Method and apparatus for evaluating damage of metal material

A damage evaluation method of a metal material for evaluating a flaw in a metal sample of the metal material, comprising the steps of:

• mounting onto a surface of the metal sample which internally includes the flaw and on both sides of the flaw a transmitting probe for transmitting ultrasonic waves and a receiving probe for receiving the ultrasonic waves;
• transmitting the ultrasonic waves towards the internal flaw and receiving a diffracted wave from the internal flaw for determining whether the flaw is present in the metal;
• carrying out a metallographical analysis for the surface of the metal;
• estimating a degree of progression of creep damage;
• extracting crack propagation data from the thus estimated degree of progression of creep damage and from a predetermined relationship between the progression degree of the creep damage and a creep crack propagation rate of the metal;
• and
• determining a remaining life of the metal material including the flaw,
• wherein it is determined whether the flaw is caused by the creep by the result of the metallographical analysis after carrying out the metallographical analysis of the metal surface in which the internal flaw is present.

A damage evaluation method of a metal material for evaluating a flaw in a metal sample of the metal material, comprising the steps of:

• mounting onto a surface of the metal sample which internally includes the flaw and on both sides of the flaw a transmitting probe for transmitting ultrasonic waves and a receiving probe for receiving the ultrasonic waves;
• transmitting the ultrasonic waves towards the internal flaw and receiving a diffracted wave from the internal flaw for determining whether the flaw is present in the metal;
• conducting chemical analysis of a test sample taken from the surface of the metal;
• estimating creep characteristics of the metal based on results of the chemical analysis;
• carrying out stress analysis based on the creep characteristics;
• and
• determining whether the flaw is generated due to the creep based on the stress analysis.

A damage evaluation method of a metal material for evaluating a flaw in a metal sample of the metal material, comprising the steps of:

• mounting onto a surface of the metal sample which internally includes the flaw and on both sides of the flaw a transmitting probe for transmitting ultrasonic waves and a receiving probe for receiving the ultrasonic waves;
• transmitting the ultrasonic waves towards the internal flaw and receiving a diffracted wave from the internal flaw for determining whether the flaw is present in the metal;
• conducting chemical analysis of a test sample taken from the surface of the metal;
• estimating creep characteristics of the metal based on results of the chemical analysis;
• carrying out stress analysis based on the creep characteristics;
• determining whether the flaw is generated due to the creep based on the stress analysis;
• extracting crack propagation data suitable for the metal material from the results of the chemical analysis and a predetermined relationship between an elemental concentration and a crack propagation rate of the metal;
• and
• determining remaining service life of the metal material including the flaw.

A damage evaluation apparatus of a metal material for evaluating a flaw in a metal sample of the metal material, wherein the damage evaluation apparatus for evaluating the flaw in the metal material comprises:

• a creep damage estimation device for estimating a progression degree of creep damage based on a result of a metallographical analysis of a surface of said metal sample;
• a crack propagation data extracting means for extracting crack propagation data including a distance of the flaw to the surface of the metal suitable for said metal material from the thus estimated progression degree of the creep damage and from a relationship between a predetermined progression degree of the creep damage and a crack propagation rate including a time period for a crack to reach the surface of the metal;
• and
• a remaining service life estimation device for estimating a remaining service life of said metal material.