Steel Rolling Member Hydrogen Severity via Non-Diffusible Hydrogen

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Solution Overview

Problem

Accurately assessing hydrogen environment severity and predicting white structure damage in rolling devices is challenging due to the difficulty in measuring room temperature diffusible hydrogen, which is rapidly discharged, and the complexity of quantifying hydrogen gas concentration and lubricant decomposition in actual machine operations.

Innovation Solution

A method that measures the increase rate of room temperature non-diffusible hydrogen in rolling fatigue regions and uses this data to assess hydrogen environment severity and predict white structure damage likelihood, by correlating the increase rate with operating conditions such as stress, temperature, and hydrogen environment factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If room temperature diffusible hydrogen is measured to assess hydrogen environment severity, then accurate assessment of hydrogen environment severity and prediction of white structure damage can be achieved, but the measurement becomes difficult because diffusible hydrogen is discharged from the rolling member before measurement

Engineering Contradiction:
Improvehydrogen environment severity assessment accuracyVSAvoidroom temperature diffusible hydrogen measurement difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The invention changes the measurement parameter from room temperature diffusible hydrogen to room temperature non-diffusible hydrogen. By measuring non-diffusible hydrogen instead of diffusible hydrogen, the measurement becomes feasible while still enabling assessment of hydrogen environment severity and prediction of white structure damage through established correlations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses room temperature non-diffusible hydrogen as an intermediary substance to indirectly assess the hydrogen environment severity. Since non-diffusible hydrogen can be measured accurately and correlates with diffusible hydrogen levels, it serves as a reliable proxy for the original measurement goal.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If hydrogen environment severity is assessed using diffusible hydrogen measurement, then white structure damage prediction is possible, but the measurement process becomes impractical in actual machine operations due to hydrogen discharge

Engineering Contradiction:
Improvewhite structure damage prediction reliabilityVSAvoidmeasurement operation feasibility in actual machines
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention changes the measurable parameter from diffusible hydrogen to non-diffusible hydrogen, making the assessment operationally feasible in actual machine conditions while preserving the reliability of white structure damage prediction through validated correlation models.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The rolling member itself provides the measurement data through its non-diffusible hydrogen content, eliminating the need for complex external measurement systems or interventions. The material's own hydrogen retention properties enable the assessment.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If direct measurement of hydrogen gas concentration and lubricant decomposition is performed, then accurate hydrogen environment evaluation is possible, but the measurement complexity and difficulty increase significantly

Engineering Contradiction:
Improvehydrogen gas concentration measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention uses non-diffusible hydrogen content in the rolling member as an intermediary that integrates information about hydrogen gas concentration and lubricant decomposition without requiring direct measurement of these separate parameters. This simplifies the measurement system while maintaining assessment accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention merges multiple measurement objectives (hydrogen gas concentration, lubricant decomposition, hydrogen environment severity) into a single measurement of non-diffusible hydrogen content, reducing device complexity while achieving comprehensive evaluation.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3889569B1Ambient-hydrogen-level assessment method and white-structure-damage-likelihood prediction method
Publication Date: 2023.05.03 NSK LTD
  • EP3889569B1 patent drawingFigure 1~2
  • EP3889569B1 patent drawingFigure 3
  • EP3889569B1 patent drawing

AI summary

Provided are a method for assessing hydrogen environment severity of a rolling device during operation and a method for predicting likelihood that white structure damage occurs to the rolling device as a result of operation. A hydrogen environment severity assessment method is a method for assessing, among operating conditions of a rolling device including two rolling members coming into rolling contact with each other and having at least one of the two rolling members being a steel rolling member, hydrogen environment severity, the hydrogen environment severity being an index representing magnitude of influence exerted by hydrogen. The hydrogen environment severity assessment method includes a measurement step of measuring the amount of room temperature non-diffusible hydrogen contained in a rolling fatigue region, the rolling fatigue region being a region where rolling fatigue has been produced by rolling contact, within the steel rolling member of the rolling device operated under the operating conditions and an assessment step of assessing the hydrogen environment severity, based on a measurement result in the measurement step.