Chuck_Steak

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  1. ASTM A502 is what you will want to search. Looks like there are 8-10 grades that are all in the low to medium carbon range, some with alloying, some plain carbon. Several grades can be class 2, so that doesn't pinpoint the chemistry. Google Search turns up the standard for me.
  2. It will probably work just fine. The risk you run is the bronze is harder, grit could score the shaft instead of bury in a babbit bearing. How intricate is the shaft? If it's pretty simple, just do the bushing because it's quick, simple and potentially off the shelf. You could probably do a polymer bushing or a roller bearing and get satisfactory results. Unless you have a ton of cost and time in the components I wouldn't over think it. Just keep it oiled and I'd think you'd be fine.
  3. Black oxide, should be OK. Stainless typically not coated. Everything else: probably zinc (yellow, bright, or galvanized). Not all that typical: chrome. Usually decorative but often on hitch balls, etc. Very rare these days: cadmium. You might find Cad plating if you scrounge enough heavy equipment.
  4. Note on the sickle sections: when was still a metallurgist, I did testing for several different "OEM" manufacturers, one used 10B38, one used 1040 and one used 1045 as I recall. I also want to say they were carburizing them, but it has been a few years. Very possible others use a higher carbon material, but you might check if they are through hardened or carburized before assuming they will make cutlery.
  5. Even if you only bring to a moderately elevated temperature to prevent cast iron problems, repeated heat cycles with penetrating oil will free up a lot, just takes some time.
  6. I did alot of reading about making and casting anvils when I first started smithing. Find an anvil your budget allows for. Hammer on it until you feel you need a bigger anvil. Save your money from the get go and get the anvil you want at some point in the future. I saved my pennies for a couple years and bought a south german pattern anvil that is about 140 kg, made in the 1880s. It was my dream anvil. I'm nearly in love with it. Was worth every penny. For the same money, I may have been able to cobble together an Anvil shaped object. BUT if you do cast one, be sure to post, because that would be cool to see.
  7. The track pins I have recently worked with were produced from 4340 and induction hardened. Spark test is probably your best initial method to get an idea. Heat treat to see if it will harden. Go to your local scrap dealer who has a handheld XRF and have them test it, or spend the $100.00 to have a metallurgical lab in your area test it.
  8. From an industry perspective, most tool steels have substantial alloy additions to get a desired response to heat treatment or for the mechanical properties (wear resistance, impact toughness, high temperature strength, etc). "Tool steels" are identified by a letter and a number (M2, T15, H13, etc). The major types are described as: M: Molybdenum High-speed steels, T: Tungsten high speed steels, H: Chromium hot work steels or Tungsten hot work steels A: Air hardening, Medium Alloy, Cold work steels D: High Carbon, High chromium, cold work steels O: Oil-hardening cold work steels S: Shock Resisting steels L: Low alloy special purpose tool steels P: Low carbon mold steels W: Water hardening tool steels The other type of material is usually defined as "Alloy steel" such as the SAE/AISI 1500, 4100, 4300, 5600, 8600 series. These typically have lower alloy contents than true tool steels, but they are alloyed, typically with chromium, nickel or molybdenum singly or in combination, unlike carbon steels (SAE 1000 Steels). In commercial applications there is a huge performance and price difference between "tool steels" and "alloy steels" and they are really not interchangeable terms. I understand where the misnomer comes from, but have found it slightly confusing in a post when one refers to "tool steel" and then says the steel came from an axle or leaf spring. Probably because I deal with this jargon on a daily basis. Important for someone that is doing some advanced heat treatment and material selection, but probably not all that important for the backyard smith.
  9. The last two digits is very strongly correlated to the carbon content. That being said, as stated above, the numbers ultimately call out a grade and there are some variations in the manganese content for 10XX series steels. "The last two numbers refer to the carbon content in points with 100 points equaling 1% C. What you have to know is the allowable range for each designation." This statement is a bit of a simplification, but it is correct in that the last two (or three) numbers are referring to the nominal carbon content. There are additional requirements that are defined for the grade, but the numbers changes based upon the carbon content. So yeah, I think there is some hair splitting going on, but it is worth noting that other elements do vary beyond the carbon with changing grades in the same "family" (10xx, 11xx, etc). Per SAE J402, "SAE Numbering System for Wrought or Rolled Steel", the summarized description is: "A four-numeral series is usually used to designate standard alloy and carbon steels specified to chemical composition ranges. There are certain types of alloy steels which are designated by five numerals. The prefix E is used to designate steels which are made by the basic electric furnace process with special practices. The suffix H is used to designate standard hardenability steels. The last two digits of the four-numeral series and the last 3 digits of the five-numeral series are intended to indicate the approximate mean of the carbon range. For example, in Grade 1035, 35 represents a carbon range of 0.32 to 0.38% and in grade E52100, 100 represents a carbon range of 0.98 to 1.10%. It is necessary, however, to deviate from this system and to interpolate numbers in the case of some carbon ranges, and for variations in manganese, sulfur, or other elements with the same carbon range. The first two digits of the SAE numeral series for the various grades of alloy and carbon steel are given in table 1".
  10. A36 refers to ASTM A36, "Standard Specification for Carbon Structural Steel". This specification has rather broad chemical requirements and the focus is more on the tensile properties that result. A36 typically has a chemistry of: Carbon: 0.26 max. Manganese: Not Specified Phosphorus: 0.040 max. Sulfur: 0.050 max. Silicon: 0.40 max. The important part of the specification is the tensile strength requirements of 58 - 80 KSI, yield strength of 36 KSI minimum, and elongation of ~20%. These properties don't really matter to us, however, as once you start forging the material you have most likely substantially altered the mechanical properties. Basically you can consider A36 to be a 1018 to 1022-ish carbon steel. The "S" steel you refer to is a tool steel, there are a whole slew of tool steels with various letters (S, M, T, A, etc). This is a different naming convention for a different class of steels as compared to the SAE steel grades. There are also stainless steels which typically have a 3 digit naming system (i.e. 304), which is another variation on the numeric naming system. http://en.wikipedia.org/wiki/SAE_steel_grades That link covers alot of the common naming systems in the US.
  11. Well I did go for an even double bevel and it seems to work pretty well. I can't say I had any reason for my choice.
  12. Over the weekend I was talking to a relative of mine who was playing around making cedar shingles for a project. He was using a hatchet because he didn't have a froe on the farm. I figured this was a do-able project for my beginning forging skills. I looked around a bit and found the couple how-to's on other sites to get an idea of the various ways to construct the froe blade. I used the arc welder to finish the wrap on mine. After welding I tapered the hole slightly to hold the handle in place better. I also bent the blade prior to beveling so it straightened itself out. I used a piece of structural steel that I had from work. It was about 3/4" wide and maybe 3/8" thick. I quenched it and tempered it, although there is not a ton of carbon in the material, so it is not exceptionally hard, which I gather is just fine for this application. The handle is a piece of maple I had in the yard (didn't have anything else easily around). The black on the handle is from a torch, I was playing around. I didn't get the blade quite perfectly straight, but I was able to split some shakes pretty thin (~1/8"). All in all seems to be a success and was a fun project. Greg
  13. Hey Guys, I wanted to throw my 2C in on this discussion. By the failure circumstances, i'm going to say they failed due to Hydrogen Embrittlement (HE). Hydrogen embrittlement occurs when a susceptible material containing absorbed atomic hydrogen is subjected to a sustained static tensile stress. Steels at hardnesses greater than approximately 30 Rockwell C are susceptible to hydrogen embrittlement, with the susceptibility increasing with increasing hardness. The sustained static tensile stress is likely the result of the residual stresses from the heat treatment procedure. (Most likely it was done properly, but residual stresses are going to be present). The absorbed hydrogen is the result of the vinegar cleaning. HE cracking typically occurs within approximately 48 hours of the introduction of the hydrogen (In this case, 2 days after the start of the vinegar cleaning), so the timing is pretty much right. HE is well known in the plating industry because Grade 5 and Grade 8 fasteners are heat treated to high enough hardnesses to be susceptible. In that case the acid is from the electroplating process, however, Hydrogen can be absorbed from pickling or other acid cleaning processes. To prevent hydrogen embrittlement, a hydrogen relief baking treatment is usually specified, which is typically performed at 400F for 4 hours, within 4 hours of the introduction of the hydrogen. So if you acid cleaned the parts for a couple hours, you would then bake the part out to diffuse the hydrogen from the microstructure. If the part is in the acid for two days, then you don't really have a chance to bake the part out. If you still have the failed part, PM me, I could take a look at it on our SEM and tell you whether it was hydrogen or a quench crack or something different, assuming the fracture features weren't completely destroyed by the cleaning process after the cracks occurred. Basically I'd just open up one of the cracks and see what the fracture morphology looks like. Heck, as long as I was messing around, I'd probably polish and etch a cross section and show you what your microstructure looks like.
  14. With Flag Poles and similar, its not the one large load that you have to worry about, its the accumulation of 1000's of small loads less than the UTS, such as from wind, that will get you. A couple years ago I had to magnetic particle inspect 50+ light poles in a shopping center parking lot. Two poles had fallen over over approximately 2 years. We did a failure analysis and it was high cycle fatigue that propagated from a weld toe. The problem was that the lamps they hung off the poles was very heavy and large. The poles had more than sufficient strength to hold the lamps up, but the accumulation of wind over 3 or 4 years lead to the fatigue cracking. Every pole in the parking lot exhibited fatigue cracks, some propagating through more than 50% of the pole circumference. Probably not a factor in this situation, but something to consider when large projects are going to be suspended for long periods of time.
  15. Stainless Steel essentially breaks into 5 general categories and the following is an excerpt from some of my work training notes: Austenitic: These types have sufficient nickel and/or manganese to remain austenitic at room temperatures. These are the 2XX and 3XX series of stainless steels. They are nonmagnetic and can only be hardened by cold working. In the annealed condition, they have relatively low strength, but exhibit good toughness at all temperatures, including cryogenic. Austenitic stainless steels have generally low resistance to chloride induced stress corrosion cracking. Martensitic: These types are normally alloyed only with chromium, and possibly small amounts of nickel or molybdenum. These are part of the 4XX series of stainless steels. They are magnetic and can be hardened by conventional heat treatments, such as quenching and tempering. Depending upon the hardness (strength) level, these types are susceptible to hydrogen embrittlement. Because these steels can be heat treated, a wide variety of strength and toughness levels can be obtained. Ferritic: These types are also normally alloyed only with chromium, and possibly small amounts of nickel and molybdenum. In comparison to the martensitic grades, however, they have higher chromium contents and lower carbon contents. These are also part of the 4XX series of stainless steels. They are magnetic, but cannot be hardened by heat treatment, although they can be hardened by cold working. These types generally have higher tensile properties in the annealed condition than austenitic stainless steels, however, they do exhibit deceased toughness as the temperature decreases. These types are very immune to chloride induced stress corrosion cracking. Duplex: These types are alloyed with chromium, nickel, and normally other elements to produce a mixed microstructure of austenite and ferrite. Duplex stainless steels are normally identified only by brand names, but may have UNS numbers, especially in ASTM specifications. Duplex stainless steels combine many of the positive attributes of austenitic and ferritic stainless steels, including higher strength and stress corrosion cracking resistance of the ferritic types and improved corrosion resistance of the austenitic types. Precipitation Hardening: These types can be hardened by a low temperature (generally 900 to 1150 °F) aging process. Therefore, they can normally be machined to finish size before aging with minimal distortion or dimensional changes. The mechanical properties can be varied depending upon the aging temperature to properties similar to the martensitic grades, but with corrosion resistance similar to the austenitic grades. Therefore, they are commonly used when high strength and good corrosion resistance are required. These types are alloyed with chromium and nickel, along with elements that can be dissolved during the solution treatment and can be subsequently precipitated during the aging process, including copper, niobium, tantalum, and aluminum. These types are commonly identified by brand names, but are designated as Type 6XX in ASTM specifications. The magnetism of the stainless steels is dependent on the microstructure (as previously stated), and the microstructure is varied by heat treatment and chemistry. I thought the general grade info may be useful for reference.