To get this achievement you need to acquire all eight Iron Lord artifacts through the weekly quest given to you by the Cryptarch at the Iron Lord Temple. This quest is once a week per character. Meaning if you have three characters like I do you can get three perk week, granted if she has three you don't have. Sometimes you'll only get two depending which ones you have and which ones she is selling.
The following artifacts you will need are:
Memory of Felwinter
Memory of Gheleon
Memory of Jolder
Memory of Perun
Memory of Radejast
Memory of Silimar
Memory of Skorri
Memory of Timor
The best place to actually farm these kills is to go to Archon's Forge in the Plaguelands. You will need some Splicer Keys (only if you die) and some Siva Offerings. The Siva Offerings come in three qualities; Green (Uncommon) Blue (Rare) and Purple (Legendary). The higher rarity of the Siva Offering= the difficulty of the event. Green (Uncommon) = Easiest, Blue (Rare) =Normal, Purple(Legendary) =Hard. The Siva Offerings drop from random enemies in the Plaguelands and you can only carry one at a time. It is important to note that you can not transfer them through bungie.net or the Destiny Companion App, you need to transfer it in game. That being said once you do use the Siva Offering, it is possible to pick another one up off the ground from an enemy while you are doing the event, saving you farming later. To get Splicer Keys you need to kill Brood Mothers (specially named Wizards) or Brood Knights (specially named Knights). You can find the Knights spawning in the general area of the Archon's Forge, and the Brood Mother Wizards spawn right where you spawn at the Plaguelands. You only need the keys if you die and you are playing solo and nobody is there to revive you. You will spawn back where you enter the room and a wall will be blocking you from entering, you will need a Splicer Key to get back in.
If you don't have the achievement for completing an event in the Archon's Forge, you'll get that too. You'll also complete a task in your Rise of Iron Record Book if you're looking to complete that, though there is no achievement linked to it.
Archon's Forge is also a great early game method of getting loot if you don't want to do strikes or raids. It's a PvE event where waves of enemies will attack you, usually followed by a boss at the end and another wave or two of enemies.
You have an entire week to get the artifacts you need so take your time. The weekly reset is every Tuesday. It took me about and hour for each artifact so it's very easy to break it up a few days during the week at a time. Like I said I have three characters so I would split it on three different days of the week.
Make sure to attune all the artifacts at the corresponding statue so you are able to equip it just in case.
If for some reason the achievement doesn't unlock right away like it did for me, go to the settings in the game and select "switch profile" and it will bring you back to the main menu. Sign in with your main account and it should immediately unlock like it did for me. Switching characters did not pop the achievement for me.