Disadvantages inside and outside

1. Fold inward

Features: There are straight, spiral, or semi-spiral zigzag defects on the inner and outer surfaces of the stainless steel tube.

cause:

1) Tube blank: loose center and segregation; serious residual shrinkage; non-metallic inclusions exceed the standard.

2) Uneven heating of the tube blank, too high or too low temperature, and too long heating time.

3) Perforation area: serious head wear; improper adjustment of the parameters of the piercing machine; aging of the piercing roller, etc.

Judgment: Internal bending is not allowed on the inside and outside of the stainless steel pipe. The internal bending of the pipe end should be ground or re-cut. The practical value of the wall thickness at the grinding place shall not be less than the minimum value required by the specification;

2. Internal scarring

Features: There are scars on the inside and outside of the stainless steel pipe, and it is generally not rooted and easy to fall off.

cause:

1) The graphite lubricant contains impurities.

2) The iron lug at the rear end of the waste pipe is pressed into the inner wall of the stainless steel pipe.

Inspection: The inner and outer surfaces of stainless steel pipes are not allowed. The end of the pipe should be ground and re-cut. The grinding depth should not exceed the negative deviation of the specification requirements, and the actual wall thickness should not be less than the small value required by the specification;

3. Alice

Feature: There are straight or intermittent nail-like cocked skins on the inside and outside of the stainless steel tube. It mostly appears on the head of the capillary and is easy to fall off.

cause:

1) The adjustment parameters of the punching machine are incorrect.

2) Stick steel on top.

3) Accumulation of iron oxide scale in waste pipes, etc.

Inspection: The inner and outer surfaces of stainless steel pipes are allowed to have no roots that are easy to fall off (or burn off during heat treatment). The peeled skin with roots should be ground or cut off.

Hangzhou Co., Ltd. is located in the west of Shenzhen City, Guangdong Province, with the Pearl River Estuary in the west, Longgang District in the east, Nanshan District and Futian District in the south, Lingdingyang in the west and Dongguan in the north. Road transportation is convenient: Guangshen Expressway, Jihe Expressway, Meiguan Expressway, Longda Expressway, Nanguang Expressway, Yanjiang Expressway, etc.; National Highway: 107 National Highway; Baoan Avenue, Nanguang, Nanping, Fulong and other roads.