Effects of Nickel on Structure and Properties of Ferro Superalloy

2011 ◽  
Vol 250-253 ◽  
pp. 733-736
Author(s):  
Hai Tao Wang ◽  
Chang Lu Chen ◽  
Dian Cai Kang
Keyword(s):  
Tensile Strength ◽  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Structure And Properties ◽  
Temperature Oxidation ◽  
Gain Rate ◽  
High Temperature Tensile ◽  
Oxidation Weight Gain ◽  
Weight Gain Rate

The affecting law of nickel on structure and properties of ferro superalloy, which was cast by intermediate frequency induction furnace, were studied by orthogonal experimental method. The tensile strength and oxidation weight gain rate at 1000°C were tested. The matrix microstructure and scale morphologies and composition were studied using scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. It was found that the high temperature tensile strength went up with the increase of nickel by the forming of high temperature strengthening phase of γ’. After 100 hours aging at 1000°C, γ’ phase separated in blocks. Certain content of nickel improved the high temperature oxidation resistance of test alloys, but excess of it caused the higher oxidation weight gain rate and loose structure oxide scales with holes and exfoliating. In considering of high temperature tensile strength and oxidation resistance, the ideal content of nickel in ferro superalloy should be 9wt.%, with which at 1000°C the tensile strength of test alloys mostly exceeded 70MPa, and the average oxidation weight gain rate was only 0.55g.m-2.h-1, reaching the strong oxidation resistance. Such scale was compounded by Cr2O3 and Fe(Ni)Cr2O4 with compact structure, fine and even oxide grains.

Increased High Temperature Oxidation Resistance of Ni20Cr20Fe5Nb1Y2O3 Alloy with Nano-Sized Grains

2005 ◽  
Vol 486-487 ◽  
pp. 109-112 ◽  
Author(s):  
Il Ho Kim ◽  
S.I. Kwun
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Mechanical Alloying ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Tensile Property ◽  
High Temperature Oxidation ◽  
Room Temperature ◽  
Dispersion Strengthening ◽  
Temperature Oxidation

The oxidation and tensile properties of a Ni20Cr20Fe5Nb alloy and a Ni20Cr20Fe 5Nb1Y2O3 alloy with nano-sized grains were compared with those of the comercial IN718 alloy. The oxidation resistance of the Ni20Cr20Fe5Nb1Y2O3 alloy was superior to that of the Ni20Cr20Fe5Nb and IN 718 alloys. This superior oxidation resistance was the result of both the formation of dense oxides on the surface of the alloy and the interruption of Cr migration in the alloy by the addition of Y2O3. Moreover, the tensile property of the Ni20Cr20Fe5Nb1Y2O3 alloy at room temperature and 400oC was higher than that of the Ni20Cr20Fe5Nb and IN718 alloys by more than 300MPa (30%). This result can be attributed to the dispersion strengthening of Y2O3. The relatively low tensile strength at 600°C and 800°C of the alloys fabricated by mechanical alloying was attributed to grain refinement showing intergranular fracture at high temperatures.

EFFECT OF La2O3 ON HIGH-TEMPERATURE OXIDATION RESISTANCE OF ELECTROSPARK DEPOSITED Ni-BASED COATINGS

2014 ◽  
Vol 21 (05) ◽  
pp. 1450071 ◽  
Author(s):  
YUXIN GAO ◽  
JIAN YI ◽  
ZHIGANG FANG ◽  
HU CHENG
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Kinetic ◽  
High Temperature Creep ◽  
Chromia Scale ◽  
Temperature Oxidation ◽  
Phase Structures ◽  
Short Time

The oxidation tests of electrospark deposited Ni -based coatings without and with 2.5 wt.% La 2 O 3 were conducted at 960°C in air for 100 h. The oxidation kinetic of the coatings was studied by testing the weight gain. The phase structures and morphologies of the oxidized coatings were investigated by XRD and SEM. The experimental results show that the coatings with 2.5 wt.% La 2 O 3 exhibits excellent high-temperature oxidation resistance including low oxidation rate and improved spallation resistance, due to the formation of a denser and more adherent oxide scale compared with that without La 2 O 3. The effects of La 2 O 3 on the oxidation resistance include the following two aspects: First, refinement of the coating grains promotes the selective oxidation of Cr , leading to the formation of protective chromia scale in a short time, and second, refinement of the oxide grains enhances the high-temperature creep rate, resulting in decrease of inner stress and improvement of spallation resistance of the oxide layer.

Study on Exfoliation Resistance of Ferro Superalloy Composite Oxide Scale

2012 ◽  
Vol 204-208 ◽  
pp. 4011-4014
Author(s):  
Hai Tao Wang ◽  
Shen Jie Zhou ◽  
Hua Shun Yu ◽  
Zhong Chu
Keyword(s):  
Weight Gain ◽  
Induction Furnace ◽  
Intermediate Frequency ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Composite Scale ◽  
Gain Rate ◽  
Oxidation Weight Gain ◽  
Weight Gain Rate ◽  
Complete Exfoliation

Based on ferro based superalloy K273 and heat resistant steel ZG40Cr24, test alloys were cast by intermediate frequency induction furnace with non-oxidation method by alloying of aluminium and silicon. The oxidation resistance at 1100°C for 500 hours of test alloys was carried out according to oxidation weight gain method. Experimental results show that the scale exfoliation resistance of K273 and ZG40Cr24 is reinforced greatly by Al2O3 and SiO2. The scale exfoliation weight gain rate at 1100°C descends from 1.2681g.m-2.h-1 to zero, reaching complete exfoliation resistance for ZG40Cr24 test alloy. Because of 1.5<PBR(Al2O3⁄Fe)<2 and the growing of Al2O3 and SiO2 from out side of scale-scale/oxygen interface, the composite scale grows intact and compact without accumulation of growing stress.

Effects of Boron, Silicon on Structure and Properties of Fe-Based Superalloy

2009 ◽  
Vol 79-82 ◽  
pp. 183-186 ◽  
Author(s):  
Hai Tao Wang ◽  
Hua Shun Yu ◽  
Yu Qing Wang
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Compact Structure ◽  
Temperature Oxidation ◽  
Solid Solution Strengthening ◽  
Micro Particles ◽  
High Temperature Mechanical Properties ◽  
The Matrix

The affecting laws of boron and silicon on structure and properties of Fe-based superalloy were studied by analyses of scanning electron microscope (SEM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Proper content of boron could not only purify the matrix and restrain the polymerizing and growing of carbides effectively, but also promote the forming of secondary precipitate of borides, which dispersed in form of micro particles to strengthen grain boundaries and enhance the heat strength for Fe-based superalloy. Boron was an adverse element to high temperature oxidation resistance. Silicon could toughen the matrix by solid solution strengthening. Overfed silicon in alloys caused great dropping of strength and toughness. The component of SiO2 endowed the oxide scale with flat and compact structure, fine and even grains, and few exfoliating. The optimum contents of boron and silicon in Fe-based superalloy are 0.02wt.% and 1.5wt.% respectively by comprehensive consideration of high temperature mechanical properties and oxidation resistance.

Improvement in High Temperature Oxidation Resistance of Co-Al-W Based Superalloys

2015 ◽  
Vol 1760 ◽  
Author(s):  
Takahiko Ito ◽  
Shogo Ikeda ◽  
Katsushi Tanaka
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Air Oxidation ◽  
Temperature Oxidation ◽  
Improve Oxidation Resistance

ABSTRACTOxidation tests of Cr containing Co-based superalloys with compositions of Co-20at.%Ni-9at.%Al-9at.%W-x at.%Cr (x = 2, 4, 6, 8 and 10) have been carried out at 1173 and 1273 K in air. Oxidation resistance is improved upon alloying with Cr not only at 1173 K but also at 1273 K. The weight gain of the 10at.%Cr alloy oxidized at 1173 K is similar to that of the 5th generation Ni-based superalloy of TMS-173. Alloying with Cr is efficient to improve oxidation resistance, however, the shape of γ’ precipitates is rounded and the alignment of the precipitates along the <100> direction becomes less pronounced upon alloying with Cr.

AK STEEL 441

Alloy Digest ◽  
2006 ◽  
Vol 55 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Ferritic Stainless Steel ◽  
High Temperature Oxidation ◽  
High Temperature Strength ◽  
Temperature Oxidation ◽  
Temperature Performance

Abstract AK Steel 441 has good high-temperature strength, an equiaxed microstructure, and good high-temperature oxidation resistance. The alloy is a niobium-bearing ferritic stainless steel. This datasheet provides information on composition, hardness, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SS-965. Producer or source: AK Steel.

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