Stainless Steel 101

High Performance Alloys for Architecture



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Michael Mulhern


TriPyramid Structures



This paper presents a summary of the industry advances beyond T304 and T316 austenitic stainless steels. The greater availability of precipitation hardening and duplex stainless steels has increased the material pallet for designers and engineers. However, these materials vary widely in price and applicable fabrication practices. A working knowledge of stainless steel characteristics is required for the successful use of these materials.

The successful integration of stainless steel for architectural elements is challenging. There are well documented cost savings in maintenance with corrosion resistant materials when looked at over a building’s full lifecycle. High performance stainless steel alloys afford greater strength than traditional building materials. This results in aesthetic advantages to the designer, however the higher costs and difficulties in fabrication present challenges for the building team. New stainless alloys have been developed for use in other industries. Some of these alloys have advanced material properties that make them applicable in the construction marketplace. In order for these materials to be properly utilized, it is important to understand their benefits and drawbacks.

Building construction is not a primary consumer of stainless steel in the global marketplace. The metallurgical innovation going on today can be broadly classified as follows: the transportation sector desires stainless steel materials with higher strength at lower prices. The development of light, more fuel-efficient vehicles is responsible for innovations such as lean duplex stainless steels (high strength, lower cost). The oil and gas industry continues to press for materials that are extremely corrosion resistant for sour wells. The aerospace sector requires alloys that maintain their strength and corrosion resistance at very high temperatures. Our goal is to provide the reader with a better understanding of how to benefit from these innovations and illustrate the pitfalls/inefficiencies of simply specifying “stainless steel” in bidding documentation.


In 1928 when the Chrysler building was built Krupp Steel in Germany had just begun to produce small amounts of non-rusting stainless steel they called “Nirosta.” The steel was developed

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Section 1: Stainless Steel Basics

Stainless steels are a mixture of iron and alloying materials such as carbon, nickel, chrome, molybdenum, copper, nitrogen etc. The ratio of these alloying elements changes the properties and the

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Section 2: Properties and Processes Differnentiate the Stainless Grades

Corrosion resistance: Stainless steels gain their corrosion resistance from a passive film that develops in an oxidizing environment. This film develops quickly after the stainless steel has been cut or

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Section 3: Stainless Types

There are many references available to find the chemical and mechanical properties of all stainless steels. One good guide is the Outokumpu Handbook of Stainless Steel. However most of the

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The demand for stainless steel in global industry has led to the development of new alloys. While most of these are not widely seen in the building arena, some of

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Rights and Permissions

Cobb, Harold. The History of Stainless Steel. ASM International, 2010.

Outokumpu. “Handbook of Stainless Steel.” [HSS], 2013.

Bhadeshia, H.K. “Interpretation of the Microstructure of Steels.” University of Cambridge, 2008.

Outokumpu. “The Outokumpu Corrosion Handbook” [OCH], 2010.

Houska, Catherine. “Stainless Steels in Architecture, Building and Construction: Guidelines for corrosion protection.” Nickel Institute Reference Book Series No 11.024, 2014.

Bhaduri, A.K, S. Sujith, G.Srinivasan, T.P.S. Gill, S.L. Mann. “Optimized Postweld Heat Treatment Procedures for 17-4PH Stainless Steels.” Welding Research Supplement, 1995.

Honess, Colin, Alan Harris. “Importance of Surface Finish in the Design of Stainless Steel.” Stainless Steel Industry, 2005.

BSSA. “Stress relieving heat treatments for austenitic stainless steels.” [AST] / (accessed 9/30/2017)

Armco Steel. “17-4PH Product Data Bulletin.” BS-82. 1986

BSSA. “Duplex Stainless Steels- A simplified Guide.” [DSG] / (accessed 9/30/2017)

IMOA. “Practical Guidelines for fabrication of Duplex Stainless Steels.” International Molybdenum Association, 2009.

Grazinio, Ubertalli, Dinato Firrao, Gianmarco Tiveri. “Characterizationof Welded Joints (MIG and SAW) on LDX 2101.” Procedia Engineering, Volume 109, 2015.