×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Micrograph of AISI 1045 steel-Segragation and bands in grains

Micrograph of AISI 1045 steel-Segragation and bands in grains

Micrograph of AISI 1045 steel-Segragation and bands in grains

(OP)
Hello everyone,

I have a question about bands and islands found in grains of AISI 1045 steel after heat treatment of:

Austenization (inert atmosphere): At 880 C for 1 hour
Annealing: At 550 C for 1 hour

The chemical composition is: C: 0.45 %wt
Mn: 0.3-0.6 %wt
S: <0.03 %wt
Cr+Ni+Mo: < 0.6 %wt
Si: <0.4 %wt

In this micrograph,
The dark bands (waves) in red box and again dark relatively straight lines in blue boxes.

In this micrograph:

The white islands in grain with red box.

I couldn't figure out what they could be, so I'm asking for your help. If you can give some head-up, I'd appreciate a lot.

Thanks in advance

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

onurct;
Need more background information regarding the micrograph attachments. How was the 1045 steel sample above prepared for viewing? Was a section of the 1045 steel prepared using standard metallograhic techniques? How was the sample etched for viewing?

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

They look like SEM images, probably secondary electron detector.

Nick

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

onurct;
Another question - your stated heat treatment parameters are not typical for 1045 steel. Why was a subcritical anneal done at 550 deg C? Was the material held at 880 deg C to fully austenitize and then cooled to 550 deg C before furnace cooling?

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

onurct,

The white islands in the second image are carbide particles (cementite) that are partially spheroidized. Subcritical annealing of steels with pearlitic microstructures will transform the cementite in the pearlite into a spheroidal form. This transformation is a function of temperature, time, and the amount of strain stored in the material (deformation from prior processing). In order to completely transform all of the cementite into spheroids you would need to hold the sample at temperature for a longer time, or impart more strain on the sample by deformation (drawing rod through a die, etc.).

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

(OP)
Thanks a lot for the responses.

Metengr,

FIB profile cuts and SEM, as NickE said. I dont know why it was done at 550 C. I'll ask. And yes, it was held at 880 C for fully austenitization and cooled to 550 C before furnace cooling.

RE: Micrograph of AISI 1045 steel-Segragation and bands in grains

I think before I would venture any further using the above images, I would perform a metallographic examination of the sample.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources