30CrMnSi钢激光熔覆修复技术研究

Research on 30CrMnSi Steel Laser Melting Repair Technology

为探讨30CrMnSi钢激光熔覆修复技术,采用激光熔覆工艺进行了试验研究。采用金相显微镜对微观组织进行表征,采用显微硬度计、拉伸试验机对性能进行测试,采用扫描电镜仪观察断口形貌。研究发现,激光熔覆后的熔覆区域分为母材区、热影响区、熔合区及熔覆区4个部分。熔覆区显微硬度相比母材提高约2.5倍,表层熔覆区硬度最高,母材硬度最低。激光熔覆后抗拉强度高于母材70 MPa,熔覆正火处理后抗拉强度高于母材110 MPa。母材试样拉伸断裂为韧性断裂,断口呈韧窝形态,熔覆后试样拉伸断裂为脆性断裂,断口呈准解理断裂。熔覆后正火热处理,提高了抗拉强度及韧性。

In order to explore the laser cladding repair technology of 30CrMnSi steel,the laser cladding process was used to carry out experimental research.The microstructure was characterized by using metallographic microscopes,the performance was tested by micro-hardness testers and tensile testing machines,and the fracture morphology was observed by using scanning electron microscope.It was found that the cladding area after laser cladding was divided into four parts:base metal zone,heat-affected zone,fusion zone and cladding zone.The micro-hardness of the cladding zone was about 2.5 times higher than that of the base metal,and the hardness of the surface cladding zone was the highest,and the hardness of the base metal was the lowest.The tensile strength after laser cladding was 70 MPa higher than that of the base metal,and the tensile strength after cladding normalizing treatment was 110 MPa higher than that of the base metal.The tensile fracture of the base metal specimen was ductile fracture with a tough dimple shape,and the tensile fracture of the specimen after cladding was a brittle fracture with a quasi-cleavage fracture.After cladding,the positive heat treatment improved tensile strength and toughness.