Welding AISI 4130 1

[STH2561971]

Can anyone advise,

We have recieved a 9" shaft forged from AISI 4130. Hb values of 217 - 237 were specified in the order. Unfortunately on arrival the shaft hardness values ranged as high as 275 Hb. When this is welded in place (will be welded to 12mm S355K2G33 plate in 4 different positions) will I suffer from a higher risk of weld cracking, if so is there any heat treatment I could use to reduce the residual Hb level to a more manageable level.

Thanks for any assistance

 

[metengr]

Based on the information you provided, I don't believe you are at higher risk of cracking provided you use preheat.

Several questions;
1. Is the weld joint design a fillet weld?

2. What is the weld process and filler metal?

 

[STH2561971]

Thanks very much for the help metengr,

To answer your questions,

The welded joint will be a full pen MIG weld, using SF3AM welding wire.

If it is necessary we will try to locally heat treat the welded region however we have to be careful as the shaft is in a finished machine condition and there is a worry of both deformation and scale formation on the finished surfaces.

Thanks
Stuart

 

[metengr]

STH2561971;
Make sure you preheat the shaft to at least 150 deg C and hold the preheat for the duration of welding. Your PWHT should be 1200 deg F for a full penetration weld – time based on the nominal thickness of the weld NOT the diameter of the shaft.. To reduce distortion, upend the shaft and wrap the circumference with resistance heaters to assure a uniform band of heat.