Search results
Oct 18, 2018 · ASTM A439 Type D-2B is the ASTM designation for this material. F43001 is the UNS number. Additionally, the British Standard (BS) designation is S2B. And the AFNOR (French) designation is FGS Ni20 Cr3. The graph bars on the material properties cards below compare ASTM A439 type D-2B to: cast irons (top), all iron alloys (middle), and the entire ...
May 25, 2020 · ASTM A439 Austenitic Ductile Iron Chemical Requirements: Generally, the austenitic ductile iron castings may be stress relieved by heating to 1150 to 1200°F (621 to 650°C) for not less than 1 h nor more than 2 h per inch of thickness in the thickest section. Heating and cooling shall be uniform and shall not be more than 400°F (222°C)/h for ...
People also ask
What is ASTM A439 type D2B?
What is the difference between Ni-resist D2 & D-2B?
What is Ni-resist D2 ductile grade?
Why is alloy D2W a good welding material?
- General Characteristics of the Ni-Resist Austenitic Cast Iron Alloys
- Part I The Alloys
- EFFECT OF COMPOSITION ON STRUCTURE AND PROPERTIES
- Chromium
- Copper
- Carbon
- Silicon
- Magnesium
- MECHANICAL PROPERTIES
- Elongation (Ductility)
- Modulus of Elasticity
- PHYSICAL PROPERTIES
- Electrical Resistivity
- Machining
- Normalizing
- WELDING
- Corrosion Resistance
- Thermal Expansion
- Electrical Resistivity
- FIELDS OF APPLICATION
- Chemical Processing
- Petroleum Industry
There are two families of Ni-Resist austenitic cast irons. These are the standard or flake graphite alloys and the ductile or spheroidal graphite alloys. As time passes, the spheroidal grades, because of higher strength, ductility and elevated temperature properties, are becoming more prominent. However, the flake materials with lower cost, fewer f...
The Ni-Resist cast irons are a family of alloys with sufficient nickel to produce an austenitic structure which has unique and superior properties. The family is divided into two groups. These are the standard or flake graphite alloys and the ductile or spheroidal graphite alloys. Except for the copper containing ones, the groups have materials sim...
Each of the alloying elements in the iron base of the Ni-Resists affects the structure and/or properties in different ways. The intentional additions make important and necessary contributions. The following is a brief synop-sis of the unique effects of these substances.
The most important effects of chromium are improve-ments in strength and corrosion resistance at ele- vated temperatures. It also causes increased hardness which improves wear and corrosion/ero- sion resistance. Chromium decreases ductility by forming a higher percentage of hard carbides. Higher chromium can lead to a greater propensity for micro-p...
Copper improves corrosion resistance in mildly acidic solutions. It interferes with the magnesium treatment used to produce spheroidal graphite and cannot be added to ductile Ni-Resists.
Carbon is a characteristic element in all cast irons. High carbon reduces the solidification temperature and im-proves the melting and pouring behaviour. Lower carbon contents usually lead to fewer carbides and higher strength and toughness.
Silicon is another essential element in cast irons. It improves fluidity of the melt which leads to better casting properties, especially for thin-walled sections. Silicon also contributes to greater high temperature corrosion resistance. This element lessens chromium carbide formation.
A necessary ladle addition which leads to the formation of spheroidal graphite in the ductile Ni-Resists. Only a very small quantity is present in castings.
Tables V and VI list the nominal mechanical properties for flake and spheroidal graphite Ni-Resist alloys, re-spectively. These are average values given for guidance only. Mechanical properties can be varied by heat treatment and by altering the levels of carbon, silicon, chromium and, if desired, molybdenum. For unique service requirements, specia...
As seen in Tables V and Vl, elongation values for the spheroidal graphite varieties are significantly higher than for the flake graphite alloys. This is also true when comparing the spheroidal types to normal and alloyed gray cast irons. Higher chromium content will lower ductility in the spheroidal graphite alloys because of an increased amount of...
The moduli of elasticity of the flake graphite alloys are similar to those for gray cast iron. For alloys of similar chemical composition, the values are slightly, but not significantly, higher for ductile Ni-Resists. Typical values are given in some of the mechanical property tables in the specifications in Part II.
Tables VII and Vlll list the average physical properties for flake and spheroidal graphite alloys. These also are average values given for guidance only. Refer to Part II for physical properties required or expected in some of the national and international specifications.
The electrical resistivity of some of the alloys is given in Tables Vll and Vlll. In general, the spheroidal graphite alloys have lower values. If electrical conductivity is an important property, they are usually preferred.
The machinability of Ni-Resist alloys is inferior to that of pearlitic gray cast iron but usually better than cast steels. The chromium content is the most important factor in determining the machinability of the various grades of Ni-Resist alloys. As chromium content increases machin-ability is reduced because of increasing amounts of hard carbide...
The same heat treatment that is used for high-tempera-ture stabilization can be used for normalizing. It will result in an increase in yield strength and elongation.
Ni-Resist alloys are all capable of being welded, provided that correct welding parameters are followed and that sulfur and phosphorous contents are controlled to proper limits. The degree of welding that is possible varies from alloy to alloy as described in the following. In general, the flake graphite Ni-Resists are slightly tougher and more duc...
It is usually said that Ni-Resist alloys have a corrosion resistance intermediate between gray and low alloy cast irons and stainless steel. This statement is an over- simplification of their usual form of corrosion. They cor- rode in a manner similar to the gray cast irons, but because of their chemical composition, form denser, more adher- ent co...
The Ni-Resist alloys have a wide range of coefficients of thermal expansion. These differences have been exploited in a number of ways. Average values for the various alloys are given in Tables Vll and Vlll. Reference should be made to Part II for the national and international specifications.
As can be seen from Tables VIl and Vlll and the specifica-tions in Part II, the electrical resistivities of the flake graphite alloys are higher than for the corresponding ductile ones. Table XXI shows they are also higher than the values for gray cast iron and carbon and stainless steels. This properly is advantageous in certain electrical applica...
Throughout the text, numerous examples of applications of Ni-Resist alloys have been mentioned. In this section, we have grouped them by industry area and have in-cluded some additional uses. There are also a number of pictures of finished and unfinished castings intended for various applications.
Chemical equipment requires the ability to withstand long periods of service under a wide variety of corrosive conditions. For those applications in chemical plants where cast components are suitable and economical, the Ni-Resist alloys are widely and successfully used. Some of the more frequent applications are: Blowers Compressors Condenser par...
60 When petroleum fluids enter feed lines, refineries and other processing plants, they must be distributed to the processing equipment. In addition, large quantities of water are often required in the various operations. In all of this, corrosion resistant materials are needed. For cast parts, Ni-Resist alloys have proved to be very successful. Th...
- 931KB
- 40
Among all the ASTM A439 Type D-2B ASTM A439 elements. Carbon is hardening element. Silicon helps to strengthen the strength. Manganese is the important austenite stabilizing elements contribute to the formation of texture structure and increase the firmness, strength and wear resistance. Phosphorus reduces the plasticity and toughness and ...
Oct 18, 2018 · ASTM A439 Type D-2 is the ASTM designation for this material. F43000 is the UNS number. Additionally, the British Standard (BS) designation is S2. And the AFNOR (French) designation is FGS Ni20 Cr2. The graph bars on the material properties cards below compare ASTM A439 type D-2 to: cast irons (top), all iron alloys (middle), and the entire ...
Melting point is the temperature at which a solid-liquid phase change occurs. 1316 - 1595 °C. Show Material materials with Melting point of 1316 - 1595 °C. Typical for Nickel Steel. Specific heat capacity. Heat capacity measures the amount of energy needed to change the temperature by a fixed amount, per unit volume.
Fig. D - Ni-Resist ductile iron Type D-2B (3 % Chromium) Microstructures of test bars cast of NI-RESIST irons. lOOX magnification, 2% nital etch. Types 2 and 2b : as cast Types D-2 and D-2B: heat treated, 5 hours at 1800 F, air cooled Note: The increase in carbides between the types containing 2% chromium (left)
