Need help identifying microstructure. SAE 1212? 1

[GonzaloMartinez]

Hello everyone,
I'm currently dealing with a sample that belongs to a hydraulic quick coupling that had fracture after an external load was apllied due to a lateral pulling of the hose. CQ 0.19 C, 1.10 Mn, <0.0100 Si, 0.11 Cr, 0.195 Cu, 0.087 Ni, 0.028 Mo, [highlight #F57900]0.0965 P[/highlight], [highlight #F57900]>0.15 S[/highlight]. Looks close to SAE 1212 to me, our equipment can´t analyse lead content (12L14?). My first time with this material, I would appreciate some help identifying the phases observed under the microscope.

Forgot to tell that the component was case hardened, so this microstructure was surely heated. The micrographs shown belong to the sample's core. The surface layer exhibits martensite.

250X before etching, huge inclusions (electrolitic polishing)

100X etched with Nital 3%

250X etched with Nital 3%

400X etched with Nital 3%

 

[CoryPad]

Looks like 12L14 to me. In the first micrograph, the long gray inclusions are manganese sulfide. The small black dots are lead. The rest is ferrite and pearlite. See the attached images I took from a part made with 12L14.

 

[GonzaloMartinez]

Thank you CoryPad for your help.
I have search a bit better and I found that the lines sorrounding the black areas (pearlite)that were getting on my nerves might be "ghost structures" due to the phosphorus presence. Here is the source Link

 

[UconnMaterials]

Thanks GonzaloMartinez! Good lunch break read!

UconnMaterials