Low Environmental Impact Machining Processes of Free Cutting Austenitic Stainless Steels without Lead Addition

2012 ◽  
Vol 512-515 ◽  
pp. 1923-1926
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv
Keyword(s):  
Stainless Steel ◽  
Performance Improvement ◽  
Stainless Steels ◽  
Environmental Performance ◽  
Austenitic Stainless Steels ◽  
Machining Processes ◽  
Machine Operators ◽  
Chip Breakage ◽  
Lead Addition ◽  
Better Than

Environmental protection is a growing concern for many industries today. This paper shows manufacturing environmental performance improvement for free cutting steel products. Inclusions have the characteristics of sulfur and bismuth in free cutting austenitic stainless steels without lead addition. Machinable additives lead to improved chip breakage, and thus reduced tool wear. The machinability of free cutting austenitic stainless steels without lead addition is much better than that of conventional austenitic stainless steel. Bismuth can replace lead because lead is a harmful factor for environment and machine operators' health. The reduction of environmentally harmful substances such as lead was performed. A feasible combination of free-cutting additives should yield a stainless steel product with acceptable machining and mechanical properties.

Effect of Rare Earth Elements on Machining Characteristics of Austenitic Stainless Steels without Lead Addition

2013 ◽  
Vol 377 ◽  
pp. 128-132
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv ◽  
Shao Pu Kang ◽  
Zhen Zheng
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Large Numbers ◽  
Machining Characteristics ◽  
Lead Addition ◽  
Cutting Speeds ◽  
Better Than

Rare earth elements (REE) are harmless for human health. REE addition contributes to the improvement of the machinability of the steels. In the present paper, machining characteristics of austenitic stainless steels without lead addition were investigated by adding free-machining elements, such as sulfur, REE and bismuth. The results have shown that large numbers of rounded, globular shaped inclusions were obtained for both steels. The machinability of steel B is better than that of steel A, and the cutting forces of steel B are lower than those of steel A at various cutting speeds. Lead can be substituted by REE and bismuth in free machinable austenitic stainless steels. REE significantly affects machining characteristics of austenitic stainless steels without lead addition. The mechanical properties of both steels were similar, and their fracture exhibited ductile characteristics. Satisfactory machinability and mechanical properties can be obtained for both steels.

Investigations on Low Environmental Impact Machining Processes of Free Cutting Austenitic Stainless Steels

2013 ◽  
Vol 377 ◽  
pp. 112-116 ◽  
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv ◽  
Zhen Zheng ◽  
Shao Pu Kang
Keyword(s):  
Mechanical Properties ◽  
Environmental Impact ◽  
Rare Earths ◽  
Stainless Steels ◽  
Manganese Sulfide ◽  
Austenitic Stainless Steels ◽  
Chip Morphology ◽  
Machining Processes ◽  
Soft Phase ◽  
Better Than

In the present paper, sulfur, RE (rare earth) and bismuth were added to an austenite stainless steel. Low environmental impact machining processes of free cutting austenitic stainless steels was investigated by machinability testing. The results show that a significant amount of grey and dispersed inclusions were found in steel B. The inclusions are typical sulfide inclusions, and bismuth element is attached to double end of manganese sulfide inclusions. Some inclusions exhibit globular shape due to the presence of rare earths elements in steel B. Chip morphology was improved in steel B under the same turning conditions. The machinability of steel B is much better than that of steel A. This is attributed to the presence of free-cutting additives of sulfur, RE and bismuth in the austenitic stainless steels. Satisfactory mechanical properties were also obtained under the conditions of our experiments. The reasons why satisfactory mechanical properties were obtained may lie in that the sulfides and bismuth are soft phase, and the presence of rare earths elements contributes to the improvement of the toughness of the austenitic stainless steels.

Study on the Machinability of Free Cutting Non-Lead Austenitic Stainless Steels

2012 ◽  
Vol 430-432 ◽  
pp. 306-309 ◽  
Author(s):  
Di Wu ◽  
Zhuang Li
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Crack Nucleation ◽  
Austenitic Stainless Steels ◽  
Distinct Advantage ◽  
Metallurgical Properties ◽  
Better Than

In this paper, a new non-lead machinable austenitic stainless steel was investigated. The metallurgical properties, machinability and mechanical properties of the developed alloy were compared with those of the conventional austenitic stainless steel 321. The results have shown that the presence of machinable additives, such as sulfur, copper and bismuth, etc. contributes to the improvement of the machinability of austenitic stainless steel, because the inclusions are something like internal notches causing crack nucleation and facilitating rupture. Bismuth has a distinct advantage over lead. The machinability of the austenitic stainless steels with free-cutting additives is much better than that of austenitic stainless steel 321. The mechanical properties of the free cutting austenitic stainless steel are similar to those of 321 although the former are slightly lower than those of the latter.

ALZ 410S

Alloy Digest ◽  
2001 ◽  
Vol 50 (9) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Mild Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Chromium Content ◽  
Austenitic Stainless Steels ◽  
Oxidation And Corrosion ◽  
Better Than

Abstract ALZ 410S is a ferritic stainless steel with approximately 13% Cr, and belongs with the lowest-alloyed stainless steels. The chromium content has been chosen to be on the threshold of formation of the passivation layer. It has an oxidation and corrosion resistance that is much better than that of mild steel, but cannot be compared with the corrosion resistance of the austenitic stainless steels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on joining. Filing Code: SS-830. Producer or source: ALZ nv.

ALZ 316

Alloy Digest ◽  
1999 ◽  
Vol 48 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Heat Treating

Abstract ALZ 316 is an austenitic stainless steel with good formability, corrosion resistance, toughness, and mechanical properties. It is the basic grade of the stainless steels, containing 2 to 3% molybdenum. After the 304 series, the molybdenum-containing stainless steels are the most widely used austenitic stainless steels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-756. Producer or source: ALZ nv.

ALLOY 0Cr25Ni6Mo3CuN

Alloy Digest ◽  
1998 ◽  
Vol 47 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Temperature Performance ◽  
Steel Research ◽  
Oil Refinement

Abstract ALLOY 0Cr25Ni6Mo3CuN is one of four grades of duplex stainless steel that were developed and have found wide applications in China since 1980. In oil refinement and the petrochemical processing industries, they have substituted for austenitic stainless steels in many types of equipment, valves, and pump parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming and joining. Filing Code: SS-706. Producer or source: Central Iron & Steel Research Institute.

CARTECH 347

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Austenitic Stainless Steels ◽  
Heat Treating ◽  
Intermittent Heating ◽  
Technology Corporation ◽  
Carpenter Technology Corporation

Abstract CarTech 347 is a niobium+tantalum stabilized austenitic stainless steel. Like Type 321 austenitic stainless steel, it has superior intergranular corrosion resistance as compared to typical 18-8 austenitic stainless steels. Since niobium and tantalum have stronger affinity for carbon than chromium, carbides of those elements tend to precipitate randomly within the grains instead of forming continuous patterns at the grain boundaries. CarTech 347 should be considered for applications requiring intermittent heating between 425 and 900 °C (800 and 1650 °F). This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1339. Producer or source: Carpenter Technology Corporation.

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

Developing New Cast Austenitic Stainless Steels With Improved High-Temperature Creep Resistance

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Michael J. Pollard
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Creep Strength ◽  
Stainless Steels ◽  
Creep Resistance ◽  
Austenitic Stainless Steels ◽  
Creep Rupture ◽  
Particulate Filter ◽  
Alloy Development ◽  
Wide Range

Oak Ridge National Laboratory and Caterpillar (CAT) have recently developed a new cast austenitic stainless steel, CF8C-Plus, for a wide range of high-temperature applications, including diesel exhaust components and turbine casings. The creep-rupture life of the new CF8C-Plus is over ten times greater than that of the standard cast CF8C stainless steel, and the creep-rupture strength is about 50–70% greater. Another variant, CF8C-Plus Cu/W, has been developed with even more creep strength at 750–850°C. The creep strength of these new cast austenitic stainless steels is close to that of wrought Ni-based superalloys such as 617. CF8C-Plus steel was developed in about 1.5 years using an “engineered microstructure” alloy development approach, which produces creep resistance based on the formation of stable nanocarbides (NbC), and resistance to the formation of deleterious intermetallics (sigma, Laves) during aging or service. The first commercial trial heats (227.5 kg or 500 lb) of CF8C-Plus steel were produced in 2002, and to date, over 27,215 kg (300 tons) have been produced, including various commercial component trials, but mainly for the commercial production of the Caterpillar regeneration system (CRS). The CRS application is a burner housing for the on-highway heavy-duty diesel engines that begins the process to burn-off particulates trapped in the ceramic diesel particulate filter (DPF). The CRS/DPF technology was required to meet the new more stringent emissions regulations in January, 2007, and subjects the CRS to frequent and severe thermal cycling. To date, all CF8C-Plus steel CRS units have performed successfully. The status of testing for other commercial applications of CF8C-Plus steel is also summarized.

Corrosion Resistance of Nickel-Free Austenitic Stainless Steels and their Nanocomposites with Hydroxyapatite in Ringer's Solution

2011 ◽  
Vol 674 ◽  
pp. 159-163 ◽  
Author(s):  
Maciej Tulinski ◽  
Mieczyslaw Jurczyk
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Mechanical Alloying ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Orthopedic Implants ◽  
Corrosion Current ◽  
Similar Process ◽  
Distinct Advantage ◽  
Ion Release

In this work Ni-free austenitic stainless steels with nanostructure and their nanocomposites were synthesized by mechanical alloying (MA), heat treatment and nitriding of elemental microcrystalline Fe, Cr, Mn and Mo powders with addition of hydroxyapatite (HA). Microhardness and corrosion tests' results of obtained materials are presented. Mechanical alloying and nitriding are very effective technologies to improve the corrosion resistance of stainless steel. Decreasing the corrosion current density is a distinct advantage for prevention of ion release and it leads to better cytocompatibility. Similar process in case of nanocomposites of stainless steel with hydroxyapatite helps achieve even better mechanical properties and corrosion resistance. Hence nanocrystalline nickel-free stainless steels and nickel-free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants, e.g. orthopedic implants.

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