Summary of screw barrel renovation issues

(1) Can the barrel not be nitrided?

No! When making a new barrel, the barrel is nitrided, and the thickness after treatment is about 40-50 threads. When the first screw is worn out, the barrel is also worn to varying degrees. However, if the output drops significantly, the nitrided layer of the barrel will not exceed 20C (threads), and the thickness of the nitrided layer of each barrel is different. Therefore, some refurbishment factories can use it for more than half a year when they do the renovation for the first time, but they can't even use it for three months when they do the renovation for the second time. The reason is that the nitrided layer still has a little thickness in the first renovation, so it can be used for more than half a year. The nitrided layer is completely gone when the nitrided layer is renovated for the second time, so it is not durable. Whether the barrel is nitrided or not is the key to ensuring the service life of the screw barrel! In order to save costs, some refurbishment factories do not perform nitrided heat treatment on the barrel!

(2) How to identify whether the barrel is nitrided or not?

The color of the barrel after nitriding heat treatment will become grayish white and textured, which is different from the rusty color before. Some factories deceive people by burning it with fire, which is pure black and has no texture. A barrel can be nitrided for up to 4 times, because the iron of the barrel has been denatured and the internal structure has changed. Since the nitriding furnace needs one or two hundred screw barrels to start the furnace at a time, there is no nitriding furnace in places where mechanical hardware is not developed. Only Zhongshan Shunde in Guangdong has a nitriding furnace! Any refurbishment factory that does not nitriding the barrel will definitely not last as long as the nitriding treatment. If the old screw barrel is refurbished for the first time and the barrel is not nitrided, the time it takes depends on the original degree of wear of the barrel! Therefore, the quality of the refurbishment factory that does not nitriding the barrel is unstable. Some are used for a long time and some are not. This is the reason! The material of the old barrel determines the length of use.

(3) What is the degree of wear of the barrel and screw?

The degree of wear of the barrel and screw is different for each set of screw barrels. Different materials have different wear. Generally speaking, since the screw is active and the friction position is the screw ridge, the friction area of ​​the screw ridge is smaller than that of the barrel, so the degree of wear of the screw is greater. Generally, the degree of wear of the screw is 3:1 than that of the barrel. However, if the hardness of the screw material is much higher than that of the barrel, then the barrel is more worn!

(4) Why are some factories very cheap to refurbish? How long can the screw barrel be used after refurbishment?

Each factory has a different positioning. Some factories are positioned to quickly gain customers with low prices and low quality, so the price is very cheap; some factories rely on quality to gain long-term customers, so the cost is high, so the price is relatively higher. But there is one thing, a factory must have profits to survive. There is only wrong buying, not wrong selling. You should consider whether to choose the factory that often quotes low prices! The low price is made of domestic alloys, and the barrel is not nitrided and heat treated. At most, it is burned with fire to deceive people! If the screw barrel is made of imported alloy and the barrel is refurbished by nitriding heat treatment, the recycled material can generally be used for at least two years, which is at least 30% longer than before.