Sunday, May 27, 2012

Metals - Metallurgy of Welding - Style Down and Dirty

Metallurgy is the study of metal. Welding Metallurgy is the study of how welding affects the microstructure of the metal.

Did you know that there are metallurgists who dedicate their lives to just study the carbon steel? So what about all the other metals such as stainless steel, nickel alloys, aluminum, magnesium, titanium, cobalt, and copper alloy?

Metallurgy is a subject of deep and mysterious that it takes a lifetime to really understand the carbon steel is much less all the rest.

So if it is a deep subject, what is the chance that welders have sufficient understanding of metallurgy to become a better welder.

There is good news. And is not that I save a lot of money on my car insurance by switching to GEICO.

The good news is that you do not have to know anything about metallurgy. You just need to understand some basic principles.

It is absolutely essential to understand is that the heat of the weld metal influence. It sounds very simple but profound. Why? Because heat affects different metals in different ways.

When you heat a piece of metal becomes red hot, and then satisfy by dipping in a bucket of cold water, what do you think happened? If you answered "harden" your only partially right. Only a few metal hardened by heating and rapid cooling. Most other metals react totally different.

Carbon and low alloy steel such as 4130, tool steel, cast iron, and some 400 series stainless steels hardened by rapid cooling of the red hot temperatures.

But most other stainless steels, nickel alloys, aluminum, magnesium, titanium, cobalt, and copper alloys will actually soften and lose their heat by heating and rapid cooling of the red.

So what does this mean to your welder?

If you do the welding on the 4130 chromoly, you need to know not to speed up or cool the weld will harden.

If you are welding 6061 t6 aluminum, you need to know that the weld area will soften if it gets too hot for too long, and the power will be lost and never come back unless the full heat treatment can be done.

Welding 301 full hard stainless steel is easy to do, but the heat from the weld microstructure recrystallizes hard work and strength and hardness goes right out the window.

304 welding of carbon steel and chromium can lead to bind and form a chromium carbide weld area if it is too hot for too long.

So you get the picture. The heat affects different metals in different ways.

Thursday, May 17, 2012

Welding Takes Turn For The Worst

Someone asked me how I know what to do when the weld takes a turn for the worst? It was after years of teaching experience and you learn to train your eyes and thought about what the problem looks like the weld area. That's the benefit of this course. I can relay to you the benefits you can receive from my years of painful mistakes and the mistakes I have learned not only from my own mistakes but the mistakes of those around me. One video was recently published of the series shows the raw trap I opened the gap welding and metal bevel running the risk of falls on creating what is technically called excessive penetration.

Due to penetration excess of pushing too much metal to the interior surface on the inside of the pipe. This is usually caused from staying too long in one place while welding. The combination is too big a gap and high heat can also attribute to excessive penetration. It is almost a guarantee that young welder at some point will encounter this problem. The way around this is to try our best to fit evenly and bevels pipe inner surface of the pipe.

An even gap all the way around the pipe to make life a lot easier. The problem that I face in the video that you see in the series trap raw surface of the pipe is the hypotenuse. The beveling hand is almost always inferior to the plant or machinery bevel. When two factory bevels that consistently matched the gap and make the track fit is more uniform weld. Since this heat range will not need to be adjusted as the uneven hand bevel.

What happened to me on the raw trap is that the gap is not consistent leading to my keyhole opening up to high heat and a lot of my enemies. The lock and open the end of the pipe was on fire before I could save metal. When this happens if you do not immediately stop and make some kind of adjustment is more than likely you will make some of these things if they might not all. 
  1. Burning bevel pipe and open a gap
     
  2. Leave the rest of the metal in the weld line as you live in a big gap too long trying to fill the crater
     
  3. Lowering the lock you have to gorge created.
     
  4. Withdraw the rod while still welding because the heat is too much to handle right now and by doing that youbcan not leave through the weld and weaken the inner pipe surface.
Either way it goes the thing to do is stop welding. You can turn down the heat slightly to bring the amp is usually 5 to 10 amps depending on your skills and problems. Maybe more, maybe less.

Stop welding pipes and let cool. Do not push the rod into the bevel as much butter and began to jump around more bevel causes less penetration.

The only way to be sure about what you do on the inside of the pipe is to adjust a little, a little welding, then look into the pipe with a flashlight to see what you are doing. Hopefully if the pipe is not completely closed you may be able to look through to see the weld bevel interior. You also may be able to see the weld interior with mirror and light from the outside if the pipe is cut to less than the length or closed.

When a gap opens grind as little as possible. The last thing you want to do is take more than a bevel now. If the pipe is lit in red where you can see it after withdrawing from the key hole and key hole appears to grow then let it cool and resist heat.

I hope this all makes sense. If not you know I'll try to clarify or come from a different angle.

Wednesday, May 2, 2012

Welding Gear and Protective Equipment

Beyond the welding torch and welding equipment to use to do their job, there is also a need for specialized welding gear and personal protective equipment to ensure that welder is safe. There are many things that are important to safety. Here are some of the most important:

Gloves - although you may see some welders who do not use gloves, they are an important part of each welder's clothing. This protects your hands from sparks, burns and electric shock. You can find them in form fitting models that help keep your hands flexible and you can get it lined or unlined. Gauntlet gloves will also protect the wrists and upper arms.

Cloth cap or doo - the two types of terms are used for the same purpose. A do cloth wrap that looks just like a scarf that wraps around the head. A welding cap or doo cloth used to absorb sweat and keep sparks from weld work you. Usually you can get these in various colors and patterns. Most of the hat will protect your ears and your head.

Helmet - welding helmet has multiple functions for your security. It protects the head and face from splashes and provide protection for your eyes from the intense heat flash and flame. You are also protected in some way from smoke inhalation. Some solar power or the dark as a result of exposure to a flame. According to OSHA standards, the helmet shell must be resistant to electricity and heat, and it should be opaque to protect the eyes from light. Cover plate on the outside should be made of polycarbonate plastic because it is the only type of plastic that will protect from UV rays.

Helmets should have a glass lens filter that has a charger that protects you from the light that passes through your eyes. The range of filter # 2 - # 14 with a black helmet as the numbers get higher. It is a matter of choice in terms of how dark you want the helmet filter.

Boots - make sure your shoes fireproof and that they are high tops because they will protect you from sparks. Make sure also that you lace them all the way and put your pants legs into boots. This is the extra precautions that will keep you safe while you are welding.

Respirators - when you are in an environment where ventilation is not good, you need to use a respirator. If they do not give them, they should be able to tell you the type that you need for compliance.

General security measures - Make sure that you wear appropriate clothing when welding. Make sure the clothes are made from 100% cotton or wool weight and tightly woven fabric. This will protect against any open flame and hot metal trigger. Do not wear synthetics because they are flammable.