| 316L stainless steel is one of typical austenitic stainless steel, which has been widely used in petrochemical industry, navigation possessing, energy exploitation because of its excellent toughness, plasticity and resistance to corrosion. However, due to its poor resistance to atmospheric corrosion and wear, 316 L stainless steel suffers from serious erosion and damage, such as erosion and cavitation corrosion. Therefore, it was important to improve the microhardness and wear resistance by surface modification technique. With the development of chemical surface heated treatment, plasma surfacing and vacuum cladding technology, they provides an effective approach for 316 L stainless steel surface hardening coating preparation, repair and remanufacturing.B-RE penetrating layer and Colmonoy alloy layer(78 and 88 system) were prepared by solid boronizating, plasma surfacing and vacuum cladding technology. Microstructure, constituent phases and microhardness of the modified layer were investigated by means of SEM, EDS, XRD and microhardness tester, respectively. Meanwhile, the wear, cavitation erosion and solid-liquid erosion corrosion resistance in 3.5% NaCl solution of the modified layer were also evaluated using an ultrasonic vibrator and erosion corrosion tester.Experimental results showed that the penetrating layer was compact and flat. Outer layer of the penetrating layer exhibited a single FeB phases, while inner layer was mainly composed of Fe2 B, Cr2 B and γ-Fe matric phase and Cr element segregated. The microhardness of the penetrating layer was 1654 HV. The relative wear resistance of the penetrating layer could reach 10.43. The main wear mechanism of the layer was abrasive wear. The cavitation erosion and the erosion corrosion resistance of the layer was also improved compared to the substrate, which was 10 times larger than that of the substrate. Colmonoy alloy layer(78 and 88 system) prepared by plasma surfacing and vacuum cladding technology was compact and uniform. A typical metallurgical bonding between the layer and the substrate was appeared. Colmonoy alloy layer(78 and 88 system) was mainly composed of γ-Ni solid solution, FeNi3 simple compound, chromium carbide, boride and WC. The block-shaped WC was dispersively distributed in the modified layer. The relative wear resistance of the modified layer prepared by plasma surfacing technology was 11.68 and 53.09, respectively. The cavitation erosion and the erosion corrosion resistance of the modified layer were also improved. While the cavitation erosion and the erosion corrosion resistance of the Colmonoy alloy layer(88 system) were much better, which were 5 and 25 times larger than that of the substrate, respectively. The relatively wear resistance of Colmonoy alloy layer(78 and 88 system) prepared by vacuum cladding technology was 36.5 and 38.93, respectively. Colmonoy alloy layer(78 and 88 system) exhibited an improved cavitation erosion and erosion corrosion resistance. The Colmonoy 88 alloy layer prepared by plasma surfacing technology exhibited the best comprehensive properties. |
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