拉应力对热轧复合板界面组织的影响

Influence of Tensile Stress on Interface Microstructure of Hot rolling Clad Plate

以5.5mm厚的Q235A碳钢板材为基材,2.5 mm厚的304奥氏体不锈钢板为覆材,制备了碳钢/不锈钢复合板。研究了单道次轧制碳钢/不锈钢真空复合板界面组织及拉应力对界面组织的影响。结果表明:热轧复合板界面析出片状碳化物,随轧制压下率增加,片状碳化物更加密集。在318 MPa屈服应力作用下,复合板基板表面产生韧窝,片状碳化物基本未断裂;在345.5 MPa应力作用下,基材裂缝变得宽而深,碳化物断裂;试样受到368.97 MPa应力作用时,碳钢表面碳化物受力后碎裂,凹坑数量增加,深度减小。在384.73 MPa(抗拉强度)应力作用下,试样的韧窝密集而细小,粒子碎裂成为小块,基体中产生了很多破坏性裂纹。

The carbon steel/stainless steel clad plates were prepared with 5.5 mm thick Q235A carbon steel plate as substrate and 2.5 mm thick 304 austenitic stainless steel plate as cladding material. The effect of tensile stress on the interface structure of carbon steel/stainless steel vacuum clad plate prepared by single rolling was studied. The results show that flaky carbides precipitate in the interface, and it is denser with reduction rate increasing. The surface of the base plate produces dimples at 318 MPa yield stress, and the flaky carbides are basically not broken. The surface cracks of the base plate become wide and deep, and the carbides break under the action of 345.5 MPa stress. The carbides in the carbon steel surface crack under the action of 368.97 MPa stress, but the number of dimples increases and its depth decreases. Under the 384.73 MPa(tensile strength)stress, the dimples of the samples are dense and small, the particles are broken into small pieces,and the matrix produces many destructive cracks.