Reducer, used for connection between two pipes of different diameters. According to different shapes, it can be divided into two types: concentric reducer and eccentric reducer.

Process document of concentric eccentric reducer

1. Scope: suitable for pressing steel concentric and eccentric reducer.

2. Pressing: Steel concentric and eccentric reducers are usually cold worked, i.e. pressed on a hydraulic press in a cold state (sometimes hot working).

3. Process flow: re inspection of raw materials → blanking → shot blasting → lubrication → pressing → heat treatment → shaping → shot blasting → groove processing → nondestructive testing → finished product inspection → anticorrosion → identification → warehousing.

4. Pressing process:

4.1 concentric and eccentric reducers are large and small, and the deformation degree of each pass is calculated by necking coefficient D / D (D is the diameter after necking, D is the diameter before necking).

4.2 the necking coefficient of different materials is different. The strength of normalized steel pipe is higher, so it needs to be pressed after annealing, but generally it is not annealed, unless it is difficult to press.

4.3 the necking coefficient of stainless steel and carbon steel low alloy steel is different, the first pressing of stainless steel can reach 0.65 ~ 0.7, and the later several passes are 0.85 ~ 0.9. Sometimes, it is necessary to press after heat treatment. Carbon steel and low alloy steel are generally 0.7 ~ 0.9. Generally, continuous pressing can be carried out for 1 ~ 3 times. However, different material properties may lead to continuous pressing for 4 times.

4.4 lubrication during pressing: No.3 industrial grease + lime is used for stainless steel in pressed state, butter + graphite powder is used for carbon steel and low alloy steel, and graphite powder is used for hot pressing.

4.5 the pressing die can be pressed only after the die is processed and the mold test is qualified.

.4.6 for mold repair, check the mold after each pressing to repair the scratch on the inner surface of the mold, and the surface smoothness is 6.3 μ M.

5. Process document management:

5.1 process documents must be sent to the team before pressing.

5.2 contents of process documents: ① process flow card. ② The drawings and documents should reflect the standard requirements (including the special requirements of customers) and focus on the safety of products.

5.3 Who needs to sign in the manufacturing process.

5.4 process flow cards and drawings must flow with products in each process.