激光熔化沉积制备核电级Z2CN19-10N不锈钢构件组织与力学性能研究

Microstructure and mechanical properties of nuclear grade Z2CN19-10N stainless steel components prepared by laser melting deposition

利用激光熔化沉积技术制备核电级Z2CN19-10 N奥氏体不锈钢板,利用金相显微镜,扫描电镜技术,对沉积态及热处理态组织进行分析,测试沉积态及热处理态试样室温拉伸性能。结果表明:激光熔化沉积Z2CN19-10 N不锈钢沉积态组织由沿沉积增高方向贯穿多层外延生长的柱状晶组成,柱状晶内包含多个细长整齐排列的树枝晶,奥氏体基体上分布着大量沿沉积增高方向排列的残余铁素体;固溶处理后残余铁素体消除,奥氏体基体上析出大量碳化物。Z2CN19-10N奥氏体不锈钢沉积态组织具有良好的室温拉伸性能,抗拉强度达539 MPa,屈服强度264 MPa,延伸率54%,达到锻件水平。

The nuclear grade Z2CN19-10N stainless steel plate was prepared by laser melting deposition technology.The microstructure of the deposited and heat-treated samples was analyzed by metallographic microscope and scanning electron microscope,and the tensile properties of the samples were tested at room temperature.The results show that the microstructure of Z2CN19-10N stainless steel deposited by laser melting is composed of columnar crystals that grow through multilayer epitaxial growth along the increase direction of deposition.The columnar crystals contain a number of elongated dendritic crystals arranged in neat order.A large number of ferrites arranged along the increase direction of deposition are distributed on the austenitic matrix.After solid solution treatment,ferritic elimination was involved,and a large number of carbides were precipitated on the austenite matrix.The deposited structure of Z2CN19-10N austenitic stainless steel has good tensile properties at room temperature,tensile strength up to 539 MPa,yield strength up to 264 MPa,elongation up to 54%,reaching the forging level.