| With the development of industry and transportation high velocity and strong power, noise, which is caused by machine vibration, has became the third society pollution following the air-pollution and water-pollution. Study and application of damping alloys have caused the attention of people. The Fe-Cr-Al based ferromagnetic damping alloys, which possess high damping capacities, have caused more attention. Fe-l3Cr-2A1-Si damping alloy can increase the damping capacity of the alloy by 70% compared with Fe-Cr-Al when annealed at 12000C followed by air cooling. The logarithmic decrement ratio( ~) of Fe-l3Cr-2Al-Si alloy is 0.3. So the damping alloy has favorable outlook in the field of engineering. In order to be applied quickly, weldability of Fe-l3Cr-2A1-Si damping alloy and lCrl 8Ni9Ti steel, 475 0C embrittlement and mechanical property are studied in the dissertation.The way of weld is tungsten insert gas welding (TIG), and filler materials are high-alloy austenitic stainless weld wire. Welding conditions between the Fe-l3Cr-2Al-Si damping alloy and lCrl 8Ni9Ti steels are studied, and the microstructures, characteristic of melt metal are studied with metallscope. The hardness, tensile property and bending property of the welded joints are studied. The major results as follow: Excellent weld microstructure with austenite, a little ferrite and martensite are obtained. Tensile strength and bend pefformance in the welded joint are higher than that in the damping alloy. TIG, filler materials and weld process can reach the need of the dissimilar steel welding. In addition, the quality of weld isIIII-?reliable. All offer data of weld condition and reliable quality for welding Fe-l3Cr-2A1-Si damping alloy and lCrl8Ni9Ti steel.Tensile properties and bending properties of Fe-I 3Cr-2Al-Si damping alloy are studied. The tensile strength is 391-4O4MPa, and Elongation is 3.1-3.8%. These research data are necessary to design mechanical parts in damping alloy. Rupture of Fe-l3Cr-2A1-Si damping ahoy is typical brittle, and most of fracture surface morphology are cleavage terrace and river pattern, and part of which are fish-bone pattern and cleavage tongue.4750C embrittlement of the damping alloy is studied. The damping alloys are annealed at 1200 for 1 hour and then air-cooled to room temperature. The law of impact toughness value and hardness is studied after aging different time at 4280(12 and 480 0C. The major results indicate that the impact value decreases with the increasing of aging time, and retains constant after 1 50h. The hardness increases with the increasing of aging time, retains constant after 220h. The fractography of unaged Fe-I 3Cr-2A1-Si are dimple pattern near the boundary and river pattern in the intragranular. The fractography of aged Fe-i 3Cr-2A1-Si are part cleavage tongue, intergranuiar fracture and most typical river pattern, which come from the boundary.
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