JB/T 7023-2014Thrust Runner Forgings for Hydraulic Generators - Technical Specification (English PDF)

3.1

The purchaser shall indicate the adopted standard, material designation, corresponding technical requirements specified by the supplier and the purchaser and inspection items as well as inspection items beyond this standard in the order contract.

3.2

The purchaser shall provide rough machining drawings indicating the dimensions and technical requirements of forgings (finish machining dimensions if necessary).

4.1 Smelting

Steel used for forgings shall be smelted in basic electric furnace. As agreed by the purchaser, other smelting methods meeting the requirements of this standard may also be adopted.

4.2 Forging

4.2.1

The sprue and dead head of steel ingot shall have adequate cut-off quantity so as to ensure that the forging is free from injurious defects like shrinkage cavity and excessive segregation.

4.2.2

The forging press shall be provided with sufficient capability so as to ensure the forging penetration of the whole forging section during forging.

4.3 Heat treatment

At the completion of forging for forgings, normalizing and tempering or quenching and tempering shall be conducted by the supplier so as to ensure the even texture and performance of the forgings, especially the better hardness uniformity of thrust runner surface.

4.4 Rough machining

After the forging is subject to heat treatment, the supplier shall reserve appropriate allowance for rough machining according to the order drawing.

4.5 Stress relief treatment