Metallurgy/Questions Answered by Expert Javad Mola
| Subject | Date Asked |
| Packing fraction | 9/9/2011 |
| Q: What is the packing factor of structure BCT? A: In an extreme case where the tetragonality factor of the BCT crystal structure is zero, it can be ... | |
| 17-4 PH Y.S FAILURE | 6/8/2011 |
| Q: WHAT IS THE REASON FOR THE FAILURE OF Y.S of 17-4 Ph THOUGH OTHER MECH PROPS MEETING THE REQMT..? A: First you need to make sure that the composition is right. If yes, then it could be due to the ... | |
| Differentiating 304 grade stainless steel from 201 grade | 2/28/2011 |
| Q: I am a layman [non engineer]. I am having 700 banquet chairs manufactured in China, the frame being ... A: The magnet method will not help and I do not know any other simple and cheap method to differentiate ... | |
| strain hardening | 2/2/2011 |
| Q: sir, my straight question is Why dislocation density increases with increase of strain. A: When metals are strained, dislocations are generated and glide on certain specific crystallographic ... | |
| work hardening/slip planes | 12/18/2010 |
| Q: does pure gold have slip planes? A: Slip is a main work hardening mechanism in most metals including pure gold. Because gold has a Face ... | |
| 17-4 PH ss rehardening | 11/23/2010 |
| Q: I have a flat plate of 17-4 that has been taken to the H900 condition. Can it be annealed back so ... A: Martensitic precipitation hardenable stainless steels have an austenitic matrix in the solution ... | |
| Custom 465 Stainless | 11/22/2010 |
| Q: what effect will have on a bar(.135 Diameter x .930 long)of 17-4 Material heat treated at 900F for 4 ... A: Martensitic precipitation hardenable stainless steels have an austenitic matrix in the solution ... | |
| 17-4 heat treat | 11/15/2010 |
| Q: what effect will have on a bar(.135 Diameter x .930 long)of 17-4 Material heat treated at 900F for 4 ... A: Heat treatment of 17-4PH at 900 F (~480 degree Celsius) for 1 hr leads to the peak strength and ... | |
| STAINLESS STEEL THAT PASS NEEDLE DETECTOR | 8/31/2010 |
| Q: Does any one know a kind of stainless steel that can pass a needle detector (Machine that is used in ... A: The grades you have mentioned all have a nominally austenitic microstructure and are non-magnetic as ... | |
| Reporitng of NITROGEN in Test Certs | 6/5/2010 |
| Q: Is it mandatory to report Nitrogen content in the Test Certificates provided for Chemical ... A: The ASTM A479 standard does not indicate the nitrogen content of the 316L austenitic stainless steel ... | |
| Stretcher Strain | 6/1/2010 |
| Q: What is "Stretcher Strain" ? Is it the band son the surface of a sheet like "luders bands" ? Does it ... A: Stretcher strains are consequences of the yield point phenomenon. The yield point phenomenon is ... | |
| Stainless steel vs. Carbon steel | 5/27/2010 |
| Q: I own a manufacturing company that manufactures components for the overhead conveyor industry. Our ... A: There are certain grades of martensitic and precipitation hardenable stainless steels which can ... | |
| Temper Rolling ,Skin-pass, is to prevent? | 4/26/2010 |
| Q: "Temperrolling" or "Skin-pass" is process done to prevent wavy surface , improve surface quality , ... A: Skin pass helps prevent formation of Luders bands during the sheet forming operations of steels by ... | |
| stainless steel | 4/20/2010 |
| Q: sir I want to know that why during cold working austenitic stainless steel become magnetized? A: It is because the austenite in these steels is metastable, not stable. Therefore, application of ... | |
| physical matellurgy | 3/25/2010 |
| Q: why do the fcc crystal structure of iron absorb more carbon than bcc crystal structure of iron A: It is simply related to the fact that the size of the interstitial lattice sites are larger in the ... | |
| metallurgy | 2/23/2010 |
| Q: HOW TO CALCULATION OR DESIGN AC3 AND ACM TEMPERATURE ? A: If you are talking about the Fe-C binary system, without any other alloying elements, the answer is ... | |
| H900 HT 17-4ph | 2/3/2010 |
| Q: What would be the normal UTS range for this material and HT spec. If a component has been HT to ... A: The minimum UTS after H900 age hardening treatment of 17-4PH stainless steel is 190 ksi (1310 MPa) ... | |
| Rockwell Hardness | 1/14/2010 |
| Q: Why in this testing method we apply 2 forces? Thanks of your answer . A: First of all sorry for the late response; I failed to read the original email containing your ... | |
| iron changing from bcc to fcc | 12/1/2009 |
| Q: When iron changes from bcc structure to fcc structure, where does the extra atoms come from? Bcc ... A: The atoms do not go anywhere. What changes is only the structure. First of all, although each FCC ... | |
| differences between 201, 202,304,316&430 | 10/17/2009 |
| Q: i have similar problem that you answered in this address: ... A: I am very sorry for the delay in answering your question. I receive a lot of questions related to ... | |
| metallurgy | 10/15/2009 |
| Q: what is carbide? How can be avoided in castings? A: Carbides are compounds formed as a result of combination of carbon with other elements. In ferrous ... | |
| ss200 series/ magnetism and drawing | 10/13/2009 |
| Q: i want to draw ss200 series up dia 0.03mm(49swg) and i do not want magnetism to appear in the final ... A: The strain-induced martensitic transformation (austenite to martensite transformation as a result of ... | |
| heat treat specification | 8/27/2009 |
| Q: For 17-4SS, is it appropriate to require a specification to heat treat to Condition H900, with the ... A: Sorry I pressed the wrong button and sent you a message that I did not mean a few hours ago. I do ... | |
| stress releive 4130 fixtures | 8/6/2009 |
| Q: we are manufacturing steel tubular 4130 N engine mounts for aircraft . The new project we have is ... A: Parts of the following answer are extracted from the 4th Volume of ASM Metals Handbook entitled Heat ... | |
| Steel Strength | 6/28/2009 |
| Q: Is higher strength steel worth more than lower strength steel? A: As you probably know, increase of the strength would mean sacrifice of the ductility, so most of the ... | |
| heat treating 17-4, 15-5 stainless steel | 5/29/2009 |
| Q: I am heat treating 17-4 stainless steel. The conditions vary from 925-1150. When I do my Rockwell ... A: The times and temperatures for the precipitation hardening treatment of 17-4PH and 15-5PH vary only ... | |
| Reply to your mail | 3/19/2009 |
| Q: "Is the steel mill furnishing your AISI 316L decided?" the steel mill has sent us the ... A: The Cre/Nie I mentioned has been quoted from ASTM A800. Your reference I guess has been something ... | |
| Reply to your mail | 3/18/2009 |
| Q: "Is the steel mill furnishing your AISI 316L decided?" the steel mill has sent us the ... A: So you are not purchasing the steel from a steel mill but you are making it yourself for your ... | |
| heat treatment | 3/12/2009 |
| Q: Mr. Javad, This is actually a follow up question from yesterday! How does heat treatment relieve ... A: You are right indeed understanding the phrases "The dislocations which are internal defects created ... | |
| Metallurgy | 3/11/2009 |
| Q: Javad, Could you please explain to me what happens to metal at the molecular level when performing ... A: To answer your question it is better to first consider how residual stresses develop during ... | |
| 316 SS | 2/27/2009 |
| Q: What is the AMS spec for tempering 316/316L stainless steel? We are trying to find what the spec is ... A: Unfortunately I do not know any such specification and since it is very specialized, I believe it ... | |
| 316 SS | 2/26/2009 |
| Q: What is the AMS spec for tempering 316/316L stainless steel? We are trying to find what the spec is ... A: AISI 316 is austenitic unless quenched to sub-zero temperatures or plastically deformed. Therefore, ... | |
| Hardness testing | 2/24/2009 |
| Q: When performing hardness testing on CrMo materials, why do you get different hardness values when ... A: I guess there is a "compositional" reason behind what you are observing. In general the tentative ... | |
| Quenched and tempered | 2/12/2009 |
| Q: I have recently got a job in the oil industry suppling casing and tubulars, so I am desperately keen ... A: Carbon steels exhibit different phases at different temperatures under equilibrium conditions. The ... | |
| Yeild Strength of Stainless | 12/31/2008 |
| Q: I am looking for a food grade Stainless that would have the yield (135,000 to 148,000 psi)and ... A: For such high tensile strengths, your choice is limited to the martensitic grades of stainless steel ... | |
| Content of Stainless Steel | 12/9/2008 |
| Q: Mola, I am planning on making some small scale model trebuchets. I would like to use some metals ... A: As much as I am concerned, there is no special alloying element added to make stainless steels ... | |
| Heat Treatment | 11/14/2008 |
| Q: what difference between diagrams of IT and CT in heat treatment of steels? A: Isothermal Transformation (IT) and Continuous Transformation (CT) diagrams are diagrams used to ... | |
| alloying elements | 9/14/2008 |
| Q: 1 - What is the metallurgical explanation of effects of chromium, nickel, molybdenum and carbon in ... A: Alloying elements in stainless steels can be divided into 2 main categories namely austenite and ... | |
| Magnetism in St.St | 9/4/2008 |
| Q: I work regularly with stainless steels in the aerospace industry, mostly annealed chromium nickel BS ... A: In addition to you, this question is also of interest to many people in the stainless steel ... | |
| Cause corrosion in stainless steel | 9/2/2008 |
| Q: I'm working with particles of stainless steel and I would like to know the easiest way to attack by ... A: Promoting uniform corrosion in stainless steels is very difficult because of ready formation of a ... | |
| Heat Treated Shaft | 8/25/2008 |
| Q: I have a customer who broke a 3/4" heat treated shaft with a ball on the end that is pulled through ... A: in addition to high C content, has W and Cr in its composition. Therefore, hard tungsten and ... | |
| hardness 17-4 stainless Cond H-900 | 8/15/2008 |
| Q: I have seen conflicting data on this subject. What is the normal Rockwell hardness range for Type ... A: The typical hardness of 17-4PH in the H900 age hardened condition is 41~46HRC (with 42~45HRC as a ... | |
| Tensile strenght differences | 6/12/2008 |
| Q: One of my competitors states that his 420 SS shaft has a tensile strength of 40,000 psi. My shaft is ... A: Please first take a look at the typical chemistry of the stainless steels we are discussing: Main ... | |
| ferrite numbers | 5/30/2008 |
| Q: and Thank You in advance for any help you may be able to impart. I found this site Googling for a ... A: For sure, performing actual tests on your desirable stainless steel and under your processing ... | |
| What is SST? | 4/11/2008 |
| Q: I would like to know what sst is? I think ss is by stanless steal because I saw 316L SST but I do ... A: SST is just an alternative abbreviation for stainless steels. T might simply refer to the 2nd letter ... | |
| What is SST? | 4/10/2008 |
| Q: I would like to know what sst is? I think ss is by stanless steal because I saw 316L SST but I do ... A: You are right about the term SST; it is an abbreviation for stainless steels although other ... | |
| dislocation theory | 3/25/2008 |
| Q: how we describe strain aging on the basis of dislocation theory? A: The carbon/nitrogen atoms are important in yielding process because they interact with the ... | |
| metallurgy | 3/23/2008 |
| Q: what is proeutectoid ferrite and cementite? ANSWER: If you are not familiar with the Fe-C binary ... A: In response to your question regarding effect of alloying elements on the recrystallization ... | |
| metallurgy | 3/22/2008 |
| Q: what is proeutectoid ferrite and cementite? A: If you are not familiar with the Fe-C binary phase diagram, please try to download it before reading ... | |
| metallurgy | 3/6/2008 |
| Q: what is the metallurgy use. what is the casting and forgging, how to know casting material, ... A: Actually, you asked a question which requires a very long-winded answer. In summary, Actually, you ... | |
| heat treatment of weld | 2/11/2008 |
| Q: i m an under graduate student of metallurgical engineering. should we heat teat like quench ... A: The heat treatment procedure depends on the grade of steel you are dealing with. What I can do is to ... | |
| heat treatment of weld | 2/9/2008 |
| Q: i m an under graduate student of metallurgical engineering. should we heat teat like quench ... A: Due to rapid solidification of melt zone in arc welded carbon steels (base metal acts as a heat ... | |
| Rust on iron and steel | 1/21/2008 |
| Q: Years back it was my understanding that iron or steel will not rust if the temperature is below 70 ... A: No, it is not true. Iron has the potential to oxidize (generally termed rusting) when exposed to an ... | |
| Hydrogen fluoride | 1/16/2008 |
| Q: Please tell me any metal or alloy to protect against hydrogen fluoride?Thanks A: Please refer to pages 1166-1170 of vol. 13 of ASM handbooks for detailed information on resistance ... | |
| Normalizing A516-70 | 1/15/2008 |
| Q: Mr. Mola, I have two questions. First, what is the required temperature and duration for ... A: I could not find the normalizing temperature for A516 Grade 70 neither in the ASTM specification nor ... | |
| carbonitride | 1/9/2008 |
| Q: I'm not sure if you are knowledgable in carbonitriding or not, but I will ask this question anyway. ... A: Simply use the hardness measurement technique you used prior to carbonitriding the parts; if you ... | |
| liquid in which gold can be dissolved | 1/8/2008 |
| Q: which is the only liquid in which gold is dissolved? A: Since gold is very a noble metal, it does not dissolve in conventional solvents used to leach more ... | |
| settling of 380 alloy follow up | 12/4/2007 |
| Q: settling of the aluminum alloys 356 and 380. So if I wanted to speed up the process of settling ... A: As may be deduced from the example in my previous answer, small rotational speeds may lead to ... | |
| settling of 380 alloy follow up | 11/19/2007 |
| Q: settling of the aluminum alloys 356 and 380. So if I wanted to speed up the process of settling ... A: Indeed centrifugal forces can speed up separation of heavy atoms from light ones. So, in the ... | |
| Is there software that will allow me to build a model and be able to test the heat transfer | 10/7/2007 |
| Q: Is there a program that will let me test the conductivity of a metal like aluminum, and be able to ... A: I consulted one of my friends to answer your question because this is not my field of expertise; I ... | |
| molten metal settling | 9/27/2007 |
| Q: will aluminum alloy like 380 or 356 settle? meaning while in "Liquid form" above melting point will ... A: Sorry for the late response. And sorry if my previous answers have not been clear enough. In my ... | |
| Engine | 8/30/2007 |
| Q: e from Pakistan. I want to ask a simple question from u that what is the metallic composition of ... A: First of all, I am so sorry for the late response. Engine blocks are conventionally made of gray ... | |
| suggest me about project | 8/22/2007 |
| Q: i.t.durgapur(west bengal) india. i waana do a project related 2 material sci.can u please tell me ... A: Are you not already a B.S. student? If you are a student you need not to find any other institution ... | |
| Quenching Effect During PWHT | 8/19/2007 |
| Q: Greetings Javad- I hope you can help. I must perform a weld repair of a crack in a large AISI 4130 ... A: Please notice that this is the first time I have come across a PWHT question that I intend to ... | |
| Solution annealing | 8/10/2007 |
| Q: How is solution annealing carried out? What type of furnace is required? Does one need to heat in a ... A: Solution annealing is carried out by heating up the alloy to a temperature in which typically only ... | |
| Do u have an idea 4 me ? | 7/14/2007 |
| Q: I am a student of material science and engineering - Industrial Metallurgy in the Islamic Azad ... A: As you are a BS student, you would better choose a simple project, i.e. a project which is feasible ... | |
| molten metal settling | 7/7/2007 |
| Q: will aluminum alloy like 380 or 356 settle? meaning while in "Liquid form" above melting point will ... A: Sorry for the late response. Settling in the molten state merely depends on the density difference ... | |
| molten metal settling | 6/25/2007 |
| Q: will aluminum alloy like 380 or 356 settle? meaning while in "Liquid form" above melting point will ... A: Yes settling, due to gravity, of heavier elements takes place in the fully molten state in the ... | |
| heat treatement of steel | 5/30/2007 |
| Q: I'm an engineer working in a heat treatment unit .when we measured the hardness of steel species ... A: The difference in chemical composition and/or cross section of your parts is probably the reason for ... | |
| heat treating | 5/15/2007 |
| Q: from reading your profile this question is probably below your usual expertise. But I don't know ... A: First of all, make sure you have carefully read the instructions on your bender's catalogue and then ... | |
| Al alloy solidification | 5/3/2007 |
| Q: I have two aluminium melts of exactly the same alloy - Melt Sample A contains grain refiner, while ... A: The difference between solidification temperature of these two samples, A with grain refiner and B ... | |
| Testing stainless composition | 4/30/2007 |
| Q: Greetings. How can I find out what kind of stainless steel was used in making a stainless object? ... A: Usually, one can simply guess the general type of stainless steel i.e. tell if it is ferritic (or ... | |
| electron microscopy | 4/5/2007 |
| Q: I'm not sure what I'm asking here is in your field. I have a semiconductor specimen of AlGaAs ... A: As you had guessed electron microscopy and semiconductors are not my fields of expertise although I ... | |
| metallurgy | 4/4/2007 |
| Q: what is the grain size of lead as an element and as an alloy such as lead tin alloy A: Grain size in alloys and pure elements is a function of their solidification rate. The higher the ... | |
| composite material | 3/29/2007 |
| Q: in composite material preparation does the settling time of particles increased when the stirring ... A: In production of cast composites through mechanical stirring, where reinforcement particles are ... | |
| aluminium | 3/27/2007 |
| Q: We make aluminium moulds by press casting, can u suggest any thing so that the moulds should shine ... A: Shininess of castings depends on the surface quality of cast parts. Casting surface finish is always ... | |
| seperation anxiety... | 3/23/2007 |
| Q: I am trying to seperate Bismuth from Tin. Please tell me where I can get information about this. A: You need to find relevant books on extractive metallurgy of non-ferrous metals. There are useful ... | |
| case harden steel properties | 2/21/2007 |
| Q: Does case harden steel properties detoriates over time? especially for guns parts like bolt carrier? ... A: Exposure to high temperatures can lead to weakening of case hardening effects due to phase ... | |
| cold source | 2/16/2007 |
| Q: I am looking for a way to take a piece of copper pipe or any metal pipe and making the surface cold. ... A: You can use liquid gases for this purpose. Among liquid gases nitrogen is the cheapest one but as ... | |
| Heat transfer ratios | 2/7/2007 |
| Q: I am working on a project for school. I need to find a metal or alloy that has the best heat ... A: I have no idea about the alloy frozen food trays are made of. However, I do know that you need an ... | |
| Melting points | 2/4/2007 |
| Q: What is the melting points of E70 steel, 304,308,316 stainless steels. And what is the hotest part ... A: You may find the melting range of some frequently used stainless steels below. Steel is an alloy and ... | |
| block and crank molds | 1/2/2007 |
| Q: Wondering what material the actual molds of cast iron blocks and cranks are poured onto. My guess is ... A: A cast iron having a similar composition to the alloy being poured would be the best choice. ... | |
| 201 Stainless Steel (.8%-1.2% Ni) | 12/21/2006 |
| Q: Given current trends with nickel pricing, and thereby stainless steel surcharges, our company is ... A: I reviewed volume 1 of the Metals Handbook which is devoted to properties and selection of irons, ... | |
| Stainless Steel | 12/14/2006 |
| Q: How one can Differentiate between 304 & 316 grades of Steel (Physically)? A: As far as I am concerned, there is no physical distinction between these two grades of stainless ... | |
| Strength of Cast Irons | 11/20/2006 |
| Q: Which of different types of cast irons is stronger? Is their strength superior to steels? A: Generally, steels are considered to have better mechanical properties and also ductility. However, ... | |
| Copper Information | 11/12/2006 |
| Q: Please give me the details of Solidication pattern that will occur in Pure ETP copper A: ETP copper is practically pure. So, we should consider solidification of pure metals to describe its ... | |
| 1026 Steel | 11/11/2006 |
| Q: Can 1026 steel be welded? A: Since I am not a welding expert, I answer your question based on my general knowledge of metallurgy. ... | |
| hardening | 11/4/2006 |
| Q: what is meant by hardening ability of metals A: It is the ability of a metal to become hard (and inevitably brittle) under a given cooling rate. ... | |
| eletrical transfers | 10/23/2006 |
| Q: what metal cord transfers electricity ,and how can i tell? A: As far as I am concerned copper is known as a good and cheap conductor of electricity. Although ... | |
| Dendritic Arm Spacing | 10/12/2006 |
| Q: Good evening Sir. I currently have a requirement to measure both primary denrite and secondary ... A: I had the same problem myself for a long time till I found the 'Image Tool' software which is a ... | |
| stainless steel | 9/23/2006 |
| Q: will ss 304 with nickle percentage - 5 to 6% get rusted in water. what is nickle, chromium, carbon ... A: Chromium plays a key role in stainless steels since it forms a very thin oxide film on the surface ... | |
Javad Mola
Top Expert on this page
Expertise
I welcome questions related to the physical metallurgy of steels, preferably stainless steels.
Experience
As a PhD student of the Graduate Institute of Ferrous Technology (GIFT), I am working on a ferritic grade of stainless steel.
Organizations
Graduate Institute of Ferrous Technology affiliated to Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea. Pohang is home to POSCO, the third largest steel company in the world.
Publications
Solid State Phenomena (3), Steel Research International (1), Materials Science and Technology (1), Metallurgical and Materials Transactions A (2), Scripta Materialia (1)
Education/Credentials
BS degree in Materials Engineering earned from Isfahan University of Technology, Isfahan, Iran. MS degree in Materials Science and Engineering earned from Sharif University of Technology, Tehran, Iran. Currently PhD candidate at Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
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