683
As for HT2 , the microstructure of heat affected zone was composed of B2 + α2 + rim-O + primary O + acicular O in the region close to the base metal , B2 + intergranular α2 + transformed O + primary O + acicular O in the region close to the fusion zone .
 material: As; concept or principle: microstructure; concept or principle: heat affected zone; material: O; material: O; material: base metal; material: O; material: O; material: O; concept or principle: fusion zone
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: As; concept or principle: microstructure; concept or principle: heat affected zone; material: O; material: O; material: base metal; material: O; material: O; material: O; concept or principle: fusion zone