When crafting an item, the Odds of Quality are displayed at the bottom of the screen before you commit to crafting. If a percentage is displayed in a rarity's corresponding color, then this means there is a possibility of receiving gear of that quality.
Even if the percentage is high that you will get one quality, anything less than 100% odds will mean there is always a chance of receiving something lower.
The only way to ensure that your item is crafted at a particular quality is to use all of the same quality items in crafting, including the Gear piece broken down.
If you risk using lower-quality materials in your crafting, there is no way to reverse the transaction if you don't get what you were hoping for. However, you can upgrade a piece of Equipment's quality by tapping the blue “Upgrade” button next to any piece of equipment in your Equipment tab of the Smithy. Upgrading requires 3 pieces of similar quality and level equipment to consume.