There are three kinds of die bore wear forms:
(1) surface roughness.
Drawing heat generated by the deformation leads to mold temperature, partial oxidation of color appear, causing a slight abrasion. Poor lubrication hole lead wire and die surface dot welding, tungsten carbide particles loose, displacement form scratches and corrugated cones and sizing work with a rough surface, a greater wear.
(2) the ellipse.
Carbide hardness uneven drawing direction does not coincide with the axis of the die orifice, the die hole single metropolitan excessive force resulting in an ellipse.
(3) an annular groove. It is typical of fatigue wear, drawing die holes during uninterrupted wire to withstand the impact, so that tungsten carbide particles fall off, forming a rough surface, rough surface and from the surface of the wire scraping metal shavings, lubricating conditions deteriorate, wear faster, ultimately bear the impact of the largest regional annular groove formed in the die orifice.
Oxidation discoloration from a rough surface an annular groove is worn constantly increasing process appears. Rational use of the mold, to extend die life method is grinding time, the die hole appeared in front annular groove on the replacement of the mold. Die promptly after each use to clean, inspect, slight wear surface polishing or grinding can be directly after the polishing process used mold, try to mold polishing amount to a minimum level, and then increase the number of mold repair. According to GB / T 61 10 provides that when the die orifice diameter approaches the maximum pore size of the molded body, the more pay attention to check the orifice surface, even a slight texture should be scrapped, causing the wire to prevent waste. Pull die life usually wear 0.01mm pulled out a few meters or to measure how much the quality of the wire, drawing medium size (diameter 4.0mm) special steel wire, carbide die life values are generally able to reach 300,000 m / 0.01mm above. Die consumption per ton of steel consumption usually carbide mandrel to represent how much quality, special steel wire mold consumption indicator is about 150-250 g / t.
Steel production, consumption of drawing dies rupture and wear two kinds. Rupture of the mold can only be scrapped, worn mold can be repaired again, so production should be reduced as far as possible the proportion of mold fracture.
Statistics show that the core rupture form:
(1) longitudinal, have broken the mold in a longitudinal 75%, of which 90% is normal after repeated repair damage after grinding mandrel wall thinning caused only a small part because of the drawing area reduction rate is too large, steel surface descaling without a net, coating well and mold caused by poor installation inserts;
(2) transverse, accounting for about 13% of the total transverse mounted mainly mold inserts bad, as the mandrel through the large round tapered or not, the bottom surface of the mold core and mold caused by poor contact sleeve. Drawing reduction rate is too large, poor lubrication are secondary causes;
(3) crack and take away meat exports break
Accounting for 6% respectively crack, mold material defects and improper reasons for each half of the drawing process, mainly the mold off the meat quality.