Welding Test Block with Variable Melt-Thru Spacing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for qualifying welding processes in pressure sensors are often destructive, hazardous, expensive, and time-consuming, particularly when testing weld penetration depth, which can lead to damage and inefficiencies in quality control.

Innovation Solution

A test block is used to simulate a production welding process, featuring a test welding path with a melt-thru surface spaced variably from the welding path, allowing for non-destructive measurement of weld penetration depth and statistical process control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If destructive testing methods are used to qualify welding processes, then measurement precision of weld penetration depth is improved, but productivity decreases and harmful factors increase

Engineering Contradiction:
Improveweld penetration depth measurementVSAvoidquality control efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent uses a test block that replicates the essential geometric features and material properties of the actual workpiece, allowing weld penetration depth to be measured directly on the test block without destructive testing of production parts. The test block includes a surface spaced from the weld by a distance corresponding to the expected penetration depth, enabling non-destructive verification.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The test block serves as an intermediary object between the welding process and the measurement system. It absorbs the harmful effects of repeated testing and provides a safe, reusable platform for qualifying welding parameters, eliminating the need for destructive cross-sectioning and polishing of actual components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If destructive testing methods are used to qualify welding processes, then measurement precision of weld penetration depth is improved, but loss of time increases

Engineering Contradiction:
Improveweld penetration depth measurementVSAvoidquality control cycle time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The test block replicates the critical geometric features of the workpiece, allowing rapid non-destructive measurement of weld penetration depth using surface inspection methods rather than time-consuming destructive cross-sectioning and metallographic preparation.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The test block is prepared in advance with a surface positioned at a predetermined distance from the weld path, corresponding to the expected penetration depth. This preliminary setup enables direct measurement of weld penetration without requiring post-weld destructive analysis of production parts.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If non-destructive testing methods are used to qualify welding processes, then productivity is improved and loss of time decreases, but measurement precision of weld penetration depth deteriorates

Engineering Contradiction:
Improvequality control efficiencyVSAvoidweld penetration depth measurement
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The test block creates a physical copy of the weld-groove geometry with a surface positioned at a known distance from the weld path. This allows non-destructive testing methods to achieve high measurement precision by directly observing whether the weld penetrates to the surface, providing clear pass/fail criteria without the need for destructive cross-sectioning.

Inventive Principle:
Principle #26Copying

4Measurement precision

If destructive testing methods are used to qualify welding processes, then measurement precision of weld penetration depth is improved, but object-generated harmful factors increase

Engineering Contradiction:
Improveweld penetration depth measurementVSAvoidhazardous testing steps
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The test block replicates the essential welding geometry and material properties, allowing all qualification testing to be performed on the test block rather than on actual production parts. This eliminates hazardous destructive testing steps such as acid etching and cross-section cutting from the production environment.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The test block acts as an intermediary that absorbs all hazardous testing operations. Destructive cross-sectioning, polishing, and chemical etching are performed only on the test block, isolating these harmful processes from the production workflow and eliminating the need for specialized hazardous material handling facilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

5Productivity

If non-destructive testing methods are used to qualify welding processes, then productivity is improved and loss of time decreases, but device complexity increases

Engineering Contradiction:
Improvequality control efficiencyVSAvoidtesting equipment requirements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The test block creates a simplified geometric copy of the welding joint with a surface positioned at a predetermined distance from the weld path. This geometric simplification allows basic non-destructive testing methods to effectively measure weld penetration depth without requiring complex imaging or analysis equipment.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables rapid, cost-effective, and non-destructive testing of weld penetration depth, reducing the need for destructive sampling and improving quality control by correlating with previous destructive methods, thus ensuring adequate weld strength without damaging internal components.

Implementation Method 1

a welding process of the work piece

Methodology Applied
Scientific EffectThermal energy: Heating

Implementation Method 2

a melt-thru surface that underlies the test welding path. The melt-thru surface is spaced apart from the test welding path by a spacing that decreases along a length of the test welding path

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP2621665B1Test block for use in a welding process ; method of qualifying a welding process on a production workpiece
Publication Date: 2015.03.04 ROSEMOUNT INC
  • EP2621665B1 patent drawingFigure 1A~1B
  • EP2621665B1 patent drawingFigure 2
  • EP2621665B1 patent drawingFigure 3A~3B

AI summary

A method and test block (400) for controlling weld penetration depth in a work piece (100) are disclosed. The test block (400) simulates a work piece relative to a welding process of the work piece. The test block (400) includes a test welding path (402). The test welding path (402) replicates a production welding path on a weld surface of the work piece. The test block (400) includes a melt- thru surface that underlies the test welding path (402). The melt- thru surface is spaced apart from the test welding path (402) by a spacing (406) that decreases along a length of the test welding path (402). The spacing (406) varies from more than a standard weld penetration depth to less than the standard weld penetration depth.