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IN ANY survey of stainless steel applications it is soon apparent that in the vast majority of cases it is the corrosion resistance of the material which is the deciding factor in its selection. Appearance, non‐toxicity, retention of strength at high and low temperatures, and ease of fabrication are all important in varying degrees, but the widespread applications of stainless steel— a material which celebrated its first half‐century only a few years ago—follow principally from its inherent ‘stainless’ properties which confer a remarkable degree of resistance to attack in a wide variety of environments.

States that duplex (austenitic/ferritic) stainless steels offer properties of interest and a cost‐effective material selection solution for plant and equipment in the pulp and paper industry. Reviews characteristics of duplex steels leading to successful long‐term applications of 22 Cr duplex and a copper containing 25 Cr super duplex stainless steel. Concludes that, applied correctly, two‐phase stainless steels can provide long‐term reliable maintenance‐free service in many pulp and paper plant environments.

The great superiority of stainless‐steel alloys over iron, although they contain a high percentage of it, is that they do not rust when exposed to water and air and also resist corrosion when used with many chemicals. As a construction material for apparatus, stainless steel is widely used in chemical industry. Several of the alloys have many interesting mechanical properties and can easily be machined and welded. Thanks to these properties, the production of stainless steels during the last 20 years has increased more than tenfold. This article is adapted by the author from his book, Notions Pratiques de Génie Chimique, Georg éditeur, Geneva.

Until the strike broke out at the mines of the International Nickel Company in Canada, in July 1969, there had been relative stability in the stainless steel market in this country for many years. Before the Iron & Steel Board was abolished, its price list had been accepted as the ruling one; later, after the British Steel Corporation was formed in 1967, its list was used. However, the nickel strike put an end to all that. By the time the strike ended the price of nickel had reached, momentarily, the dizzy height of £7,000/ton. Mills were quoting 40 week deliveries for stainless steel, often tongue in cheek, as they waited for the strike to end and raw material prices to come down.

Introduction To the corrosion engineer, the various types of stainless steel are as important as the bible is to a vicar. Corrosion technology never stands still, and developments in both the composition and application of stainless steel are continually being made to keep abreast of the demand to deal with the ever increasing complexity of situations that present themselves.

Stainless steels are very unique in that they offer a wide range and combination of resistance to corrosion, resistance to oxidation at high temperature and good mechanical properties at room temperature. With rapid industrialization all over the world, these very properties have led to extensive use of stainless steels in different industries. Austenitic stainless steels containing molybdenum exhibit corrosion resistance in both sulphuric acid and nitric acid. Stainless steel undergoes severe attack in sulphuric acid having concentrations in the range of 20‐85 per cent, whereas they are immune to nitric acid in any concentration. However, sensitized stainless steels are prone to intergranular attack in acids, even in nitric acid. Further, the attack is aggravated in the presence of aggressive ions. Study of the behaviour of stainless steels in a mixture of acids (nitric and sulphuric acid) is lacking in the literature. This paper, therefore, discusses the performance of AISI‐316 and 316‐L in sulphuric acid and nitric acid and a mixture thereof at room temperature. It is observed that the steels are quite resistant to sulphuric acid and nitric acid, but in the acid mixture they are not so resistant, especially in AISI‐316 SS in respect of corrosion resistance, even in acid mixture containing C1^‐ and Cu⁺⁺ ions.

The use of materials in marine environments has traditionally been associated with ships. However, in recent years, important new industries have grown up which present new material problems. Notable amongst such industries are offshore oil production and desalination (production of fresh water from seawater). Also, requirements for large amounts of cooling water by modern industry have often resulted in siting of plants by the ocean, particularly in arid areas such as the Middle East. This has increased interest in the use of materials for handling seawater.

Stainless‐steel Tubes in Condenser. Power companies, using a non‐ferrous metal, replaced tubing in their steam condensers after five to eight years' service at Elrama, on the Monongahela River, eastern U.S.A. Two years ago, one of the companies re‐tubed with stainless steel. Now, the new No. 4 unit of the Duquesne Light Co. which will be completed next month includes a condenser containing 15,412 Type 304 stainless‐steel tubes, a large portion of which were supplied by Allegheny Ludlum Steel Corporation, each having a life expectancy of 30 years. The overall condensing surface area is 105,000 sq. ft. Exhaust steam from the low‐pressure turbine is condensed and returned to the boiler where it is converted into high — pressure steam to run the 165,000‐kw. turbine generator. Approximately 90,000 gal./min. of river water are pumped through the two‐pass condenser, which is capable of condensing 850,000 lb./hr. An electronic tube roller is used to seal the ends of the tubes in tube sheets with stainless steel.

Stainless steel grades on show. Exhibiting for the first time at Offshore Europe '85, to be held on 10–13 September 1985 at the Aberdeen Exhibition and Conference Centre, on Stand 1E5/23 Avesta Johnson Stainless Ltd will be presenting the Avesta range of stainless steel products, including welded stainless steel pipe and tube from AST.

This study aims to demonstrate the application of Lean Six Sigma (LSS) at a stainless steel manufacturer in Türkiye for yield improvement.

A qualitative approach consisting of a single descriptive case study was adopted. Both primary and secondary sources were used. The interviews were conducted with the Six Sigma team. In addition, an in-depth review of the project documents was conducted. The “define, measure, analyze, improve and control (DMAIC)” phases were explained by examining the tables, facts and figures. The company’s downgraded rate owing to defective materials was 0.21%. Root causes were detected in the tension unit, carpet cleaning, coating unit, film surface and cleaning of the rolls. Therefore, improvements were taken accordingly.

The rolled throughput yield was 99.05%, and the defect rate was reduced to 0.08% after implementing LSS, which provided statistically proven results and a direct reflection on customer satisfaction.

To the best of the author’s knowledge, this is the first case study examining the application of LSS to improve the yield of a medium-sized stainless steel company in Türkiye.