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Henan Friend Metal Products Co.,Ltd

Alloy Steel Wire Drawing Requirements

Alloy Steel Wire drawing requirements

Carbon content greater than 0.6% of the hinge high strength and high strength Alloy Steel Wire, its mechanical properties and process requirements are low, medium carbon alloy wire is different from the finished product inspection often appear unqualified products. In addition to diameter tolerance, surface quality, unevenness and decarburization, etc., mainly due to lack of tensile strength or excessive volatility (barrier performance uneven), or in the torsion test hairy thorns (torsion) Crack), fracture is not straight. Especially the Group II or more high-strength Alloy Steel Wire requirements are higher, so there must be strict process operation.

1. Requirements for the previous process

 (1) wire production of high strength alloy wire wire, not only requires a good surface quality (in particular, should avoid folding), but also requires its carbon content, chemical composition, organizational structure, decarburization depth and inclusions and so on are in line with the provisions. Selection of wire diameter should be too thick, so that there is enough drawing times. Barely enough to draw the finished product, its surface quality and reverse performance is often not good.

 (2) heat treatment Heat treatment is the basis of high-strength Alloy Steel Wire, wire drawing before going through normalizing, to improve its organization. After quenching the heat treatment curve, the key is the uniformity of the furnace temperature and lead temperature. Heat treatment defects, more is the line temperature uneven, strong fluctuations in strength, and the emergence of free ferrite and so on. On T9A. Such as Alloy Steel Wire, but also to prevent decarbonization. Therefore, we must strictly implement the process system, carefully test, and do disk reclamation.

(3) pickling lubrication alloy wire surface if the residual oxide, in the torsion test will occur when the cracks burr. So pickling to ensure cleanliness. The surface can be very high requirements of the implementation of acid pickling, and pickling in the finished product before the first mechanical rust.

 Wire lubrication generally used pre-coated lime paste, or rust in the mold box in the calcium and leaching powder, and should not use the phosphate layer. The use of phosphating layer in the lead quenching process easily plug the furnace (electrical contact heat treatment furnace is not affected), and may cause hanging lead. But before the finished product and the smaller specifications of the semi-finished products can be used phosphate layer. The thickness of the phosphating film before the finished product should be a little larger to ensure that more than 8 times the drawing. Phosphating layer of the quality and thickness of the finished alloy wire twist is very related to a good phosphate film can make the alloy wire deformation is more uniform.

2. The requirements for drawing

(1) the choice of wire drawing machine Alloy Steel Wire should be no twisting of the pull, so the pulley wire drawing machine is not suitable for the production of this finished Alloy Steel Wire. The use of such equipment will affect the fatigue properties of Alloy Steel Wire (torsion test). In the past production, the coarse specifications of high strength finished Alloy Steel Wire, mostly using a single wire drawing machine. The quality of the alloy steel drawn with it is good, but the yield is low and the labor intensity is also large. At present, the linear drawing machine has been gradually promoted, it can be adjusted in a certain range to get any part of the compression rate, to meet the specifications of the Alloy Steel Wire drawing process and product quality requirements. But this equipment is too expensive, electrical lines are complex, in the high speed is still insufficient to cool. And the operation must have a certain level of technology.

There is also a large water tank drawing machine, but also suitable for drawing in the coarse specifications of high strength Alloy Steel Wire, product quality, high yield. The disadvantage is that drawing the coarse gauge alloy wire has a higher labor intensity and can not adjust the compression ratio arbitrarily. As for the fine size Alloy Steel Wire, most of the use of small water tank drawing machine drawing.

(2) cooling requires high strength alloy wire drawing heat is quite high, if not: the use of effective cooling measures, it will produce 300 ~ 500 degrees of high temperature, not only will make the lubricating film coking, and will cause changes in Alloy Steel Wire structure , So that mechanical properties decline. Therefore, it is required to reduce the drawing temperature of the alloy wire below 1500 ° C.

 (3) flatness high strength Alloy Steel Wire in the drawing process, if the outlet position slightly deviated, that may appear spiral and scattered, which is finished alloy wire never allowed to happen. So to strictly correct the location of the mold box, and pay attention to the uniform heat treatment.

(4) part of the compression rate due to high strength alloy wire deformation resistance, if the partial compression rate increases, it will cause uneven deformation, resulting in torsional cracks. Therefore, the higher the carbon content of Alloy Steel Wire, the smaller part of the pressure rate shrinkage.

 (5) Drawing speed High strength alloy wire drawing heat is very high, it is not suitable for high-speed dry pull, to ensure the quality of reverse. General dry pull speed between 60 to 150 m / min.

 (6) mold and lubrication mold to round, smoothness to be high, in order to reduce the drawing heat, the mold of the cone angle should be small points. Phosphating layer of the quality requirements of fine, solid and a certain thickness, the ability to pull many times. In order to improve the lubrication effect of the phosphating layer, the mold box can be put calcium soap

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