Type of weapon
From UESP wiki's "Thane of Hjaalmarch" article (emphasis mine):
The reward, the Blade of Hjaalmarch, is a random, leveled, enchanted sword. There is a 50% chance that it will be a sword (one-handed), and a 50% chance it will be a greatsword (two-handed). Due to a bug*, however, maces are also occasionally awarded.
*The list for enchanted iron swords that do stamina damage contains only maces. (This bug is fixed by version 1.2 of the Unofficial Skyrim Patch (original / Legendary Edition - PC) / (Special Edition - PC) / (PS4 / PS5) / (Xbox One / Xbox Series X/S).)
Related USKP patch note:
USKP v1.2 - (2012-09-01)
Leveled list SublistEnchIronSwordStamina was populated by maces and has been corrected. This will also cascade to fix various quests that may have called this list as a reward. (Bug #390, 197)
Material
The probability of getting a Blade of Hjaalmarch of a particular material is detailed in the table below. It shows what material is added to the list of possible materials at which level. This means that if the player character is at level 20, then every single material added at levels 1, 2, 3...20 are on the list, not just the material(s) listed at level 20.
Level |
Material |
1 |
3 × Iron |
4 |
1 × Steel |
5 |
1 × Steel |
6 |
1 × Steel |
7 |
1 × Orcish |
13 |
1 × Dwarven |
20 |
1 × Elven |
28 |
1 × Glass |
37 |
1 × Ebony |
47 |
1 × Daedric (5%), Any other material (95%) |
Source: UESP wiki's "Skyrim Leveled Lists - Enchanted Weapons" article
Enchantment
The Blade of Hjaalmarch's enchantment will depend on the player character's level and the weapon's material. The possible enchantments and at which level you will get them are detailed in the tables below. (Click the image to view the larger, original version.)

Source: UESP wiki's "Skyrim Leveled Lists - Enchanted Weapons" article