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.

Development of Pb-Free Austenitic Stainless Steels

2013 ◽  
Vol 791-793 ◽  
pp. 486-489
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv
Keyword(s):  
Mechanical Properties ◽  
Life Cycle Assessment ◽  
Rare Earth ◽  
Life Cycle ◽  
Rare Earths ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Total Elongation ◽  
Re Elements ◽  
Better Than

Pb-free austenitic stainless steels were investigated by adding sulfur, rare earth (Re) elements and bismuth. The metallurgical properties, machinability and mechanical properties of both steels were examined. The results show that a significant amount of grey, spindle shaped inclusions were discovered in austenitic stainless steels, and they should belong to MnS inclusions containing bismuth element and rare earths oxide. The addition of S, Bi and Re to austenitic stainless steels improved the machinability. The machinability of steel B is better than that of steel A in a way. The mechanical properties of steel B are better than those of steel A, especially total elongation owing to the presence of rare earth elements. From the viewpoint of life cycle assessment, it is proposed that the development of Pb-free austenitic stainless steels containing S, Bi and Re is desirable.

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.

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 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.

scholarly journals Effect of Neutron Irradiation on the Mechanical Properties, Swelling and Creep of Austenitic Stainless Steels

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2622
Author(s):  
Malcolm Griffiths
Keyword(s):  
Mechanical Properties ◽  
Stainless Steels ◽  
Dimensional Stability ◽  
Operating Experience ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Gas Production ◽  
Rate Theory ◽  
Fast Reactors ◽  
Internal Structures

Austenitic stainless steels are used for core internal structures in sodium-cooled fast reactors (SFRs) and light-water reactors (LWRs) because of their high strength and retained toughness after irradiation (up to 80 dpa in LWRs), unlike ferritic steels that are embrittled at low doses (<1 dpa). For fast reactors, operating temperatures vary from 400 to 550 °C for the internal structures and up to 650 °C for the fuel cladding. The internal structures of the LWRs operate at temperatures between approximately 270 and 320 °C although some parts can be hotter (more than 400 °C) because of localised nuclear heating. The ongoing operability relies on being able to understand and predict how the mechanical properties and dimensional stability change over extended periods of operation. Test reactor irradiations and power reactor operating experience over more than 50 years has resulted in the accumulation of a large amount of data from which one can assess the effects of irradiation on the properties of austenitic stainless steels. The effect of irradiation on the intrinsic mechanical properties (strength, ductility, toughness, etc.) and dimensional stability derived from in- and out-reactor (post-irradiation) measurements and tests will be described and discussed. The main observations will be assessed using radiation damage and gas production models. Rate theory models will be used to show how the microstructural changes during irradiation affect mechanical properties and dimensional stability.

scholarly journals EVALUATION OF THE METALLURGICAL PARAMETERS EFFECT ON TENSILE PROPERTIES IN AUSTENITIC STAINLESS STEELS

2017 ◽  
Vol 23 (2) ◽  
pp. 111 ◽  
Author(s):  
Andrea Di Schino ◽  
Maria Richetta
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
304 Stainless Steel ◽  
Strengthening Effect ◽  
Regression Equations ◽  
Aisi 304 ◽  
Solid Solution Strengthening ◽  
Cold Rolling And Annealing

<p>Even if relations predicting the mechanical properties on bars of austenitic stainless steels are already available, but no systematic works was carried out in order to predict mechanical properties in after cold rolling and annealing.   The tensile properties of a large number of cold rolled and annealed AISI 304 stainless steel are here correlated with their chemical composition and microstructure. Quantitative effects of various strengthening mechanisms such as grain size, d– ferrite content and solid solution strengthening by both interstitial and substitutional solutes are described. Interstitial solutes have by far the greatest strengthening effect and, among the substitutional solutes, the ferrite – stabilising elements have a greater effect than the austenite – stabilising elements. Regression equations are developed which predict with good accuracy the proof stress and tensile strength in AISI 304 stainless steels.</p>

scholarly journals Rare Earth Elements Enhanced the Oxidation Resistance of Mo-Si-Based Alloys for High Temperature Application: A Review

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1144
Author(s):  
Laihao Yu ◽  
Yingyi Zhang ◽  
Tao Fu ◽  
Jie Wang ◽  
Kunkun Cui ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Rare Earth Elements ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Strengthening Mechanism ◽  
Advanced Materials ◽  
Performance Requirements ◽  
Large Numbers ◽  
The One

Traditional refractory materials such as nickel-based superalloys have been gradually unable to meet the performance requirements of advanced materials. The Mo-Si-based alloy, as a new type of high temperature structural material, has entered the vision of researchers due to its charming high temperature performance characteristics. However, its easy oxidation and even “pesting oxidation” at medium temperatures limit its further applications. In order to solve this problem, researchers have conducted large numbers of experiments and made breakthrough achievements. Based on these research results, the effects of rare earth elements like La, Hf, Ce and Y on the microstructure and oxidation behavior of Mo-Si-based alloys were systematically reviewed in the current work. Meanwhile, this paper also provided an analysis about the strengthening mechanism of rare earth elements on the oxidation behavior for Mo-Si-based alloys after discussing the oxidation process. It is shown that adding rare earth elements, on the one hand, can optimize the microstructure of the alloy, thus promoting the rapid formation of protective SiO2 scale. On the other hand, it can act as a diffusion barrier by producing stable rare earth oxides or additional protective films, which significantly enhances the oxidation resistance of the alloy. Furthermore, the research focus about the oxidation protection of Mo-Si-based alloys in the future was prospected to expand the application field.

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