Preparation before quenching
- 1. The workpiece must undergo pre-heat treatment such as quenching and tempering, normalizing, etc.
- 2. The surface of the workpiece is not allowed to have oxide scale, dirt, oil stains, etc.
- 3. The workpiece with severe decarburization, cracks, blisters and pores on the surface cannot be flame quenched
Cast steel, cast iron, alloy steel can be slowly heated to about 300~500ºC with a quenching nozzle with a small flame to prevent cracking.
The quenching temperature of steel parts is Ac3+(80~100ºC), and the quenching temperature of iron castings is 730ºC+28×ωSi ºC -25×ωMnºC.
- 1. Commonly used fuel gas is acetylene and oxygen, and the ratio of acetylene to oxidation is 1:1.5~1:1.25.
- 2. The oxygen pressure is 0.2~0.5MPa, and the acetylene pressure is 0.003~0.007MPa (the pressure of the float-type acetylene generator is 0.006MPa). Generally, it is better for the flame to be blue and neutral.
- 3. The working pressure of coal gas is 0.003MPa, and the power of propane gas is 0.005~0.01Mpa.
Distance between flame and workpiece:
- 1. Shaft workpieces are generally 8~15mm, the lower limit for large pieces is closer, and the upper limit for small pieces with complex shapes is farther.
- 2. When the gear with modulus less than 8 is heated and quenched at the same time, the distance between the nozzle flame center and the tooth tip is preferably 18mm, and the circular linear velocity of the gear is less than 6m/min.
- 3. When the single tooth of the gear is quenched sequentially, the distance between the flame center and the tooth surface is 2~4mm.
Nozzle or workpiece moving speed:
- 1. Rotation method: linear speed is 50~200mm/min
- 2. Advance method: linear speed is 100~180mm/min
Distance between flame center and spray hole:
- 1. Continuous quenching: 10~20mm, too close, water is easy to splash and fire. Too far, insufficient or too deep hardened layer.
- 2. The water spray column should be inclined backward by 10º~30º, and there should be a partition between the water spray hole and the fire hole.
- 1. Tap water, the water pressure is 200~300kPa.
- 2. For alloy steel parts with complex shapes, use 30~40ºC for 1.5~2h, and large workpieces can be tempered by themselves (cold to about 300ºC).
The Detail Of BE-CU Die Casting Company
If you are looking for dependable volume manufacturing metal parts supplier with High pressure die casting service who offers you competitive price, good service and quality for aluminium die casting, zinc, or magnesium die casting, then BE-CU Prototype are surely a partner you are looking for to fulfill all your die casting needs. With quality service and state of art technology, BE-CU indeed claim in providing quality pressure die casting including aluminum/zamak/magnesium alloy castings to our customers all over the world.
To work with us,be-cu don’t just stop at taking your order and delivering your die casting products. be-cu are there for you at every step right from your preferred selection of aluminum die casting, Zamak die casting (Zamak 2, Zamak 3, Zamak 5, Zamak 8) or magnesium die casting products and services to post-order phase. In brief, once you become our customer, be-cu are with you every step on the way.
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