Stainless steel forging is a method of metal forming by which the metal is heated to a temperature that allows it to be malleable (for stainless steel the forging temperature is 2003ºF if magnetic and 2102 ºF if nonmagnetic) and then molded or shaped by applying force in the form of hammer blows or a press.
Stainless steels work well in terms of forgeability, but because they remain strong at forging temperatures, they often require more hammer force and/or hammer blows than other alloys.
The forging of stainless steels is used to make a number of manufactured parts for a variety of industries because of its exceptional resistance to corrosion. Due to its wide availability in most markets as well as its high level of strength and ductility, stainless steel is considered a great option for cost effective metal fabrication.
There are three main types of forged stainless steel available on the market today. The first is referred to as drawn out stainless steel and is defined by a lengthening while the width is decreased. Upset stainless steel can be seen as the opposite of drawn out steel where the width is increased and the length decreased.
Squeezed in stainless steel is created by a closed die process that allows for multi-directional flow and results in a solid, compact shape. Stainless steel forging offers benefits including increased ductility, high levels of formability, increased grain uniformity and strength, prevention of strain hardening and a decrease in chemical incongruities.
In order to get the most out of the process, it is also important to note the possibility of variations or warping that could occur during the cooling process as well as the possibility of atmospheric reactions with the metal, and to take measures to prevent these.
Forged stainless steel is used in a wide range of applications such as consumer, industrial, automotive, aerospace, medical, ship-building, hardware, locomotive, oil and gas, hand tools, and especially for the manufacturing of products that must have substantial durability as well as a high resistance to corrosion.
It is a protective oxide layer that aids in corrosion resistance and its durability is attributed to its ability to resist pitting, stress cracking, deformation, crevice corrosion, and other structural failures that often shorten the working life of a forged part. The open die forging process allows the stainless steel to maintain its internal grain, which results in parts that are often much stronger than parts created though the machining or casting processes.