite secondary arms rose from the fusion line to the center of the fusion zone. In the fusion zone of the weld, the rapid cooling caused the formation of martensite, which led the microhardness of the fusion zone higher than that of the matrix and the heat affected zone. The tensile strength of the welding joints was tested as 1 700 MPa, which was about 87% of the matrix. However, the tensile strength of the welding joints without defects existed was tested as 1832 MPa, which was about 94% of the matrix.
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