High performance stainless steel via powder metallurgy hot isostatic pressing

1997 ◽  
Vol 13 (12) ◽  
pp. 1027-1032 ◽  
Author(s):  
G. Appa Rao ◽  
Mahendra Kumar
Keyword(s):  
Stainless Steel ◽  
Powder Metallurgy ◽  
High Performance ◽  
Hot Isostatic Pressing ◽  
Isostatic Pressing

A Novel Forming Process for Powder Metallurgy of Superalloys

2014 ◽  
Vol 622-623 ◽  
pp. 833-839 ◽  
Author(s):  
Qian Bai ◽  
Jian Guo Lin ◽  
Gao Feng Tian ◽  
Daniel S. Balint ◽  
Jin Wen Zou
Keyword(s):  
Powder Metallurgy ◽  
Relative Density ◽  
High Performance ◽  
Low Cost ◽  
Hot Isostatic Pressing ◽  
Hot Extrusion ◽  
Forming Process ◽  
Isostatic Pressing ◽  
Wide Range ◽  
Forming Temperature

Powder metallurgy (PM) of nickel-based superalloys has been used for a wide range of products owing to their excellent special properties in processing and applications. Typical processes for high performance PM superalloys include hot isostatic pressing, hot extrusion and hot isothermal forging. Hot isostatic pressing is normally conducted at a high temperature, by using a low pressure for a long time in a closed vessel, resulting in high cost and low product efficiency. In this paper a novel forming process, i.e. direct powder forging for powder metallurgy of superalloys has been proposed. In this process, the encapsulated and vacuumed powder is heated up to the forming temperature and forged directly to the final shape, by using a high forming load for a very short time. Direct powder forging is a low-cost and energy-saving process compared to conventional PM processes, and in addition, press machines of conventional forging can be used for direct powder forming process. In direct powder forging it is important to control the relative density of the deformed part since the existence of voids could reduce the mechanical strength and fatigue life. In this paper, feasibility tests of direct powder forging are presented. Microstructure, relative density and hardness of the formed specimen were studied.

scholarly journals Evolution of Microstructure and Elements Distribution of Powder Metallurgy Borated Stainless Steel during Hot Isostatic Pressing

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Yanbin Pei ◽  
Xuanhui Qu ◽  
Qilu Ge ◽  
Tiejun Wang
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Powder Metallurgy ◽  
Relative Density ◽  
Hot Isostatic Pressing ◽  
Elemental Distribution ◽  
Isostatic Pressing ◽  
Average Grain Size ◽  
Borated Stainless Steel

prepared by powder metallurgy process incorporating atomization and hot isostatic pressing (HIP) sintering at six different temperatures from 600 to 1160 °C, borated stainless steel (BSS) containing boron content of 1.86 wt% was studied. The phase of BSS, relative density of different temperature, microstructure, elemental distribution, and mechanical properties were tested and analyzed. The phases of the alloy were calculated by the Thermo-Calc (2021a, Thermo-Calc Software, Solna, Sweden) and studied by quantitative X-ray diffraction phase analysis. The distributions of boron, chromium, and iron in grains of the alloy were analyzed by scanning electron microscopy and transmission electron microscope. The grain size distributions and average grain sizes were calculated for the boron-containing phases at 900, 1000, 1100, and 1160 °C, as well as the average grain size of the austenite phase at 700 and 1160 °C. After undergoing HIP sintering at 900, 1000, 1100, and 1160 °C, respectively, the tensile strength and ductility of the alloy were tested, and the fracture surfaces were analyzed. It was found that the alloy consisted of two phases (austenite and boron-containing phase) when HIP sintering temperature was higher than 900 °C, and the relative density of the prepared alloys was higher than 99% when HIP temperature was higher than 1000 °C. According to the boron-containing phase grain size distribution and microstructure analysis, the boron-containing phase precipitated both inside the austenite matrix and at the grain boundaries and its growth mechanism was divided into four steps. The tensile strength and elongation of alloy were up to 776 MPa and 19% respectively when the HIP sintering was at 1000 °C.

scholarly journals Evolution of the Microstructure and Mechanical Properties of a Ti35Nb2Sn Alloy Post-Processed by Hot Isostatic Pressing for Biomedical Applications

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1027
Author(s):  
Joan Lario ◽  
Ángel Vicente ◽  
Vicente Amigó
Keyword(s):  
Powder Metallurgy ◽  
Mechanical Strength ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Phase Changes ◽  
Post Processing ◽  
Isostatic Pressing ◽  
Porosity Reduction ◽  
Processing Step ◽  
Hip Process

The HIP post-processing step is required for developing next generation of advanced powder metallurgy titanium alloys for orthopedic and dental applications. The influence of the hot isostatic pressing (HIP) post-processing step on structural and phase changes, porosity healing, and mechanical strength in a powder metallurgy Ti35Nb2Sn alloy was studied. Powders were pressed at room temperature at 750 MPa, and then sintered at 1350 °C in a vacuum for 3 h. The standard HIP process at 1200 °C and 150 MPa for 3 h was performed to study its effect on a Ti35Nb2Sn powder metallurgy alloy. The influence of the HIP process and cold rate on the density, microstructure, quantity of interstitial elements, mechanical strength, and Young’s modulus was investigated. HIP post-processing for 2 h at 1200 °C and 150 MPa led to greater porosity reduction and a marked retention of the β phase at room temperature. The slow cooling rate during the HIP process affected phase stability, with a large amount of α”-phase precipitate, which decreased the titanium alloy’s yield strength.

scholarly journals Study on the Hot Deformation Characterization of Borated Stainless Steel by Hot Isostatic Pressing

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7110
Author(s):  
Yanbin Pei ◽  
Xuanhui Qu ◽  
Qilu Ge ◽  
Tiejun Wang
Keyword(s):  
Stainless Steel ◽  
Hot Deformation ◽  
True Strain ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Critical Conditions ◽  
True Strain Rate ◽  
Isostatic Pressing ◽  
Different Temperatures ◽  
Borated Stainless Steel

Borated stainless steel (BSS) specimens have a boron content of 1.86 wt%, and are prepared by hot isostatic pressing (HIP) conducted at different temperatures, ranging from 1000 to 1100 °C and a constant true strain rate (0.01, 0.1, 1 and 10 s−1). These tests, with observations and microstructural analysis, have achieved the hot deformation characteristics and mechanisms of BSS. In this research, the activation energy (Q) and Zener–Hollomon parameter (Z) were contrasted against the flow curves: Q = 442.35 kJ/mol. The critical conditions associated with the initiation of dynamic recrystallization (DRX) for BSS were precisely calculated based on the function between the strain hardening rate with the flow stress: at different temperatures from 1000 to 1100 °C: the critical stresses were 146.69–254.77 MPa and the critical strains were 0.022–0.044. The facts show that the boron-containing phase of BSS prevented the onset of DRX, despite the saturated boron in the austenite initiated DRX. The microstructural analysis showed that hot deformation promoted the generation of borides, which differed from the initial microstructure of HIP. The inhomogeneous distribution of elements in the boron-containing phase was caused by hot compression.

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

Development of Ni-base metal matrix composites by powder metallurgy hot isostatic pressing for space applications

2022 ◽  
pp. 103411
Author(s):  
Alessandro Sergi ◽  
Raja H.U. Khan ◽  
Sandeep Irukuvarghula ◽  
Martina Meisnar ◽  
Advenit Makaya ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Metal Matrix Composites ◽  
Base Metal ◽  
Metal Matrix ◽  
Hot Isostatic Pressing ◽  
Matrix Composites ◽  
Space Applications ◽  
Isostatic Pressing

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

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