Depth of Decarburization Analysis Module
Decarburization the loss of carbon from the surface of steel during heat treatment directly compromises hardness, fatigue strength, and wear resistance of finished parts. Traditional measurement by manual intercept counting or visual comparison is slow and operator-dependent, introducing variability exactly where traceability matters most. Clemex's Depth of Decarburization module automates the full ASTM E1077 procedure: it detects the complete (free-ferrite) and partial decarburization layers from the microstructure, transforms them into measuring lines, and reports total and layer-specific depths with full statistics delivering the same result every time, on every sample.
Stop measuring decarburization depth by eye. Clemex measures both layers, to the standard, in seconds.
View analysis report examples
See It In Action
Decarburization Analysis in Motion
Analysis Workflow
From Image to ASTM E1077 Result in 4 Steps
A fully automated pipeline that takes a polished, etched cross-section straight to a traceable, standard-referenced decarburization depth report.
ACQUIRE / LOAD IMAGE
Acquire/Load cross-sectional images of the heat-treated sample from your microscope or existing dataset.
DECARB LAYER DETECTION
Clemex identifies and isolates the free-ferrite and partial decarburization zones into separate classes.
DEPTH OF DECARB LAYER MEASUREMENTS
Each layer is transformed into measuring lines and a length distribution measurement is performed per ASTM E1077 across the full field.
GENERATED REPORT
Statistics, depth distribution histograms, and overlaid images are compiled into a ready-to-share ASTM E1077 report.
Analysis Mode
Semi-Automatic
The operator selects the decarburized zones, adjusts binary joins, removes imperfections, and verifies the bitplanes before depth statistics are finalized.
Fully Automated
Detection, segmentation, and depth statistics run automatically across a batch of fields or samples, cumulating results into a single consolidated report.
Threshold-Based
Classic gray-level thresholding isolates the complete and partial decarburization layers, giving experienced metallographers fine-grained control over detection.
AI-Powered
A trained AI model detects both decarburization layers automatically, adapting to contrast and etch variation without manual threshold tuning.
Measurement Output
Key Decarburization Depth Metrics
For every field analyzed, Clemex computes the full set of depth and statistical descriptors required by ASTM E1077, giving labs a complete, traceable picture of decarburization severity for both layers simultaneously.
Total Decarburization Depth (µm)
Full depth from surface to unaffected core, combining both the free-ferrite and partial transition layers. Primary acceptance criterion per ASTM E1077.
Partial (Top) Free-Ferrite Depth (µm)
Depth of the outermost complete decarburization zone, where carbon is entirely absent and the microstructure shows pure ferrite. Highest-impact layer for fatigue life.
Partial 2 Transition Zone Depth (µm)
Depth of the carbon-gradient zone below the free-ferrite layer, where carbon progressively increases back toward the core nominal content.
Statistical Descriptors (per Layer)
Mean Depth (µm)
Average depth of each decarburization layer across all measured positions in the field the single most reported quantity for specification compliance.
Min / Max Depth (µm)
Minimum and maximum depth values across the field, capturing the true range of decarburization severity rather than just the average.
Standard Deviation & 95% Confidence Interval
Spread and confidence of the measurement essential for statistical process control and supplier qualification packages.
Count, % RA & Range
Total number of depth measurements, relative accuracy (%), and the full depth range, providing a complete picture of measurement confidence across the field.
Key Features
Everything You Need in One Module
From image acquisition to final depth report, Clemex covers the complete ASTM E1077 decarburization measurement workflow.
AI-Powered Layer Detection
- Automatic detection of both free-ferrite and partial decarburization layers into separate bitplanes
- Artifact elimination tools remove scratches, pits, and preparation noise before any depth measurement
Full ASTM E1077 Compliance
Total, complete, and partial decarburization depths, with mean, min, max, standard deviation, 95% confidence interval, % relative accuracy, and range all computed exactly as defined by the standard, with traceable methodology on every report.
Dual-Layer Simultaneous Measurement
Both the free-ferrite zone and the partial carbon-gradient layer are measured simultaneously in a single analysis pass. No need to run separate routines for each layer Clemex reports all depths on one screen and one report.
Speed & Batch Processing
Analyze large batches of fields or specimens automatically, cumulating depth statistics and distribution histograms across the entire run ideal for high-throughput incoming inspection of spring wire, tool steel bar, and heat-treated fasteners.
Hardware Flexibility
Compatible with any microscope, camera, or motorized stage from any manufacturer at any calibrated magnification, from 50× overview scans to 500× fine-feature resolution. Microscopy Systems & Imaging Hardware
Customizable Analysis & Reporting
Tailor gray thresholds, binary join rules, artifact filters, measurement calibration, and report templates to your specific steel grade, etchant, and quality specification once configured, apply consistently across a full batch.
Where Decarburization Matters
Materials & Industries Where Depth Measurement Is Critical
Decarburization depth is a rejectable defect across a wide range of heat-treated steel products. Clemex adapts to the etch contrast and microstructure of each material without switching models or reconfiguring settings.
Why It Matters
Even a thin decarburized layer at the surface can reduce fatigue limit by 20–30% in spring steel, trigger premature spalling in bearing raceways, or cause thread stripping in heat-treated fasteners. ASTM E1077 sets the standardized framework for quantifying this risk with a reproducible, automated measurement.
Frequently Asked Questions
What is decarburization and why does it need to be measured?
Decarburization is the loss of carbon from the surface layer of steel during high-temperature processing annealing, forging, rolling, or heat treatment in atmospheres with insufficient carbon potential. As carbon diffuses out of the surface, the microstructure transforms into low-carbon ferrite or a carbon-gradient transition zone, which is significantly softer and more ductile than the base material. This surface softness reduces hardness, fatigue limit, and wear resistance. In spring steel, a free-ferrite layer even a few tens of microns deep can reduce fatigue life by a factor of two or more. ASTM E1077 defines two distinct layers to quantify complete (free-ferrite) and partial and requires that both be measured and reported separately.
A thin soft layer with large consequences for fatigue and wear life
What is the difference between complete and partial decarburization?
Complete decarburization is the outermost zone where all the carbon has been lost, leaving a microstructure of pure ferrite with no pearlite or other carbon-bearing constituents. This layer appears bright and featureless after etching. Partial decarburization is the transition zone below it, where carbon increases progressively from zero at the surface back to the nominal core content. This zone shows a visible color gradient under etch the darker the region, the more carbon-bearing constituents have been preserved. ASTM E1077 requires both to be measured separately, and Clemex assigns each to a distinct bitplane so both depths are computed simultaneously.
Two distinct layers, two different risks, one automated measurement
How does Clemex detect and separate the two decarburization layers?
Clemex binarizes the cross-sectional image using gray-level thresholding or AI-powered detection. The free-ferrite zone, which appears distinctly bright on nital-etched carbon steel, is captured in one bitplane (rendered in blue in the overlay). The partial decarburization zone, which shows a color gradient between the free-ferrite and the unaffected core, is isolated into a second bitplane (rendered in red). Binary join and connect operations bridge small gaps caused by surface roughness or incomplete etching, and artifact elimination tools remove scratches and preparation debris before any measurement is taken. Each bitplane is then transformed into vertical measuring lines and subjected to length distribution analysis.
Two separate bitplanes, independently cleaned and measured
What statistics does the Clemex report include per layer?
For each layer total, partial (top/free-ferrite), and partial 2 (transition zone) Clemex reports: mean depth (µm), minimum and maximum depth, standard deviation, count (number of measured positions), 95% confidence interval, relative accuracy (% RA), and the full depth range. A depth distribution histogram is generated automatically for each layer, and all raw data points are linked to their source objects in the image for individual traceability and validation. The final report is print-ready directly from Clemex Vision.
Full statistics, histogram, and linked raw data on every run
Can Clemex handle cases where only partial decarburization is present (no free-ferrite layer)?
Yes. ASTM E1077 accommodates samples where no complete (free-ferrite) decarburization zone is visible for example, in lightly decarburized wire rod where only a carbon-gradient transition zone is present. In such cases the free-ferrite bitplane remains empty and its depth is reported as zero, while the partial transition zone is measured normally. Conversely, if both layers are present, both are measured simultaneously. The module adapts to the actual microstructure rather than requiring a specific layer configuration to be present.
One layer or two the module adapts to what's actually present
Is the analysis output traceable and suitable for quality certification?
Yes. Every Clemex decarburization report includes the analysis date and time, operator identification, sample ID, magnification, calibration, etchant, and a complete reference to ASTM E1077. Raw data points are linked to their respective measurement objects in the image, so any individual depth reading can be traced back to the exact location on the cross-section. This makes the output suitable for incoming inspection acceptance records, supplier qualification audits, and customer-facing quality certificates in automotive, aerospace, and fastener applications.
Full traceability from pixel to report, built into every run
Can batch decarburization analysis be run across many samples automatically?
Yes. Clemex supports fully automated batch processing across any number of fields or specimens. Depth statistics for all three layers are cumulated automatically across the batch, and a consolidated report with histograms and summary statistics is generated at the end of the run. This is particularly valuable for wire rod and bar incoming inspection, where every coil or heat must be measured and documented before release to production.
One sample or an entire coil lot same automated workflow
Ready to Standardize Your Decarburization Measurement?
Talk to a Clemex expert and get a live demo on your own heat-treated steel samples. No commitment required.
