Marine Welding

In marine applications heavy duty 316 stainless steel is often used in order to provide enhanced corrosion protection & strength in warm salt water environments. Stainless Steel Marine Welding : Parts And Equipment Aft handrails Anchor accessories Anchor rollers Arches Bimini framing, grab rails &  hardware Bollards Boom gallows Bow rails Bridge rails Cabinet hardware … Read more

Machine Shop: Making a Layout

Planning before beginning any layout is one of the most important steps. Each job may require different layout tools depending on the accuracy needed; however, there are certain procedures that should be followed in any machine shop layout. Study the shop drawing or blueprint carefully before you cut off the stock. Allow enough material to … Read more

Hardening of Steel

Hardening of plain carbon steel is done by heating it above the critical temperature and cooling it rapidly by plunging it into the water, iced brine, or other liquid. When heating through the critical temperature range, iron undergoes a transformation and changes from a form with low carbon solubility to one with high carbon solubility. … Read more

Tempering of Steel

After a steel is hardened, it is too brittle for ordinary purposes. Some of the badness should be removed and toughness induced. This process of reheating quench hardened steel to a temperature below the transformation range and then, cooling it at any rate desired is called tempering. The metal must be heated uniformly to a … Read more

Machine Shop Work

Machine shop work is generally understood to include all cold-metal work by which an operator, using either power-driven equipment or hand tools, removes a portion of the metal and shapes it to some specified form or size. It does not include sheet metal work and coppersmithing. Machine Shop : Laying Out Work “Laying out” is a … Read more

Oxygen And Oxygen Production

a. *** Oxygen*** is a colorless, tasteless, odorless gas that is slightly heavier than air. It is nonflammable but will support combustion with other elements. In its free state, oxygen is one of the most common elements. The atmosphere is made up of approximately 21 parts of oxygen and 78 parts of nitrogen, the remainder being … Read more

Heat Treatment Of Steel

Heat treatment of steel may be defined as an operation or combination of operations that involve the heating and cooling of the metal in its solid state in order to obtain certain desirable characteristics or properties. Metal and alloys are primarily heat-treated to increase their hardness and strength, improve ductility, and soften them for later … Read more

Controlling Contraction In Sheet Metal

In order to control contraction in sheet metal, the welding procedure should be devised so that contraction stresses will be held to a minimum order to keep the desired shape and strength of the welded part. Some of the methods used for controlling contraction are described below. b. The backstep method as shown in view A, figure 6-43, … Read more

In-Service Cracking

In-Service cracking, due to stress corrosion, hydrogen embrittlement, and corrosion fatigue are typical of material/environment interactions that are not fully accounted for in the ASME (*American Society of Mechanical Engineers) *Code design rules. In welding, the HAZ (Heat Affected Zone) contains a potentially crack susceptible metallurgical structure, hardness variations, and residual stresses that can promote various types … Read more

Weld Failure Analysis

Weld Failure Analysis. Only rarely are there failures of welded structures, but failures of large engineered structures do occur occasionally. Catastrophic failures of major structures are usually reported whenever they occur. The results of investigations of these failures are usually reported and these reports often provide information that is helpful in avoiding future similar problems. … Read more