types of steel

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I'm a new member here and I have some questions.1) What is the difference between hot rolled and cold rolled steel and the characteristics of both;2) Is heat treated steel weldable?  An example being a cutting edge on a loader bucket; a corner of the cutting edge snapped off, area was cleaned then fragment welded but broke off with mild force applied.  As a novice welder, I did not know it was treated as after grinding it looked the same as mild steel.Thanks in advance for any replies.
Reply:Originally Posted by devilswincupI'm a new member here and I have some questions.1) What is the difference between hot rolled and cold rolled steel and the characteristics of both; Is this regarding the bucket? http://www.google.com/webhp?hl=en#hl...ceae67f006966a2) Is heat treated steel weldable?  An example being a cutting edge on a loader bucket; a corner of the cutting edge snapped off, area was cleaned then fragment welded but broke off with mild force applied.  As a novice welder, I did not know it was treated as after grinding it looked the same as mild steel. There are lots of folks on the board with bucket repairs under their beltThanks in advance for any replies.
Reply:The hot and cold rolled is a seperate question.Maybe I should use the search function, but i will describe anyway.  The bolted on cutting edge was damaged this past winter during snow removal.  The right corner of the bucket got hooked on a curb and a 4 inch piece of the cutting edge snapped off.  Not understanding the nature of treated steel at the time, I stick welded the fragment back to the cutting edge using 6010 root and 7018 over it.  I tested it by driving the bucket into a hard object at low speed and it snapped off like a twig.
Reply:Thanks for the link, answered my first question.  Don't know why I didn't do that myself.
Reply:Originally Posted by devilswincupThanks for the link, answered my first question.  Don't know why I didn't do that myself.
Reply:As far as heat treated steel the answer to whether it can be welded is maybe.Often for those types of steel special weld proceedures are called for, preheat, postheat, special high strength wire/rod  and so on. Also it's not unusual to have to watch how hot you get the steel so as not to draw out the heat treatment.That said your cutting edge may not be heat treated, but simply high carbon hardened steel. Often edges are made from AR type (abrasion resistant) ot T1 type (impact resistant ) steels rather than something that is heat treated. Again usually there are specific procedures used to weld these steels. When I get a weld on edge or tooth shanks, I ask my supplier what weld procedures are specified for that particular material. Often it's not complicated, preheat, weld with 70 or 80 series wire/rod and cool slowly. These procedures can be different from those a friend uses to weld on actual heat treated alloys used for crane booms, especially the wire/rod.My guess is that the reason the edge snapped is that you failed to preheat/post heat the edge and the grain structure of the material was altered. This caused a brittle area that failed. Also I've never had a 60 series rod recomended for an edge. The suggestion is almost always for a low hydrogen rod like 7018 or possibly 8018 in stick, or 70 or 80 series solid wire. Usually I don't find it practical to repair a broken edge, it's cheaper to replace it. That said, I've welded up plow edges with mixed results, usually in a storm under less than ideal conditions to get thru the storm, or to prevent damage to the blade until we can get the replacement. One thought is that they sell edges often in sections. You might be able to buy a 1/3 or 1/2 edge and then cut the remains of the existing one to match and save some money..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan