Kuanjun Zhu

Effect of Heat Treatment on the Low-temperature Resistance of 42CrMo Steel in Electric Power Fittings

The mechanical properties and low-temperature resistance of the 42CrMo steels utilized in electric power fittings after different heat treatments were comparatively investigated. Results indicated that a tempered sorbite with refined structure was obtained in the steels and the mechanical properties and low-temperature resistance were consequently improved after quenching + quenching + tempering and cyclic quenching and tempering, especially after the latter. The product of strength and elongation reached up to 25725 MPa% and the impact energy at -50 °C increased to 48 J after cyclic quenching and tempering as compared to 16562 MPa% and 19 J after conventional quenching and tempering. The 42CrMo steel after cyclic quenching and tempering can be considered as a suitable candidate for connection fittings in electric power transmission line.

JL1X1/LHA1-1040/550 development of aluminum alloy core forming aluminum twisted line pair splicing sleeve

UHVDC project will be prepared by JL1X/LHA1-1040/550 aluminum alloy core forming aluminum twisted line to reduce the load on the tower, improves the safety performance of the circuit, and has the function of upgrading line capacity. For such a wire, the domestic currently has no relevant research experience of line pair splicing sleeve, in order to meet the needs of practical engineering, this paper completed the pair splicing sleeve material and a compression ratio development according to the structural characteristics of this guide line; through a splicing sleeve manufacturing and testing, the development of aluminum JL1X/LHA1-1040/550 aluminum alloy core aluminum twisted wire pair splicing sleeve grip strength meets 95%RTS.

On the low noise conductor of transmission line

To reduce the level of noise of the transmission line, JL/G1A-500/35DZ low noise conductor is designed in this paper. Its structural parameters, such as protrudent height, protrudent angle and other parameters, are optimized by wind tunnel test and electric test. The preforming and synchronized tightening module device is designed. JL/G1A-500/35DZ low noise conductor is produced by this device, which solves the problems that the single thread is easily broken and the single thread in outer layer is difficultly formed and provides a basis for the application of the low noise conductor in overhead line in our country.