1 Preparation before forging

(1) Billet selection

Select appropriate billets according to the final product shape and performance requirements of stainless steel. Billets can be bars, plates or ingots. For parts with complex shapes, ingots may need to be selected for forging to ensure the uniformity of the material. At the same time, the size of the billet should be considered, and sufficient processing allowance should be left. The allowance generally ranges from a few millimeters to more than ten millimeters, depending on the size and precision requirements of the parts.

(2) Heating equipment

Stainless steel forging requires appropriate heating equipment. Commonly used ones are resistance furnaces and gas furnaces. Resistance furnaces have accurate heating temperature control and high thermal efficiency, which can make the stainless steel billet heated evenly. Gas furnaces have fast heating speed, but the temperature control is relatively complicated. Control of heating temperature is crucial for stainless steel forging, because different types of stainless steel have different starting and ending forging temperature ranges. For example, the starting forging temperature of austenitic stainless steel is generally around 1150-1200℃, and the ending forging temperature is not less than 900℃.

2 Forging process

(1) Forging methods

It includes free forging and die forging. Free forging is highly flexible and is suitable for small-batch production of single pieces or large parts with simple shapes. Forging workers gradually shape the blank by operating forging tools such as air hammers and steam-air hammers. Die forging uses a die to shape the blank, which has high production efficiency and is suitable for mass production of parts with complex shapes and high dimensional accuracy requirements. For example, stainless steel connecting rods for automobile engines are usually produced by die forging.

(2) Selection of forging ratio

The forging ratio is an indicator of the degr