Heat Treatment and Metallurgy Lab

How to calculate ASTM grian size of microstructure which have a scale bar? Grain size analysis is used as a quality control tool to ensure that alloys are manufactured to specification.  Some examples of this include verification of the heat treatment and condition of the alloy.  It can also be used to assist in understanding material failures. I have to find ASTM grain size, I would like to know is it a correct way to find the exact magnification of microstructure using scale bar . We have the microstructure test specimen of various metals at the lab. I used those microstructure test specimen to calculate the grain size using the                           Formula N*=2exp(n-1)  at magnification of 100 X measured in an area of 1 sq. inch. I want to know if it is the standard method for obtaining the average grain size. Can anyone attach the American Society for Testing and Materials document ASTM ...

Step Down ( macro-streak-flaw ) test of steel bar. Scope:- This Standard specifies a step-down test method, blue fracture test method and magnetic particle inspection method to assess the non-metallic inclusions in rolled or forged steel with the naked eye or using a magnifying glass with a magnification of not more than 10x. Test piece:- The test piece shall be machined to the dimensions given below in figure table 1 The machined surface shall not be rough but shall be fairly smooth. Test Procedure Process :- Sample preparation are complete then ,sample Deep in hydro cloric acid (HCL) temperature 70~80 Degrees centigrade for 1 Hrs. After process are complete then clean with hot & cold water . Method of Examination:- The length and the number of flaws shall be determined under good illumination cither with an unaided eye or with low magnafication 15x Terminology:- A:- For the purpose of this standard the streak flaw shall mean defects arising from n...

Compressive Strength:- Compressive strength is an effective way of measuring how much load a surface or material can bear. for this sort of strength is performed by exerting force downward on top of the objectequal and opposite force exerted upward on the bottom when L/D > 5,Buckling when L/D > 2.5, Shearing when L/D > 2.0 and friction is present at the contact surfaces,Double barrelling when L/D < 2.0 and friction is present at the contact surfaces, Barrelling when L/D < 2.0 and no friction is present at the contact surfaces, Homogenous compression. Compressive instability due to work-softening material. The compressive stress formula is:- CS = F ÷ A Compressive Strength = Load / Cross-sectional Area where  CS  is the compressive strength F is the force or load at point of failure and  A  is the initial cross-sectional surface area

Tensile test :- Introduce:- Tensile test property often are measure during development of new material and process , tensile property often are used to predict the behavior of a Material under forms of loading other than uniaxial tention. 1)-Tensile specimen and test machines. 2)- stress -strain curve , elastic versus plastic deformation. 3)-yield point , Ductility 4)-test methodology and analysis 5)-True stress and strain. Test methodology and data analysis:- 1.sample selection. 2.sample preparation.  3.Test setup. 4.Test procedure.  5.Data recording and analysis. 6.Reporting. Yield Strength Take the minimum yield in psi of the ASTM grade (see our Strength Requirements by Grade Chart for this value), multiplied by the stress area of the specific diameter (see our Thread Pitch Chart). This formula will give you the ultimate yield strength of that size and grade of bolt. Shear Strength :- First, find the ul...

Brinell hardness tester procedure:- BRINELL HARDNESS TESTING The Brinell hardness test is used for larger samples in materials with a coarse or inhomogeneous grain structure. This page describes the Brinell hardness test in detail and gives you practical information on how to apply it. Brinell Test Machine Description:- The Brinell Hardness Tester consists of a loading system, the main screw, and a dial gauge. The loading system consisting of weights, leavers and a hydraulic dashpot and a plunger arrangement is enclosed in the cast iron body of the machine. The main screw is also protected from extraneous elements by a rubber bellow. It carries the test table on its top to hold the specimen and is actuated by a hand at the base. The machine is provided with two ball indenters (of sizes 2.5mm&5mm) to transmit the test load on to the specimen DEFINITION OF THE BRINELL HARDNESS TEST:- Today, the Brinell test is performed using a Brinell hardness test unit. The machine presses a tungst...

Jominy end-quench test :- Jominy end-quench test is quite simple and easy test, and is thus, almost universally employed for the determination of hardenability. For this test, a slightly oversized bar of steel is normalisad at about 66°C (≈ 150°F) above Ac 3 , and then machined to the final dimensions of 4″ (102 mm) long and 1″ (25.4 mm) diameter. Machining removes any decarburised layer formed in the normalising treatment. The machined bar is put inside a closed box, half-filled with cast iron chips to prevent decarburisation, and then austenitised for 30 minutes at about 22-23°C above Ac 3 . Standard Jominy-test specimen and fixture :- Meanwhile, the special water-quenching device is kept ready. In this device, the diameter of the pipe opening is 1/2 inch. Specimen holder is such that the bottom of the specimen remains at 1/2 inch above the nozzle. The constant pressure of the water is such that the height of the impinged jet is 2 inch. The water temperature is 75 ± 5°F. ...

A microscope is an instrument used to see objects that are too small to be seen by the naked eye. Microstructure  is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope 🔬 The purpose here is to help identify the microstructures in steel using simple techniques based on the atomic mechanisms by which phases grow from austenite. Apart from their aesthetic beauty, microstructures become meaningful when examined in the context of their metallurgical theory. The symbols used to represent each phase are as follows: Phase Symbol Austenite γ Allotriomorphic ferrite α Idiomorphic ferrite α I Pearlite P Widmanstätten ferrite α w Upper bainite α b Lower bainite α lb Acicular ferrite α a Martensite α' Cementite θ θ Austenite:- Austenite has a cubic-close packed crystal structure, also referred to as a face-centred cubic structure  Ferrite:- Ferrite has a body-ce...