Metallurgical Associates

Metallography March Alloy Steel A combination or mixture of various elements with iron and less than two percent carbon is referred to as an alloy steel. The characteristics and performance of alloy steels are determined by which elements are combined with the iron, and in what quantities. Typical alloying elements that may be used include manganese, chromium, nickel, molybdenum, vanadium, and silicon but this list is by no means complete. Different alloy steels are identified by a number or number/letter designation. These designations are set by various organizations such as the American Society of Testing and Materials (ASTM) and the Society of Automotive Engineers (SAE).?Many European countries and Japan also have their own alloy steel designation systems.?Since there are several hundred types of alloy steels and numerous organizations issuing their own designations for them, the subject of identification can become somewhat involved. An international unified system has been discussed on and off for many years but has not been seriously pursued to date. Alloy steels are usually intended to be heat treated and can be hardened to a greater depth than carbon steels of comparable carbon content. Alloy steels may also be tougher than carbon steels of comparable carbon content. Alloying elements are expensive, and the production of alloy steels can be more complex than that of carbon steels. As a result, alloy steels are generally more expensive than carbon steels. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis

Metallography March Metal Eating Bugs? Microbiologically Induced Corrosion (MIC) A type of corrosive attack which is caused by a type of bacteria which, as a by-product, produce a highly corrosive localized environment. Microbiologically induced corrosion can progress rapidly once it is initiated, and it is not unusual for cast iron water pipes, for example, to perforate by MIC in a very short period of time. Many of the organisms which are responsible for MIC are not harmful to humans and can be present in drinking water with no health impact on the consumer. Microbiologically induced corrosion can be identified and differentiated from other types of corrosive attack by optical and scanning electron microscopy and by chemical analysis of the adhered corrosion product. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis

Metallography Madness Gas Porosity Voids or holes in a weld or casting caused by the presence of entrapped or dissolved gases in the molten metal which cannot escape as the metal cools and solidifies. Gas porosities are normally spherical in shape, although they can take on other forms such as "worm hole" shaped voids. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis

Metallography March Grains The vast majority of metals are composed of tightly interlocked crystals or grains. These grains are analogous to cells in plant or animal tissue. In most cases these grains are very small and can only be resolved by microscopic examination. Individual grains are composed of a three dimensional grouping of atoms called a cell or lattice. The size and orientation of the grains in a material can have a significant affect on its properties and characteristics and can be altered, either intentionally or unintentionally, by manufacturing processes and service environment. Check out our photos of different grain sizes in copper! Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis

Metallography March Pitting Pitting is an extremely localized form of corrosive attack which results in a distinct "crater" with a well defined rim. All industrial metals and alloys are susceptible to pitting under certain environmental conditions.?Pitting corrosion is initiated when a corrosive material is deposited at localized surface features on a metal part such as crevices or when a localized area of a metal surface becomes anodic (positively charged) relative to the rest of the surface. This anodic reaction is a common cause of pitting corrosion on stainless steels. Stainless steels have a surface film of chromium oxide which protects them from corrosive attack, giving them their generic name--stainless steel. When this chromium oxide film is breached at a localized area, the unprotected sub-surface becomes anodic, relative to the surrounding, still-protected surface.?Such a condition, in combination with a corrosive environment, will result in the initiation of pitting corrosion. Pitting corrosion can be very difficult to detect by visual examination because the localized nature of this type of attack generates small, often isolated pits. Pitting can result in rapid perforation through the wall thickness of components such as pipe and tubing, leading to leakage in systems subjected to this attack. Due to the speed with which this attack can progress, it is usually not practical to compensate for the possibility of pitting by increasing the material's thickness. Changes in a component's composition and/or environment or employment of a corrosion resistant coating are normally required to prevent future pitting corrosion. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis

Metallography Madness Precipitation Hardening Stainless Steel A stainless steel containing copper, aluminum, and/or niobium. These elements are finely dispersed throughout this material when it is heated to temperatures ranging from 900 to 1150°F and then held at these temperatures for an extended period of time. This process is known as aging and gives precipitation hardening stainless steels corrosion resistance properties similar to austenitic stainless steels and a degree of strength similar to martensitic stainless steels. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis??

Did you know that MAI doesn't just have clients who want failure analyses? We help clients with material selection to ensure they have the right material for their intended purpose in certain environments. We also help clients with routine product testing. Need some metallurgical testing or information, please reach out to MAI today 262-798-8098 or [email protected] #mai #metallurgy #SEM #welding #scanningelectronmicroscopy #EDS #failureanalysis #routineproducttesting If you want to stay up-to-date with us, follow our Page.

Metallography Madness Ferritic Stainless Steel Ferritic stainless steels contain a relatively high percentage of chromium (~10-30%), but unlike most other grades of stainless steel, ferritic types contain little or no nickel. Other alloying elements include silicon and manganese, as well as several others specific to particular variations. Ferritic stainless steels, along with martensitic stainless steels, are identified with a 400 series number which refers to each specific alloy variation such as types 405, 409, 430, etc.?Although they cannot be hardened by heat treating, ferritic stainless steels can be work hardened (i.e., hardened by plastic deformation). Unlike Austenitic stainless steels, Ferritic stainless steels are magnetic.? Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis??

Metallography Madness Martensitic Stainless Steel A family of stainless steels whose major elemental components are chromium and iron, but unlike many other types of stainless steel, they contain little or no nickel. Also unlike many other types, martensitic stainless steels contain up to 1 percent carbon and, therefore, can be hardened by heat treating. Because of this characteristic, along with their resistance to staining and corrosion,?martensitic stainless steels are used in fine cutlery which demand a hard, sharp cutting edge, along with many other applications requiring these qualities. Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis??

Metallography Madness Austenitic Stainless Steel A stainless steel containing a relatively large percentage of manganese, chromium, nickel, and nitrogen, as well as other elements in some types. Molybdenum is another common alloying element in some austenitic stainless steels. When present in these relatively large percentages, these alloying elements remain in solution (dissolved) with the iron at ambient temperature rather than precipitating out of solution into small distinct concentrations, as might occur with smaller amounts of these alloying elements present. This property of retaining large amounts of alloying elements in solution at ambient temperature is common to all austenitic stainless steel types. Austenitic stainless steels are usually designated as 300 series stainless steels, and some of the more commonly used types include 301, 302, 304, and 316. They are non-magnetic and normally soft and ductile, even at very cold (cryogenic) temperatures. Although they cannot be hardened by heat treating, austenitic stainless steels can be work hardened (hardened by plastic deformation).?? ? Contact MAI today for all your testing needs 1-262-798-8098 or [email protected]? ? #metals #metallurgical #metallurgicalengineering #sem #welding #qualityassurance #engineering #eds #scanningelectronmicroscope #weldanalysis??