What is welded manufacturing?

Welding is a manufacturing method used in industry to combine a number of materials with each other. Generally, welding method is used for joining metal or thermo plastic materials. In principle, the part of the material to be welded is melted first and the filling material is placed in this part. This point is then cooled to harden. In another welding method, the heat bonding process is carried out under a certain pressure.

A wide range of energy sources such as electric arc, gas flame, laser, electron beam or ultra sound waves can be used for welding. In industry, welding works are carried out with different methods in different environments such as open air, underwater or space gap. However, wherever and in what way the welding works are carried out, there are various dangers. According to the welding method used, protection from flame, electric shock, toxic fumes or ultraviolet rays is required.

Until the late nineteenth century, the blacksmiths used only welding and welding methods in which metals were joined by heating and forging. Oxygen gas welding or electric arc welding methods began to be used with the beginning of the twentieth century. At the beginning of the twentieth century, especially during the first and second world wars, the need for resources has increased and resource technology has developed rapidly and more reliable and cheaper methods have been found.

After the wars were over, the more modern methods of welding technology were introduced: manual methods (such as manual metal arc welding) and semi-automatic and automatic methods (such as gas arc metal arc welding).

In the second half of the twentieth century, laser beam welding and electron beam welding methods were found and started to be used. Today, with the development of technology, developments in welding technology continue. In fact, robot welding is also widely used in industry today.

Today, research and development efforts are underway to improve welding quality and properties and to reduce welding costs.

The most important point in welded manufacturing is health and safety measures. During welding activities, dust, fumes and gases which may adversely affect the health of the welders are emitted. Employers must take adequate health and safety measures to protect resource workers from these harmful substances. For this purpose, working areas should be free of harmful substances and depending on the welding materials used, welding method and application conditions, and employees should be provided with fresh air. In this regard, employers must ensure that hazardous substances are expelled from the point of origin and that the necessary ventilation conditions are met.

ISO 3834 Welding Management System What Is It?

From simple constructions to constructions carrying risks, welding is an important part of its manufacturing in many products such as buildings, steel structures, bridges, pipelines, cranes, ladders, pressure vessels, conveying and lifting equipment, and welded manufacturing quality is a critical factor in these systems.

The quality of the products used in the production of welding should be ensured during production, not by subsequent examinations. In order to obtain quality products, necessary controls should be made during the material selection and production stages starting from the design stage. If the design of a product requiring welding is made incorrectly, serious and costly problems may arise during production. Even if the design is done correctly, the wrong material selection or welding conditions are not sufficient, welded joints may cause subsequent cracks. Therefore, in order to ensure reliable and reliable production, there is a need for prior knowledge of the problematic situations and the application of appropriate quality procedures.

Therefore, many standards have been developed in order to ensure the quality of welded products. These standards generally focus on the welding method and the properties of the connection. What is essential is the assurance of quality and the protection of customers.

The first published standard is the EN 729 standard. This set of standards defines the quality criteria for arc welding of metallic materials. In 1994, the European Committee for Standardization (CEN) published the following set of standards:

• EN 729-1 Quality requirements for welding - Fusion welding of metallic materials - Part 1: Selection and application guidelines
• EN 729-2 ... Section 2: Comprehensive quality requirements
• EN 729-3 ... Section 3: Standard quality requirements
• EN 729-4 ... Section 4: Basic quality requirements

The EN 729 standard range has been used by businesses until recently.

On the other hand, in the year 1994, the ISO 3834 standard series was also published by the International Standards Organization (ISO). ISO 3824 standard and EN 729 standard were similar in scope. This standard is the guide to the enterprises for welding works in metallic manufacturing enterprises.

The International Standards Organization and the European Standardization Committee came together in 2005 and agreed to publish the ISO 3834 Welded Manufacturing Management System standard. In our country, Turkish Standards Institute is based on ISO standards and published as follows:

• TS EN ISO 3834-1 Quality requirements for the melting of metallic materials - Part 1: Criteria for selecting the appropriate level of quality requirements
• TS EN ISO 3834-2 Quality requirements for melting of metallic materials - Part 2: Comprehensive quality requirements
• TS EN ISO 3834-3 Quality requirements for melting of metallic materials - Part 3: Standard quality requirements
• TS EN ISO 3834-4 Quality requirements for the melting of metallic materials - Part 4: Basic quality requirements
• TS EN ISO 3834-5 Quality requirements for the melting of metallic materials - Part 5: Documents required for the verification of ISO 3834-2, ISO 3834-3 or ISO 3834-4 standards

The ISO 3834 standard became widespread soon after publication. The European Union directives also refer to the ISO 3834 standard.

EN 15085 Welded Manufacturing Qualification What is Management System?

The EN 15085 standard is also a series of standards by the European Committee for Standardization which includes the criteria for production, overhaul and maintenance of railway vehicles and parts. The principles of this standard apply to the production and maintenance of railway vehicles and parts, and to the welded manufacturing of metal materials. Welding studies are defined as special methods for these processes. The requirements for this method are in the ISO 3834 standards described above.

The EN 15085 standards in question are:

• TS EN 15085-1 Railway applications - Welding of railway vehicles and components - Part 1: General
• TS EN 15085-2 Railway applications - Welding of railway vehicles and components - Part 2: Quality specifications and certification of welding manufacturers
• TS EN 15085-3 Railway applications - Welding of railway vehicles and components - Part 3: Design specifications
• TS EN 15085-4 Railway applications - Welding of railway vehicles and components - Part 4: Manufacturing requirements
• TS EN 15085-5 Railway applications - Welding of railway vehicles and components - Part 5: Inspection, testing and documentation

Welded manufacturing qualification certification studies are carried out in accordance with EN 15085-2 standard. Businesses are certified under four certification levels within the scope of this standard. Certification levels are determined by production capacities and performance status of enterprises:

• CL1: Railway vehicles and vehicle parts with high quality class weld seams (this level covers the manufacture of the whole vehicle)
• CL2: A sub-class quality level for the production of boarding gates, roof fittings and similar parts other than the main components
• CL3: Basic equipment parts for the production of railway vehicles (this level includes manufacturing with quality level CP D)
• CL4: Enterprises that do not produce welded but design, purchase and install or purchase and operate railway vehicles and vehicle parts

Is the ISO 9001 Standard Sufficient for Welded Manufacturing?

In fact, the ISO 9001 Quality Management System standard is capable of being installed and implemented in businesses of all sizes operating in various sectors. In this respect, ISO 9001 certificate can also be obtained in the enterprises producing welded products. However, in welded manufacturing, the product quality of the finished products cannot be determined by subsequent tests. Welded manufacturing is a very special process, and certification systems specific to welded manufacturing activities play a very important role in achieving quality and protecting customers. Because there is a need for activity-specific control processes that require technical knowledge and experience. As such, the ISO 9001 standard is not sufficient to determine the correct application of welded manufacturing processes. In order to ensure the quality of welding work, it is necessary to keep constant control before, during and after production.

Today, welded manufacturing companies generally use two different welding methods, depending on whether the heat or pressure effect plays a major role. These methods are melt welding and solid state welding. When melt welding is performed, the parts to be joined are joined by melting using an additional filler metal, as is the case for its back-welding. In solid state welding, the parts to be joined are joined by heat or pressure support. This second method does not use an additional metal and does not involve a melting process. Blacksmith welding or diffusion welding are examples of this method.

The ISO 3834 Welded Manufacturing Proficiency Management System standard mentioned above has been designed to determine the appropriate quality conditions in the activities of welded manufacturing enterprises in accordance with the melt welding method.

This standard specifies detailed quality criteria for the fusion welding of metallic materials used in indoor or outdoor areas of enterprises. Although this standard is a quality standard and is based on the ISO 9001 standard, it alone is insufficient in manufacturing activities based on the general criteria of the ISO 9001 standard.

What EN 15085 Standard Provides?

The EN 15085 standard is a standard that has been developed in lieu of the DIN 6700 standard series published for the railway sector. It demonstrates that enterprises operating in the railway sector have full control over their welding processes and produce at the quality level that customers require.

In accordance with this standard, the welding method, material group and welding material used in welded production must be compatible with each other. Businesses need a report that shows that resources are made in accordance with the relevant standards in the project requirements, mechanical tests are performed and the results are reliable. Therefore, each welding instruction must have a welding method test approval report supporting it. These tests should be conducted under the supervision of independent control bodies (surveillance companies) and approved.

The standards considered in the validation of welding methods are:

• TS EN ISO 15610 Specification and specification of welding procedures for metallic materials - Characterization based on tested welding consumables
• TS EN ISO 15611 Specification and specification of welding procedures for metallic materials - Characterization based on previous welding experience
• TS EN ISO 15612 Specification and specification of welding procedures for metallic materials - Characterization by adopting a standard welding procedure
• TS EN ISO 15613 Specification and specification of welding procedures for metallic materials - Qualification based on pre-manufacture welding test

• TS EN ISO 15614 Specification and classification of welding procedures for metallic materials - Welding test procedure

During manufacturing welding tests, the adequacy of the design according to EN 15085-3 standard is checked as follows:

• To ensure welded manufacturing
• To meet welding conditions
• To see the adequacy of welding elements
• To see the quality of the source product

These tests must be performed under the same conditions as the actual product.

EN 15085 standard series includes general requirements for welding of railway vehicles and parts and increases the competitiveness of enterprises in the railway sector in national and international market. In order to be able to export railway vehicles, their parts and services related to these products to European Union countries and to be taken into consideration in the tenders to be opened in our country, the enterprises that will operate in these fields must be documented.

Within the scope of TS EN 15085-2 standard, after passing the necessary audits, TS EN 15085 Welded Manufacturing Qualification Certificate is issued and delivered to the enterprise. The validity period of this document is maximum three years. In case of any change in the information contained in the document, the enterprises should notify the relevant certification body and ensure that the necessary arrangements are made. In addition, it is necessary to conduct interim inspections at least once a year during the validity period of the certificate and to prove that the standard requirements continue to be met.

The benefits of the TS EN 15085 standard to the enterprises are as follows:

• Welded manufacturing works are carried out in compliance with the relevant quality standards
• The welding quality requirements of ISO 9001 standard are fully met
• More resource-related activities are coordinated more efficiently
• Improper welding reduces the amount of unsuitable products
• Reduces repetitions, repairs and repairs during activities
• New technologies are used more effectively and efficiently
• Reduced product costs per piece
• Customer satisfaction is raised
• Reduces possible recalls and fewer customer complaints
• The reputation of the business increases and the business gains the status of a top-class supply company
• Superiority over opponents
• Activities are carried out more effectively and business recognition increases in domestic and international markets
• Enables the company to participate in domestic and foreign tenders
• Export opportunities increase
• Obtain clear and independent verification in accordance with TS EN 15085 standard
• Increases production capacity
• Employees gain independent qualification approval
• Reduces the need for audits of customers or representatives
• Expenditure on independent audits decreases

businesses Certification according to EN 15085 Standard

In the production of railway vehicles and equipment, their working life strength and their ability to work under dynamic loads are important points. Therefore, welding technology is very important in production. For this reason, in the production and manufacturing process of railway vehicles, the following processes must be in accordance with EN 15085 standard and welding technology and should be evaluated well:

• Design studies (Evaluation of the suitability of welded manufacturing to design and welding performance classes according to EN 15085-3 standard)
• Commissioning (conducting various structural analyzes and dynamic tests and understanding the reproducibility according to EN 15085 standard)
• Production (welding sequence plans, welding procedure specifications, welding procedure qualification studies and welder qualification exams to EN 15085-2 and EN 15085-4 standards)
• Quality (Non-destructive testing according to EN 15085-5 standard and evaluation of errors)

Rail vehicles and rail systems with current identification are used everywhere in the world, especially in urban transportation. The rail systems, which can be transported by thousands of people at the same time and are extremely environmentally friendly compared to land transportation vehicles, consist of vehicles moving on the rails. Trains, trams and subways are always railway cars.

The rail systems are comfortable, fast, reliable, economical and environmentally friendly. Does not cause greenhouse effect in the atmosphere. High efficiency and low energy consumption. It has very low noise level. Percent 40 is operated at a lower cost. Good business strategies and investment costs in a short time.

Necessary conditions for welding of rail system vehicles are defined within the scope of EN 15085 standard. The first drafting of this standard was carried out by the major railway operators in Germany in 1945. These studies are applied between 1997 and 2008 as the DIN 6700 standard. In 2008, it is accepted in all European countries and named as EN 15085.

This standard applies to the welding of metallic materials applied in the manufacture of rail system vehicles and equipment. It is sought that the enterprises carrying out such activities have EN 15085 certificate. Specifically, in the tenders opened, the entity is expected to state that it has made welded manufacturing in accordance with EN 15085 standard.

The EN 15085 certificate proves that the enterprise provides the appropriate level of quality in the production of rail system vehicles and equipment. During the audits performed during the issuance of the certificate and the interim audits after the issuance of the certificate, the studies of the enterprise on the following subjects are proved:

• Perform welding processes in accordance with relevant welding method approvals and welding specifications
• The welding elements are certified according to the relevant classification ranges
• Carrying out welding activities according to the resource planning documents (eg welding sequence plan and welding control plan)
• The company assigns a responsible welding engineer as the resource coordinator for these works and this person can make decisions independently of the production.
• Determination of welding performance class and determination of nondestructive testing requirements and evaluation levels

Welded manufacturing design process is based on EN 15085-3 standard. This is a guide to standard welded joints. This standard contains recommendations for reducing the load on welds. In this way, parts designed under dynamic loads are designed based on high durability. After determining the factors affecting the design, the stress factor and the safety factor, the welding performance class in the standard is determined with these two factors. The resource performance class provides the necessary information for:

• Quality levels for welding defects
• Minimum requirements for nondestructive testing

The most important issue during the commissioning stage of the rail system vehicles is the accessibility to the welding area.

The acceptance limits for welding errors in the production of rail system vehicles are very low. Because these vehicles and equipment work under dynamic loads. An unrecognized error that occurs during welding may grow after a period of time, causing breakage and breakage. In addition, these systems carry people and carry a high risk of human safety. Even the slightest errors detected during production must therefore be compensated immediately.

The type and frequency of resource controls to be performed should be clearly stated in the control plans. Defects detected during these inspections are evaluated and repair decision is made depending on the quality level of the welding and acceptance conditions. Welding checks are generally carried out in three stages: before welding, during welding and after welding.

As a result, it is very important to control the production processes of railway vehicles and equipment. Their operating conditions are very harsh and their lifetime is about 30-35 depending on regular maintenance.

Once the EN 15085 Welded Manufacturing Qualification System standard is established and implemented, the entity may request an EN 15085 certificate by applying to an accredited certification body. In the first step, an audit plan is made and test samples are determined when necessary. Inspection studies are then started.

In the first stage, a preliminary audit is performed over the documentation studies prepared during the system installation. If there are any deficiencies, the second stage of the inspections is completed after completing. At this stage, audits are carried out in the business environment and on the business. Audits are carried out both in the closed areas of the enterprise and in the open construction sites. If there are inappropriate processes identified or deficiencies have been identified at the checkpoints, time is required for correcting them.

During these audits, it is also observed whether the Welded Manufacturing Qualification System applied in the enterprise is undertaken by the top management, whether the standard applies to all requirements in the enterprise, whether the employees adopt the system requirements and whether the documented business processes are followed.

After the audits are completed, a report is prepared by the auditors and submitted to the management of the certification body. If the certification body decides that the quality requirements of the standard are met in the manufacturing activities of the enterprise taking into consideration the results of this report, it shall issue EN 15085 certificate and deliver it to the enterprise.

The most serious problem in welded manufacturing is that it is difficult to detect errors. A small part of the defect in the finished products is determined by non-destructive testing methods. However, most of the defects that will affect the product quality are determined only by destructive inspection methods. Naturally, destructive inspection methods are not possible in the production of railway vehicles and equipment. If these are to be inspected by non-destructive testing methods, it will not be entirely possible to determine that the welding work meets the desired durability and quality requirements.

For these reasons, processes are of great importance. Product quality must be ensured at the design and production stages and all processes must be controlled with an effective quality system. Only then can the welding work be trusted and ensure that it is error-free. Increasing product quality and saving costs depend on it. In this respect, it is necessary to apply EN 15085 standard conditions in detail.

Increased productivity in the welded manufacturing sector, quality assurance and reliable welded structures depend on the preparation of appropriate processes and the application of appropriate welding methods. All stages of welded manufacturing must be effectively controlled to ensure quality production by the enterprises.

TS EN 15085-2 standard (Railway applications - Welding of railway vehicles and components - Part 2: Quality characteristics and certification of welding manufacturers) are classified based on four different certification levels:

• CL1: The welding performance class of welding joints applies to enterprises producing rail vehicles and welded parts from A to D.
• CL2: The welding performance class of weld joints is applied to enterprises producing rail vehicles and welded parts from C2 to D.
• CL3: Applies to enterprises producing railway vehicles and welded parts with weld performance class D of weld joints.
• CL4: Covers manufacturers who buy or sell the design of railway vehicles.

Source performance classes are as follows:

• CP A: Only for fully penetrating and easily accessible welds in production and maintenance.
• CP B1: For high security category. It is applied only to fully penetrating and easily accessible welds in production and maintenance.
• CP B2: For medium security category. Fully permeable welds and volumetric testing are not possible. Surface crack testing should be possible in production and maintenance.
• CP C1: Fully penetrating welds and volumetric testing are not possible. Surface crack testing should be possible in production and maintenance.
• CP C2, C3, D: Applies to all types of welding without special requirements, only visual control is sufficient in production.