ASTM E112 outlines the test procedure for the average grain size of metals and alloys. The standard applies the comparison, planimetric, and intercept methods for measuring grain size in suitably prepared and etched specimens. It includes three methods for assessing grain size from metallographic specimens: comparison, planimetric, and intercept. Representative specimens are prepared, polished, and etched and then examined under proper magnification for the grain structure. The average grain size of metals is then calculated by applying the appropriate ASTM E112 (Standard Test Methods for Determining Average Grain Size) procedure and reported as a grain-size number or as the measured grain size.
ASTM E112 Determining Average Grain Size
What is ASTM E112?
What is the Scope of the ASTM E112 Test Standard?
ASTM E112 describes metal microstructure characteristics, aids materials quality control, compares processing conditions, and determines grain-size requirements for metal products. This standard includes several methods for measuring the average grain size of metals and alloys. The standard offers three approaches to grain structure evaluation – comparison, planimetric, and intercept. The ASTM E112 standard-
- Determines the average grain size of metallic materials.
- Gives comparison, planimetric, and intercept procedures.
- Determines the structure of grains in prepared metallographic samples.
- Supports grain-size determination for single-phase and some multiphase materials.
- Standardizes grain-size numbers for reporting purposes.
- Assists in the assessment of uniformity in grain size and microstructure of the material.
- Carries out quality control and material characterization.
What are the Uses of ASTM E112 Testing?
ASTM E112 testing helps laboratories determine the grain structure of metallic materials. The results are used by engineers in assessing the processing conditions, comparing the microstructures of the materials, and in quality-control programs. This standard-
- Calculates the average grain size.
- Evaluates metallic microstructures.
- Supports heat-treatment evaluation.
- Assists in comparing the various material conditions.
- Helps maintain the quality of manufacturing.
- Assists in ensuring that grain-size requirements are met.
- Delivers uniformity in grain-size measurements for material evaluation.
Which materials can be tested under ASTM E112?
ASTM E112 applies primarily to metallic materials and alloys whose grain structures can be properly revealed through metallographic preparation. The procedure depends on the structure, grain morphology, and condition of the specimen. The grain size evaluation should be carried out on representative specimens, and suitably polished and etched surfaces should be prepared in the laboratory prior to the grain size evaluation.
Why is ASTM E112 Important?
The grain size of metals and alloys is determined by ASTM E112, which sets out standard procedures for the determination of average grain size in metals and alloys. Uniform grain size measurement can assist manufacturers in assessing microstructural features that may affect the performance of their material. The results can also be used for comparison of the properties of a metallic material, for considering manufacturing or heat-treatment conditions, and for judging whether the material conforms to applicable requirements for grain size.
ASTM E112 Equipment and Sample Preparation Guide
ASTM E112 requires the correct preparation of metallographic specimens and the proper equipment for observing and measuring the grain structure. The choice of the grain-size method depends on the grain size of the specimen and the type of microstructure.
| Sample and Specimen Details | Representative metal specimens are prepared in laboratories so the surface is polished to clearly show the grain structure after metallographic preparation and etching. |
| Specimen Preparation | Technicians section, grind, polish, and etch the specimen to clearly expose the grain boundaries if needed. |
| Specimen Dimensions | Specimen size varies with the material and sampling site, and the prepared surface should provide a representative area for grain-size determination. |
| Instrumentation | The evaluation is done with the help of a metallurgical microscope, a calibrated measurement system, appropriate illumination, equipment for specimen preparation, and a grain size comparison or measurement system. |
Testing Procedures and Requirements for ASTM E112
There are three major methods for estimating grain size as described in ASTM E112: the comparison procedure, the planimetric procedure, and the intercept procedure. The technician chooses the correct method based on the material and grain structure. The ASTM E112 test procedure is as follows-
| Comparison Method | Analysts compare the specimen structure with the standard grain-size charts at the appropriate magnification and record the closest matching grain-size number. |
| Planimetric Method | Analysts select a representative area of the specimen, count the grains within the test area, and calculate the average grain size from the measured grain count. |
| Intercept Method | Analysts apply test lines or grids across the grain structure, count the number of grain-boundary intersections, and calculate the average intercept length. |
| Grain-Size Evaluation | Analysts analyze representative sections at the appropriate magnification and use the measured values to determine the average grain size. |
| Result Reporting | Laboratories report the applicable ASTM E112 method, the grain-size number or calculated grain dimension, the magnification, information about the specimen, and observations relevant to the ASTM E112 method. |
ASTM E112 Testing Process and Data Collection
Representative material samples are selected by the analysts, and metallographic sections are prepared in accordance with the material and the desired assessment. Next, the specimen is polished and etched to expose the grain boundaries. Analysts then analyze the prepared microstructure by the appropriate comparison, planimetric, or intercept procedure. Technicians take either grain counts or intercept measurements or comparison observations, depending on the method chosen. Finally, laboratories either calculate or assign the average grain size and enter the ASTM grain-size number or measured grain dimension.
Common Challenges and Troubleshooting
Representative sampling, proper metallographic preparation, clear grain-boundary revelation, and the proper method selection are all important factors in obtaining accurate ASTM E112 results. Grain boundaries can be hard to see when the polishing or etching is poor, and this can influence the measurement. Areas of preparation artifacts should be avoided, and representative fields should be examined by the technician. Grain-size evaluation also is enhanced by proper magnification and consistent measurement procedures.
ASTM E112 Analysis Results and Interpretation
The report summarizes the mean grain size obtained from the prepared metal specimen using the selected procedure. Laboratories may report the ASTM grain-size number and the dimensions of the grains measured.
- ASTM E112 is used to obtain average grain-size results, not a single mechanical property.
- The ASTM grain-size number can be used to report grain size.
- When possible, the laboratory can report the average grain diameter or mean intercept length.
- Results should indicate the test method and condition of the specimens used.
- Using consistent specimen preparation and representative measurements allows laboratories to obtain reliable results.
Get Certified ASTM E112 Testing for Reliable Grain Size Analysis
The grain size may affect some of the important mechanical and physical properties of metallic materials. Hence, manufacturers employ standard grain-size measurement to assess material consistency and to know the effects of processing and heat treatment. There are standard procedures for calculating average grain size. These results can be used by engineers to assess the microstructure, compare materials, aid quality control, and check grain-size specifications for metallic products.
FAQ
Where can I get the astm e112 tested?
You can share your astm e112 testing requirements with MaTestLab. MaTestLab has a vast network of material testing laboratories, spread across the USA and Canada. We support your all material testing needs ranging from specific astm e112 test to various testing techniques.
How much do I need to pay for the astm e112 test?
Please contact us for a detailed quote for your astm e112 testing needs. Cost incurred to carry out different astm e112 testing methodology depends on the type of raw material; number of samples, coupons, or specimens; test conditions, turn around time etc. Costs of some ASTM testing methods start from $100 and the final value depends upon the factors listed above. Please contact us for the best and latest prices.
How many samples are required for astm e112?
The required number of samples or specimens should comply with the procedure given in the astm e112 standard. However, the MaTestLab operations team can assist you for your special requirements once you share your testing details with us.
How much discount can I get on the astm e112 test?
MaTestLab has a vast testing laboratory network, hence we bring you the best testing facilities in a cost-effective way. We offer considerable discounts (15-20%) to our returning customers based on test volume and frequency.
How many days will it take to complete the astm e112 test?
The turnaround time for astm e112 test methodology depends upon the test procedure mentioned in the standard test document. However, we at MaTestLab understand your research requirements and hence try to get your test completed within the least possible time.
Testimonials
Real results
Engineers trust us with what matters most
“We had a great experience working with this company for our ASTM E84 testing. They were the first company to respond to our inquiry within just a few minutes of submitting it. From start to finish, the communication was excellent, and the entire process was swift, straightforward, and hassle-free.”
“Very good communication, testing associates were very patient with delays on our end. Reasonable turnaround time for results and nicely detailed report. Analysts were also quick to answer any follow-up questions. Happy with results.”
“Matestlab connected us with an accredited lab within days, cutting weeks off our product validation timeline.”
Start Your Testing
Project Today
Project Today
Define your requirements and get access to
specialized laboratories ready to deliver results
specialized laboratories ready to deliver results
Start Testing
Partners with us
Clients
Vendors