Portable Hardness Measurement

2009-02-24T14:08:00.007+08:00

Hardness is the property of a material that enables it to resist plastic deformation. However, the term hardness may also refer to resistance to bending, scratching, abrasion or cutting which indicate the material strength.

There are two type of portable hardness method that are commonly used at site namely (i) UCI Method, and (ii) Rebound Method

Using portable hardness tester, component’s hardness can be measured at site non-destructively to estimate the component strength based on a relation between hardness and ultimate tensile strength.

Hardness test can also be done at site to confirm component specification and to verify the selection of material for repair and replace work purposes.

All hardness testing methods require smooth surfaces free of oxide scale, paint, lubricants, oil, plastic coating due to corrosion protection or metal coating for better conductivity.

Surface preparation for hardness test at site shall be done according to relevant standards or test specification requirement.

Hardness measurement at site are based on international code and standard as follow:
a. ASTM E92: Standard Test Method for Vickers Hardness of Metallic Materials
b. ASTM A956: Standard Test Method for Leeb Hardness Testing of Steel Products
c. ASTM A1038: Standard Test Practice for Portable Hardness Testing by the Ultrasonic Contact Impedance Method

Microstructure Preparation by Replication Technique

2009-02-20T12:20:00.016+08:00

The microstructure of a petrochemical plants and critical components of power plants will over time degrade when exposed to high temperature, high stresses and corrosive atmosphere.

One of the purpose of performing in situ replication is to determine the extent of thermal degradation or thermal aging from the microstructure appearance. Prolonged exposure to high temperature will cause microstructures to decompose and eventually result in creep cracking.

By replication technique, microstructure can be obtained at site non-destructively to safely judge the condition of the component. The results obtained can be used to identify previous heat treatment process and to verify the required temperature setting for post weld heat treatment (PWHT) for repair work purposes, and as a reference for future inspection and maintenance work arrangement.

The processes of producing replica at site are based on international code and standard as follow:
a. ASTM E3: Standard Guide for Preparation of Metallographic Specimens
b. ASTM E407: Standard Practice for Microetching Metals and Alloys
c. ASTM E1351: Standard Practice for Production and Evaluation of Field Metallographic Replicas

d. ASTM E1558: Standard Guide for Electrolytic Polishing of Metallographic Specimens

On Site Metallography Services & Failure Analysis

Portable Hardness Measurement

Microstructure Preparation by Replication Technique