Effect of Cryogenic Treatment on the Mechanical Properties of 18Ni-300 Grade Maraging Steel Built Using the Direct Metal Laser Sintering (DMLS) Technology

2016 ◽  
Vol 719 ◽  
pp. 114-121 ◽  
Author(s):  
C.A. Jagadish ◽  
Nadig Priyanka
Keyword(s):  
Mechanical Properties ◽  
Maraging Steel ◽  
Cryogenic Treatment ◽  
High Strength ◽  
Laser Sintering ◽  
Pressure Vessels ◽  
Layer By Layer ◽  
Direct Metal Laser Sintering ◽  
Maraging Steels ◽  
High Intensity Laser

Maraging steels belong to the class of steels that are found to have a unique combination of ultra-high strength and good fracture toughness, due to which they find uses in critical applications such as aircraft forgings, pressure vessels, missile casings, hydraulic hoses etc. Several studies on the effect of cryogenic treatment on various grades of Tool steels & Maraging steels have shown significant improvements in mechanical properties and dimensional stability.DMLS (Direct Metal Laser Sintering), an additive manufacturing technology, is increasingly becoming popular to build intricate high quality functional parts & rapid prototypes. DMLS technology uses a high intensity laser to build components layer by layer, directly from CAD data without the need for tooling. It is possible to build internal features and passages that are not possible in conventional manufacturing routes. Maraging Steel is used extensively to build functional parts by DMLS process especially for Tool and Die applications. However, very few findings have been reported on the effect of cryogenic treatment on the mechanical properties of Maraging steel built through this route. In this study, effect of cryogenic treatment on Maraging Steel grade 300 built by DMLS process is discussed. Test specimens were built in horizontal and vertical directions to see the effect of build direction on the properties. Half the specimens were given standard DMLS precipitation hardening heat treatment and the rest were given cryogenic treatment in addition to routine thermal treatment. Mechanical properties such as - tensile, impact properties , hardness, & density between the two sets of treatments are reported and discussed. Metallurgical structures are compared and findings are also reported.

Study of Condensate Generated During Direct Metal Laser Sintering

2017 ◽  
Author(s):  
Jagadish Chandra Achinadka
Keyword(s):  
Maraging Steel ◽  
Laser Sintering ◽  
Steel Grade ◽  
Process Efficiency ◽  
Layer By Layer ◽  
Direct Metal Laser Sintering ◽  
Additive Manufacturing Technology ◽  
High Intensity Laser ◽  
Xrd Studies ◽  
Intensity Laser

DMLS (Direct Metal Laser Sintering), an additive manufacturing technology, is increasingly becoming popular to build intricate high quality functional parts & rapid prototypes. DMLS technology uses a high intensity laser to build components layer by layer, directly from metal powder. CAD data is directly converted to part without the need for tooling. It is possible to build internal features and passages that are not possible in conventional manufacturing routes. The process generates significant amount of condensate due to vaporization and suction applied to build chamber. Typically as much as 30% of the weight of powder ends up as condensate. The condensate so generated cannot be directly recycled. This results in significant reduction in profitability and process efficiency. This study pertains to 18% Ni Maraging Steel grade C300, which commonly used in DMLS process. Maraging Steel is used extensively to build functional parts by DMLS process especially for Tool and Die applications. In the present study chemistry, particle size distribution & morphology of the condensate was studied & compared with the powder. Parts were built using condensate and chemical, physical, mechanical, microstructure and XRD studies were done. These properties were compared with properties of parts built using fresh powder. No difficulty was encountered in building parts using condensate. However, hardness and tensile properties were found to be inferior, thus it is not possible to recycle the condensate directly. Present research investigates the cause of difference in these properties.

Influence of post-heat treatment on microstructure, mechanical, and wear properties of maraging steel fabricated using direct metal laser sintering technique

2021 ◽  
pp. 146442072110373
Author(s):  
Anand Kumar Subramaniyan ◽  
Sudarshan Reddy Anigani ◽  
Snehith Mathias ◽  
Akshay Pathania ◽  
Prasad Raghupatruni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Laser Sintering ◽  
Direct Metal Laser Sintering ◽  
Wear Properties ◽  
Post Heat Treatment ◽  
Heat Treated Sample ◽  
Heat Treated ◽  
Treated Sample

The post-heat treatment of direct metal laser sintered parts is expected to have superior mechanical properties. Therefore, the purpose of the present study is to investigate the post-heat treatment effect on the microstructure, mechanical and wear properties of direct metal laser sintering processed maraging steel. Hence, a systematic methodology for microstructural characterization, mechanical properties, and tribological performance evaluation was performed. The microstructural examinations were performed using optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction technique. The micro-hardness and tensile properties were determined. The unidirectional sliding wear test was performed using a pin on disc wear testing machine for three different sliding velocities (0.8, 1.2, and 1.6 m/s) and three different normal loads (5, 10, and 15 N). The present study’s findings establish that the post-heat treatment techniques significantly altered the microstructural morphology and features. The results showed that the heat-treated sample had finer and non-continuous microstructure and more complex intermetallic precipitate phases, leading to higher hardness (∼64%) and higher tensile strength properties (70–80%) compared to the as-printed sample. The unidirectional sliding wear test results showed that the sliding velocity significantly affected frictional and wear characteristics of direct metal laser sintering processed maraging steel. The wear resistance of the heat-treated sample was three times higher than the as-printed sample, particularly at higher sliding velocities. In addition, the lower coefficient of friction values (∼24%) was observed for heat-treated sample compared to as-printed sample at higher sliding velocities. The post-heat treatment aids as an effective method to enhance mechanical properties of direct metal laser sintered parts and qualify them for tribological applications. The results endorse the suitability of the heat-treated direct metal laser sintered maraging steel in practical tool and die applications involving extreme tribological operating conditions such as higher sliding velocities and contact stresses.

scholarly journals High Strength X3NiCoMoTi 18-9-5 Maraging Steel Prepared by Selective Laser Melting from Atomized Powder

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4174 ◽  
Author(s):  
Angelina Strakosova ◽  
Jiří Kubásek ◽  
Alena Michalcová ◽  
Filip Průša ◽  
Dalibor Vojtěch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Selective Laser Melting ◽  
High Strength ◽  
Industrial Applications ◽  
Tensile Yield Strength ◽  
Laser Melting ◽  
Maraging Steels ◽  
3D Printed

Maraging steels are generally characterized by excellent mechanical properties, which make them ideal for various industrial applications. The application field can be further extended by using selective laser melting (SLM) for additive manufacturing of shape complicated products. However, the final mechanical properties are strongly related to the microstructure conditions. The present work studies the effect of heat treatment on the microstructure and mechanical properties of 3D printed samples prepared from powder of high-strength X3NiCoMoTi 18-9-5 maraging steel. It was found that the as-printed material had quite low mechanical properties. After sufficient heat treatment, the hardness of the material increased from 350 to 620 HV0.1 and the tensile yield strength increased from 1000 MPa up to 2000 MPa. In addition, 3% ductility was maintained. This behavior was primarily affected by strong precipitation during processing.

scholarly journals Increasing Mechanical Properties of 3D Printed Samples by Direct Metal Laser Sintering Using Heat Treatment Process

2021 ◽  
Vol 9 (8) ◽  
pp. 821
Author(s):  
Jozef Živčák ◽  
Ema Nováková-Marcinčínová ◽  
Ľudmila Nováková-Marcinčínová ◽  
Tomáš Balint ◽  
Michal Puškár
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Treatment Process ◽  
High Strength ◽  
Steel Powder ◽  
Laser Sintering ◽  
Heat Treatment Process ◽  
Direct Metal Laser Sintering ◽  
Technical Practice ◽  
3D Printed

The paper deals with the evaluation of mechanical properties of 3D-printed samples based on high-strength steel powder system maraging steel using direct metal laser sintering (DMLS), which is currently being put into technical practice. The novelty of this article is that it analyzes mechanical properties of samples both printed and age hardened as well as examining the fracture surfaces. When comparing the manufacturer’s range with our recorded values, samples from Set 1 demonstrated strength ranging from 1110 to ultimate 1140 MPa. Samples from Set 2 showed tensile strength values that were just below average. Our recorded range was from 1920 to ultimate 2000 MPa while the manufacturer reported a range from 1950 to 2150 MPa. The tensile strength was in the range from 841 to ultimate 852 MPa in Set 1, and from 1110 to ultimate 1130 MPa in Set 2.

Heat Treatment of High-Strength 3D-Printed Maraging Steel

2020 ◽  
Vol 403 ◽  
pp. 67-73
Author(s):  
Angelina Strakosova ◽  
Dalibor Vojtech ◽  
Drahomír Dvorský
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Precipitation Hardening ◽  
High Strength ◽  
Solution Annealing ◽  
Laser Melting ◽  
Maraging Steels ◽  
Final Microstructure ◽  
3D Printed

Maraging steels are interesting for research after heat treatment, from which name is derived "maraging" – martensite-aging. After solution annealing and precipitation hardening the X3NiMoCoTi 18-9-5 alloy has excellent mechanical properties (tensile strength reaches up to 2000 MPa and hardness is 50-55 HRC), it is ductile and well weldable. The advantage of these materials is the possibility to be manufactured not only by conventional methods but also by modern additive manufacturing (AM) methods. One of which is selective laser melting (SLM). In this paper, the influence of heat treatment on the final microstructure and mechanical properties of the 3D-printed X3NiMoCoTi 18-9-5 maraging steel is investigated.

Microstructure of resistance spot welding of maraging steels

1990 ◽  
Vol 48 (4) ◽  
pp. 900-901
Author(s):  
I. Neuman ◽  
S.F. Dirnfeld ◽  
I. Minkoff
Keyword(s):  
Maraging Steel ◽  
Spot Welding ◽  
Lath Martensite ◽  
Base Material ◽  
Aging Treatment ◽  
High Strength ◽  
Maraging Steels ◽  
Heat Treated ◽  
Current Cycle ◽  
Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

Comparison of Microstructure and Mechanical Properties of Additively Manufactured and Conventional Maraging Steel

2020 ◽  
Vol 405 ◽  
pp. 133-138
Author(s):  
Ludmila Kučerová ◽  
Andrea Jandová ◽  
Ivana Zetková
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Precipitation Hardening ◽  
High Strength ◽  
Hardness Measurement ◽  
Nickel Steel ◽  
Heat Treated ◽  
Good Material ◽  
Iron Nickel

Maraging steel is an iron-nickel steel alloy, which achieves very good material properties like high toughness, hardness, good weldability, high strength and dimensional stability during heat treatment. In this work, maraging steel 18Ni-300 was manufactured by selective laser melting. It is a method of additive manufacturing (AM) technology, which produces prototypes and functional parts. Sample of additively manufactured and conventional steel with the same chemical composition were tested after in three different states – heat treated (as-built/as-received), solution annealed and precipitation hardened. Resulting microstructures were analysed by light and scanning electron microscopy and mechanical properties were obtained by hardness measurement and tensile test. Cellular martensitic microstructures were observed in additively manufactured samples and conventional maraging steel consisted of lath martensitic microstructures. Very similar mechanical properties were obtained for both steels after the application of the same heat treatment. Ultimate tensile strengths reached 839 – 900 MPa for samples without heat treatment and heat treated by solution annealing, the samples after precipitation hardening had tensile strengths of 1577 – 1711 MPa.

scholarly journals Mechanical properties comparison of Ti6Al4V produced by different technologies under static load conditions

2019 ◽  
Vol 290 ◽  
pp. 08010
Author(s):  
Karolina Karolewska ◽  
Bogdan Ligaj
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Ti6al4v Alloy ◽  
Direct Metal Laser Sintering ◽  
Static Tests ◽  
Rolling Method ◽  
Manufacturing Techniques ◽  
Materials Used

The most commonly used technology among the additive manufacturing is Direct Metal Laser Sintering (DMLS). This process is based on selective laser sintering (SLS). The method gained its popularity due to the possibility of producing metal parts of any geometry, which would be difficult or impossible to obtain by the use of conventional manufacturing techniques. Materials used in the elements manufacturing process are: titanium alloys (e.g. Ti6Al4V), aluminium alloy AlSi10Mg, etc. Elements printed from Ti6Al4V titanium alloy find their application in many industries. Details produced by additive technology are often used in medicine as skeletal, and dental implants. Another example of the DMLS elements use is the aerospace industry. In this area, the additive manufacturing technology produces, i.a. parts of turbines. In addition to the aerospace and medical industries, DMLS technology is also used in motorsport for exhaust pipes or the gearbox parts. The research objects are samples for static tests. These samples were made of Ti6Al4V alloy by the DMLS method and the rolling method from a drawn rod. The aim of the paper is the mechanical properties comparative analysis of the Ti6Al4V alloy produced by the DMLS method under static loading conditions and microstructure analysis of this material.

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