Martensitic stainless steel usually contain up to 0.6% carbon. This carbon added to the alloys to change Fe-Cr diagrams. The carbon content of these hardenable steels affects forming and welding. To obtain useful properties and prevent cracking, the weldable martensitics usually require preheating and postweld
5.7. Name the four alloying elements that have the greatest effect on the properties of steels. Boron improves harden ability, without the loss of (or even with some improvement in) mach inability and formability. Calcium deoxidizes steels, improves toughness, and may improve formability and merchantability. Carbon improves harden ability, strength, hardness, and wear resistance; it reduces ductility, weldability, and toughness.
Increasing carbon content increases hardness & strength & improves hardness . But carbon also increases brittleness & reduces ductility because of its inclination to form martensite . This implies carbon content can be both a boon & a curse when commercial steel is cocerened . & there are steels that have up to 2 % carbon content, they are the
these are stainless steel that a prescription hardenable (PH) such as 15-5PH, PH-13-8Mo and 17-4PH these alloys are used for forging. The alloys include Cr-Ni in their make-up, like austenitic materials. They have added metals such as aluminium, copper, titanium and columbium when other properties are required. These allow the stainless steels to be solution treated and age cycled, giving the material more strength. These materials, when in the annealed condition, are “soft martensitic” and are then made into “hard martensitic” by sub-zero cooling or age cycling.
3.5 Aeration Aeration for iron helps oxidation of certain substances. Also it can increase the agitation of iron to reduce the possibility of agglomeration and facilitate removal of passive film, which is deposited on the surface of iron, improving the effect of flocculation. However, excessive aeration will also affects contact time resulting in lower removal. Aeration can provide more sufficient oxygen to promote the anode reaction under neutral conditions. On the other hand it can accelerate the electrode reaction with stirring and shaking which decreased concentration polarization.
The harder alloy can replace the use of another metal that does not have the required and ideal characteristics for a particular function. 2. Alloy of Iron: Mild Steel Alloy of Copper: Cupro-nickel Composition Mainly of iron with < 0.2% carbon. 70% copper and 30% nickel Use To make car bodies Seawater Pipe work Why alloying the metal makes it more suitable for the use. By adding carbon, the steel becomes harder and stronger and is more corrosion resistant than iron.
Increasing productivity of any welding process while maintaining or even improving the weld quality has been the task of researchers in the field of development of welding processes. Over the years welding methods and techniques have developed to great extent . Now it is feasible to weld starting from thin metal sheets of fraction of mm to very thick plates of virtually any thickness. The quality of welding is not restricted only to work done by the welder but depends on many other factors, viz. welding technique and its parameters, welding equipment shielding medium, working environment, etc.
1. INTRODUCTION Diffusion Surface hardening (DSH) is a popular technique used to enhance the surface properties of the steel by adding the atoms of carbon, nitrogen, boron or combination of the mating surface. DSH gives a hard outer case with a soft tough core. The increased hardness of outer case improves the wear resistance of the steel part which in turn improves the service life of the part. Carburizing is one of the commercial and extensively used surface hardening techniques in engineering industries for its simplicity and cost-effectiveness.
Hastelloy® C-22 alloy has a Critical Pitting Temperature greater than 140˚C whereas stainless steel type 316L only has a Critical Pitting Temperature of 15˚C. This shows that C-22 is a far better at resisting corrosion at higher temperatures than its Stainless Steel counterparts. The same applies to C-276; which is due to them containing a higher composition of carbon and molybdenum than that of Stainless Steel, Mild Steel and Iron. A specific advantage of C-22 is that it can be easily welded. C-22HS has the same resistance as C-22 but it has double the yield strength.
Oxyhydrogen gas which was produced by electrolysis is then injected into vehicle 's air intake system as a supplemental fuel. Oxyhydrogen gas has proven to increase mileage, improving power and lowering emissions. Providing Oxyhydrogen is better than providing pure Hydrogen since Oxygen is mandatory for combustion which is present in Oxyhydrogen. Adding Oxyhydrogen causes gasoline or diesel to ignite faster and more efficiently, resulting in higher FUEL ECONOMY and dramatically LOWER EMISSIONS. Over 60% of the gasoline is wasted through fumes, vibration, evaporation and unburned fuel.