Due to its versatility, there are a wide range of stainless steel fabricating techniques. It may be helpful to review some of the processes involved in order to better understand the benefits and disadvantages of the different types of stainless steel fabrication.
Although it has relatively high strength and work hardening rates, stainless steel is malleable enough to be bent, folded, machined, welded, deep drawn, or spun. This guide will focus on three common stainless steel fabricating processes: work hardening, machining, and welding.
Work Hardening with Stainless Steel
Work hardening is the process of strengthening material through deformation. Relative to other varieties of steel, stainless steel work hardens quickly, although the exact rate depends on the specific grade of the alloy. The austenitic family of stainless steel, for example, has a hardening rate slightly higher than that of carbon steel and is a frequently used grade series in fabrication processes.
It is also helpful to match the steel grade with a work hardening treatment that is well-suited for it. Since austenitic stainless steel can usually be hardened only through cold working, a thermal treatment process would be better applied to other grades, such as those in the martensitic family.
Work Hardening Rates of Stainless Steel
Since ferritic stainless steels yield lower work hardening rates, austenitic and martensitic stainless steels are the series that benefit most from work hardening applications. In some instances, austenitic stainless steel can be cold worked up to 1,000 MPa, although the maximum is typically in the 800 MPa range. When cold drawn, stainless steel may reach tensile properties of 2,000 MPa or greater, but such high strength levels are usually limited to fine wire sizes. Size is a concern due in part to the quick work hardening rate of stainless steel, which yields diminishing tensile strengthening at the core of a wire as its diameter increases.
A fast work hardening rate provides certain benefits, as well. For example, stainless steel’s hardening rate renders the alloy effective in projects that require high strength and corrosion resistance. Common applications include the manufacturing of nuts and bolts, machine parts, cryogenic machinery and hospital equipment. The martensitic group, in particular, displays the highest levels of hardness and corrosion resistance among the stainless steel categories, making it a popular alloy for the production of tools, valve parts, bearings, and cutlery.
Read more: Stainless Steel Fabricating Processes