<p>Steel 17-7PH is austenitic-martensitic steel with high strength, hardness, and resistance to creep, and<br />corrosion. It is designed for aerospace components, but can also be used for other applications that require<br />high strength and corrosion resistance, as well as leaf springs for operation at temperatures up to 316 &deg;C. It<br />can be used in a solution-treated or heat-treated state to obtain a wide range of property values. This<br />paperwork shows that modification of the contents of alloying elements with a narrower interval of Cr, Ni,<br />and Al can be obtained from austenitic-martensitic steel 17-7PH which by, a subsequent heat treatment,<br />can have values of mechanical and chemical properties required for components of an automotive engine.<br />Chromium is an alphagenic alloying element that stabilizes the ferrite region, nickel is a gammagenic<br />alloying element that stabilizes austenite and gives these steels good strength and toughness, even at low<br />temperatures and aluminum increases corrosion resistance in low-carbon corrosion-resistant steels<br />Research has determined the most suitable interval of Cr, Ni, and Al, which in combination with the<br />cryogenic heat treatment RH950 at -50 &deg;C gives the mechanical and chemical properties that meet the<br />requirements for steel with standard chemical composition.</p>

<p>More recently modified stainless steels have been used to produce various structural elements that work in complex operating conditions. Stainless steel X8CrNiS18-9 (standard EN 10088-3) is the most commonly used from the group of austenitic stainless steel in terms of machinability. This steel has high mechanical and working properties thanks to a complex alloying, primarily with elements such as chromium and nickel. The content of sulphur present in the steel from 0.15 to 0.35% improves machinability. However, sulphur at the same time decreases the mechanical properties, particularly toughness. In steel, tellurium stabilizes carbides and reduces the microporosity of the structure. Also, tellurium is now recognized as a powerful sulphur modifier as well as a machinability additive when used in combination with lead and sulphur. This work aims to determine the influence of tellurium on the machinability, corrosion resistance and mechanical properties of the mentioned steel.</p>

Additional strengthening of superalloy N07080 described in this work was achieved by warm rolling. Control of the ratio of strength and ductile properties of the superalloy is possible by appropriate selection of the amount of warm deformation and the appropriate selection of the partial recrystallization temperature. In addition, recrystallization annealing makes it possible to equalize the grain size across the cross section of the warm rolled bars, which before recrystallization differ significantly in size in the central and peripheral parts of the bars.

Magnesium based materials are considered promising biodegradable metals for orthopedic bone implant applications as they exhibit similar density and elastic modulus to that of bone, biodegradability, and excellent osteogenic properties. The use of Mg based biomaterials eliminates the limitations of currently used implant materials such as stress shielding and the need for the second surgery. Recently, the development of Mg-based implants has attracted significant attention. Additive manufacturing is one of the effective techniques to develop Mg based implants. Additive manufacturing which could be named 3D printing is a transformative and rapid method of producing industrial parts with in the acceptable dimensional range. Therefore, recent investigations have tried to apply this method for the development of Mg-based implants. This state-of-the-art review focuses on the additive manufacturing of Mg biodegradable materials and their in-vitro corrosion and degradation, and mechanical properties. The future directions to develop Mg biodegradable materials are reported through summarization of current achievements.

Magnesium has little resistance to corrosion and therefore its production and use are quite limited. The problem of corrosion associated with these alloys has been alleviated to some extent by the advantages obtained from fine coatings. An additional dense barrier against corrosion is created, using coatings obtained from sol-gel. As an alternative for Cr-based conversion coatings, rare-earth elements-based ones are been increasingly investigated for Mg and its alloys due to being eco-friendly. Because of chemical inertness, low friction, and high hardness, diamond-like carbon (DLC) coatings have exhibited the best protection for Mg and its alloys. In this review, we shed light on recent advancements in novel coatings for Mg alloys including hybrid, rare-earth conversion, composite polymeric (polymer composite is a multi-phase material in which reinforcing fillers are integrated with a polymer matrix), and DLC coatings.

Precipitation hardening stainless steel 17-7PH with modified chemical composition was heat treated by modified RH950 condition. In this paper is presented the results of tests of microstructure and mechanical properties of precipitation hardened stainless steel 17-7PH with modified chemical composition, heat treated in modificated RH950 conditions. Regression analysis showed which variables are statistically significant in predicting the value of mechanical properties of the steel 17-7PH chemically modified composition.