Strength, hardness, and durability are three factors that make steel plates an essential component in iron gates.
Iron is vulnerable to moisture. It can corrode easily in a few years if it comes in contact with water for long periods.
But iron gates coated with steel would not corrode. Heat treating steel is the ideal process to produce steel gates and fences for homes.
The heat treatment process goes through different stages and the temperature to treat the steel also changes accordingly.
Usually, SAE 4140 steel plates undergo three different stages of heat treatment:
• 1550 to 1600o F during first oil quenching
• 1500 to 1600o F during second oil quenching
• 1475 to 1525o F during third oil quenching
For steel tempering, the temperature should vary between 500 and 600° F and 800 to 900° F at different stages.
Heat treating steel involves a systematic process that starts with heating, followed by altering the physical properties of the plates, and ends by cooling.
Here is an in-depth analysis of what happens in a heat treatment process while coming up with fancy steel gates design.
In this process, the experts place the steel plates inside a furnace.
The temperature inside the furnace is very high so that it can bend plates easily of up to 1″ thickness.
It usually takes around one hour for the furnace to change the physical properties of the plate. Next, the plates are taken out and kept at room temperature.
The high temperature inside the furnace alters the plates’ grain structure, ductility, strength, machinability, and hardness, making the plates ideal for a modern steel gate design.
Normalized steel plates are appropriate for various applications like bridges, pressure vessels, bridges, and buildings. They become extremely strong and durable after the first stage of heat treatment.
This is the second stage of heat treatment.
Annealing is almost similar to normalizing but only differs in its cooling process.
You put the steel plates inside the furnace and wait for the heat to change its physical properties.
Once the plates start changing their shapes, you need to put them in a chamber at below-critical temperature. Annealing involves treating the steel plates in a controlled heating and cooling unit.
This type of controlled heating and cooling changes the plates’ grain structure, thus increasing its ductility but reducing its hardness. With enhanced ductility and strength, annealed steel plates are mostly used to support normalized steel gates.
Quenching and tempering is a two-fold heating and cooling process.
Quenching involves heating the steel plates between 1,500 and 1,650o F.
You need to quickly put the plates in ice-cold water to bring its temperature down. You will again need to put the plates in a furnace and heat them at around 300 to 700o F.
Next, you need to cool the plates at room temperature.
This is the tempering part that changes the grain structure and makes the steel plates tough and hard. They become ideal for steel gates and fences in your house.
This stage also involves heating and cooling the iron plates in two steps.
In the first step, the steel plates go into a furnace that has a temperature between 1,000 and 1,300o F, followed by rapid cooling in ice-cold water.
In the next step, the plates undergo a process called age hardening, followed by cooling them at room temperature.
This process increases the toughness and strength of the plates, making them ideal for producing guard rails and fences around homes.
Steel plates have a very high density that makes them challenging to bend.
But treating them between 1550 to 1600o F for nearly one hour is more than enough to change their physical structures.
Oil quenching is highly popular in steel plate treatment because of its severity. Compared to water, it transfers heat quickly through different media like gas or molten salt.
Normalizing heat treatment is most common for steel plates used for gates and fences.
The steel plates undergo heat treatment inside a furnace, followed by cooling them at room temperature to increase their ductility and strength.
Crescent City Iron Works is one of the leading companies in New Orleans that offers iron and steel gate designs for your house.
Our iron gates designs can be customized and our steel plates provide strength and durability.
Contact our New Orleans office today to set up an appointment so that we can show you some of the exclusive iron plate gate designs.