Laser cladding repair technique for engine crankshaft

Abstract

The invention relates to an engine crankshaft laser cladding repairing technology based on the following steps. A: the crankshaft surface is treated with oil removing stain removal; B: a DL-HL-T10000 type CO2 laser is selected; a working table with numerically-controlled machine tool is applied; an auto-feeding powder apparatus for laser is used to delivered a Fe-based or Ni-base self-fusing alloy powder to a molten pool, and the Fe-based or Ni-base self-fusing alloy powder is repaired and strengthed on the surface of the crankshaft. The technological parameter features that the cladding power P ranges between 1,000w and 10,000w; the spot dismeter D is between 2mm and 20mm; the scanning speed is at 200 mm per min to 2000mm per min; the overlapping rate is from 20 per cent to 40 per cent. The laser cladding technology of the invention features no pollution, high productivity, low energy consumption, small machining allowance and lower comprehensive cost. In addition, the laser cladding is good to the repair of the wear parts, such as strong associativity, small residual stress, no machining deformation, high surface hardness as well as good abrasion resistance, and becomes a process technology with great developing potential in repairing the components.

Description

technical field [0001] The invention belongs to the technical field of laser cladding, and in particular relates to a laser cladding repair process for an engine crankshaft. Background technique [0002] The crankshaft is the most important part of the engine, currently made of ductile iron and steel. The crankshaft bears a lot of bending and torsional stress during the working process, which makes the journal wear and fatigue fracture a common damage form of the crankshaft, and these damage forms originate from the surface, so the surface strengthening and repair of the crankshaft is particularly important. [0003] The existing surface strengthening and repairing methods of the crankshaft include medium and high frequency induction hardening, nitriding treatment and nitrocarburizing, shot peening strengthening and thermal spraying strengthening. Although the above-mentioned surface treatment method can improve the wear resistance, the bonding strength between the coating ...

AI Technical Summary

Problems solved by technology

Although the above surface treatment method can improve the wear resistance, the bonding strength between the coating and the crankshaft is not good, and it is also prone to cracks or coating peeling due to local stress concentration, which reduces its strengthening effect to a certain extent.