Austenitic heat treatment process for 72A steel wire

Abstract

The invention relates to an austenitic heat treatment process for a 72A steel wire, which is characterized in that when the heat preservation of the steel wire is determined under the conditions of different steel wire diameters d, compression ratios q, heating rates a and heating temperatures t, the following factors are presented before heat treatment: the drawing compression ratio q of the steel wire ranges from 15 to 85 percent, the diameter d of the steel wire ranges from 1.2 to 8.5 millimeters, the heating rate a ranges from 1.5 to 20 DEG C per second, and the heating temperature t ranges from 890 DEG C to 960 DEG C. The invention has the following beneficial effects of: firstly, accurately determining the needed time of heat preservation of the 72A steel wire under different wire diameters, heating rates and heating temperatures, providing great convenience for the determination of parameters of heat treatment process and causing the austenitic uniform conversion rate to be more than 99 percent; and secondly, carrying out metallographic examination, causing the grain fineness number of the steel wire after heat treatment to achieve grade eight, having uniform constituents, and enabling the sorbite rate to be more than 96 percent after patenting.

Description

technical field [0001] The invention relates to the field of steel wire ropes, in particular to an austenite heat treatment process for 72A steel wires for rope making using a regenerative steel wire heating furnace. Background technique [0002] At present, 72A steel wire is mostly used in the production of steel wire for rope making. Before drawing, the heat treatment process parameters only control the temperature of the steel wire and the time in the furnace, but the specific temperature change and structure change of the steel wire in the furnace cannot be determined. During the production process, large batches often occur. After the unqualified steel wire was inspected by metallographic structure, the inspection results showed that the heating temperature of the steel wire in the furnace was too high, and the holding time at high temperature was too long, resulting in the appearance of coarse pearlite, Widmanstatten and other undesirable structures after heat treatment...

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Problems solved by technology

[0002] At present, 72A steel wire is mostly used in the production of steel wire for rope making. Before drawing, the heat treatment process parameters only control the temperature of the steel wire and the time in the furnace, and the specific temperature change and structure change of the steel wire in the furnace cannot be determined. During the production process, large batches often occur. After the unqualified steel wire was inspected by metallographic structure, the inspection results showed that the heating temperature of the steel wire in the furnace was too high, and the holding time at high temperature was too long, resulting in the occurrence of undesirable structures such as coarse pearlite and Widmanstatten after heat treatment.

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