ASTM A 656 to 1018

By BigMan Date 09-15-2017 04:00

Has anyone ever attempted to weld ASTM A656 Base metal to ASTM A1018 Base metal? Recently I have been welding a PQR for a CWI using the 2 different base metals with .052 Wire and 95, 5 Gas. its just a 1G on 3/8in plate but every time the weldment goes to X-Ray it shows a lot of porosity. 3 times in a row. i know for sure that there is not a draft in the shop the gas flow is at a constant 40 CFH, correct pre-heat and interpass temps and the steel in clean.

Any help would be greatly appreciated.

By 803056

Date 09-15-2017 11:32

ASTM A656 can have a minimum specified tensile strength of 90 ksi, so the strength is dependent on the grade specified by the designer. Likewise, ASTM 1018 HSLA steel can have a maximum specified UTS of 90 ksi. The chemistry will vary from one UTS to another.

Your problem, i.e., porosity, is usually related to one or multiple contributing factors:

1) surface contamination (unless you are welding to D1.1 where that apparently isn't that important (sarcasm))
2) insufficient deoxidizers in the filler metal. Select a filler metal that is more highly deoxidized.
3) insufficient shielding gas flow or too much depending on the nozzle diameter.
4) wrong shielding gas (95/5 doesn't tell us what gas is being used.)
5) The distance between the gas nozzle and the work piece could be incorrect
6) Are you using GMAW solid filler metal or FCAW electrode and what is the classification?
7) Incorrect welding parameters. What are the welding parameters recommended by the manufacturer? Voltage, wire feed speed, electrode extension must be controlled. Setting the parameters by the seat of the pants is often the root cause of many weld related problems.

Remember: good, detailed information usually receives more detailed responses.

Good luck - Al

By BigMan Date 09-15-2017 17:33

Thanks, I'm using 95% argon with 5% Co2. i was running 300IPM and 25.6 Volts. filler was ER70s6 .056

By jwright650 (*****)

Date 09-15-2017 18:15

What was your ESO? (stickout)
Stick out can effect your gas coverage and voltage. (too much, too little)
1/2" to 3/4" is pretty typical

Data sheets:
Lincoln's L-56 .052" with 90/10 CO2: ESO 1/2" to 3/4", 300ipm to 485ipm, voltage 30-32
Lincoln's L-59 .052" with 90/10 CO2: ESO 3/4", 300ipm to 485ipm, voltage 30-32