Preheat is used when a base material, due to its chemical composition, thickness or level or restraint, is susceptible to cold cracking (hydrogen induced cracking). Knowing what temperature to preheat your base metal is sometimes a complicated matter. You may hear people say “preheat to 300F to be safe.” The reality is that 300F may […]
Today we’ll cover 5 more very important concepts that are governed by the AWS D1.1 Structural Welding Code (Steel). If you missed our last post with the first five questions simply click here. These concepts can show up as questions in the Certified Welding Inspector (CWI) Exam. As stated in our article from last week, […]
If you have taken or hope to take the CWI exam you probably have searched for some practice exam questions. In practicing for the code book portion of the test you may have come across a few questions for which you could find the answer, but didn’t really understand the importance of the question or […]
Regardless what position you hold, if you work in the welding industry you have heard of welding procedures specifications (WPSs). To some, a welding procedure simply means the selection of a few variables such as amps and volts. To others, these are the documents that govern all welding done in their facility. A […]
As discussed in our previous article, and many times in the last 50 or so, preheat is necessary in steel welding to control the cooling rate. More specifically, preheat is used to slow the cooling rate down in order to prevent excessive hardness in the heat affected zone (HAZ) which can lead to cracking. Before […]
Our next article will discuss a question we are asked quite often: Can we eliminate preheating before welding? Preheating is necessary to slow the cooling rate down after welding which in turn avoids excessive hardening of the weld and heat affected zone. Eliminating preheat can lead to hydrogen induced cracking and catastrophic failure. A […]
Preheat is necessary in certain carbon and low alloy steel applications to prevent hydrogen induced cracking, also known as cold cracking. Cold cracking susceptibility increases as the amount of carbon in steel and the thickness go up. The higher the carbon content the easier it is for the steel to harden. And, the thicker the […]
High carbon steels are those containing 0.45% carbon or higher. They are typically considered “hard to weld” because they are crack sensitive and are susceptible to undergoing significant changes in their physical and mechanical properties after welding. However, high carbon steels can be welded successfully and without problems by having a sound understanding of the […]
Abrasion resistant (AR) steel plate is used in applications requiring abrasion and impact resistance. It is alloyed with high levels of carbon in order to attain high levels of hardness through the quenched and tempered process. AR plate is primarily used in conveyors, buckets, dump liners, construction attachments, grates, body armor and ballistic plates. AR […]
It is often incorrectly assumed that quenched and tempered (Q&T) steels are hard to weld or even completely unweldable. This assumption is inaccurate as most Q&T steels have great weldability. However, extreme care must be taken to prevent cracking or loss of certain mechanical properties. A very common quenched and tempered steel is ASTM A514. […]
