Corrosion and Stainless Steel in Wagon Maintenance

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Questions and Answers

What type of machine should not be used for cutting IRS M-44 steel panels?

Shearing machine

Band saw

Oxy-cutting machine (correct)

Plasma cutting machine

Which component requires special attention during inspection for possible corrosion?

Side wall stanchions (correct)

Brake system

Wagon wheels

Coupling mechanism

What is the recommended action if a component is found to be corroded and beyond repair?

Replace it (correct)

Repaint the component

Repair it according to maintenance manual

Ignore it

When inspecting SS wagons, which area is NOT mentioned as a vulnerable member?

Lifting lugs Signup and view all the answers

Which of the following is NOT mentioned as a part of the maintenance activities in SS wagons?

Painting Signup and view all the answers

What thickness of steel can be cut using a guillotine machine according to the guidelines?

Up to 16 mm Signup and view all the answers

Which class of welding electrodes is necessary according to the guidelines?

As per RDSO specification No.G-72 Signup and view all the answers

What is the primary reason for using low welding currents when working with stainless steel?

To minimize heat input and reduce distortions Signup and view all the answers

Which of the following practices should be avoided when welding stainless steel?

Weaving the electrode while welding Signup and view all the answers

What is the recommended action after finishing a weld to prevent crater cracks?

Lift the electrode slowly and fill the crater Signup and view all the answers

Prior to welding, what must be done to the surface area around the weld zone?

Clean it of all contaminants and dust Signup and view all the answers

Which of the following statements about weldability issues in stainless steel is true?

Reducing heat input is essential, and no preheating should be given Signup and view all the answers

What type of electrodes should be used for welding IRS M-44 material?

MMAW electrodes approved under class M1 Signup and view all the answers

What diameter of MMAW electrodes may be used based on the thickness of the plate?

2.5 mm to 4.0 mm Signup and view all the answers

What is the recommended re-drying temperature and duration for the electrodes?

150°C for at least one hour Signup and view all the answers

What edge preparation standard should be followed for welding joints?

IS: 9595 Signup and view all the answers

What method can be used to remove discoloration from the cut edge of thin plates?

Grinding or stainless steel wire brushing Signup and view all the answers

Which parameters should be adhered to while procuring electrodes and filler wires?

IS code and manufacturers recommendations Signup and view all the answers

What is the maximum thickness that portable plasma cutting machines can cut?

16mm Signup and view all the answers

What should be ensured about welders performing welding on stainless steel wagons?

They must be certified as adequately skilled Signup and view all the answers

Which gas is considered the most economical for cutting?

Oxygen-free nitrogen Signup and view all the answers

What general guideline should be followed when welding dissimilar metals?

Minimize heat input to restrict diffusion Signup and view all the answers

What should be done to edges cut by arc-air gouging before further fabrication?

Grind back to 2mm to remove heat affected zone Signup and view all the answers

What type of filler materials should be used when welding dissimilar steels?

Compatible filler materials for both steels Signup and view all the answers

Which type of abrasive disc should be used for cutting?

Dedicated discs only Signup and view all the answers

Which class is required for MIG/MAG welding filler wires used with IRS M-44 material?

Class VI Signup and view all the answers

What is essential after powder cutting to ensure edge quality?

Grind back edges 2-4 mm Signup and view all the answers

Which gas mixture is often used for a cleaner cut?

Argon or argon-hydrogen mixtures Signup and view all the answers

What is a recommended cooling/lubrication method when using abrasive cut-off wheels?

Water soluble oil Signup and view all the answers

What happens to edges not subsequently welded after arc-air gouging?

They must be de-scaled and passivated Signup and view all the answers

What type of abrasive discs are not recommended for cutting?

Zirconia silicon carbide discs Signup and view all the answers

What is the recommended approach to compensate for greater spring back in IRS:M44 compared to mild steel during bending?

Over-bend the material by 5% Signup and view all the answers

At what temperature should stainless steel members not be heated to avoid changing their chemistry?

1500°C Signup and view all the answers

What should be done if members are severely distorted and straightening is not possible?

Replace the members with similar grade materials Signup and view all the answers

What is a recommended method to prevent edge cracks during bending operations?

Place the cut face on the outside radius of the bend Signup and view all the answers

Which welding processes are applicable for stainless steel repairs?

MIG, TIG, MMAW, Resistance, and laser welding Signup and view all the answers

What factor is crucial to consider due to differences in properties when welding stainless steel compared to mild steel?

Coefficient of linear expansion Signup and view all the answers

What is the effect of not considering the proper order of operations when dealing with thicker plate sections?

It may cause heat affected zone cracking Signup and view all the answers

What should be done to heavily damaged wagon members?

Replace them with similar grade steel Signup and view all the answers

What is typically recommended to achieve effective bending of thicker plates before welding?

Carry out bending operations first Signup and view all the answers

What is the primary concern when welding stainless steel due to its properties?

Increased possibility of heat distortion Signup and view all the answers

What is a primary characteristic that distinguishes stainless steel from carbon steel?

Presence of chromium that forms a passive film Signup and view all the answers

What maintenance issue is particularly associated with the cutting of stainless steel?

The chromium oxide layer formed during cutting causes rough surfaces. Signup and view all the answers

What is a concern when welding ferritic grades of stainless steel?

Maintaining adequate toughness and ductility in the as-welded condition is crucial. Signup and view all the answers

What happens to the surface of ferritic stainless steel when it is heated during cutting?

A chromium-rich oxide forms, which is nearly impossible to cut. Signup and view all the answers

Under which condition should ferritic stainless steels ideally be serviced?

At temperatures below 750°F to prevent embrittling phases. Signup and view all the answers

What effect does welding have on ferritic stainless steel if not managed correctly?

It can lead to a decrease in toughness and ductility. Signup and view all the answers

What type of repairs may be particularly challenging with stainless steel due to its properties?

Welding dissimilar metals due to differing properties. Signup and view all the answers

What must be done to the edges produced by powder cutting before further fabrication?

They must be ground back approximately 2-4 mm. Signup and view all the answers

Which of the following gases is NOT typically mentioned as a suitable cutting gas?

Carbon monoxide Signup and view all the answers

What type of cooling or lubrication method is recommended for abrasive cut-off wheels?

Water soluble oil. Signup and view all the answers

Which statement accurately reflects a requirement after arc-air gouging?

All cut edges must be ground back approximately 2mm. Signup and view all the answers

Which type of abrasive disc is not recommended for cutting during the discussed processes?

Zirconia silicon carbide discs. Signup and view all the answers

Which of the following locations requires particular inspection attention to determine if there are cracks or corrosion?

All of the above locations Signup and view all the answers

When cutting IRSM-44, which method is explicitly advised against?

Oxy-cutting Signup and view all the answers

What should be the action if a component is corroded and thought to be irreparable?

Replace it based on condition assessment Signup and view all the answers

What should be the thickness limitation for using a guillotine machine for cutting steel?

16 mm Signup and view all the answers

Which of the following components is NOT considered a vulnerable member during inspection?

Brake shoes Signup and view all the answers

For repairing stainless steel wagons, which welding process is NOT typically applicable?

Spot welding Signup and view all the answers

What is the primary purpose of maintaining a consistent inspection policy for SS wagon underframes?

To mitigate operational disruptions Signup and view all the answers

Which of the following actions should NOT be taken when repairing or maintaining stainless steel wagons?

Overheating stainless steel surfaces Signup and view all the answers

What kind of material should be used when dealing with the cutting of delicate edge sections of stainless steel parts?

Plasma cutter Signup and view all the answers

What reduction in maximum shear capacity should be applied when cutting IRS:M44 steel?

30-40% Signup and view all the answers

What is the primary cause of shear breaks during the cutting process?

High cutting speeds and inadequate blade clearance Signup and view all the answers

Which material is recommended for shear blades used to cut IRS:M44 and stainless steel?

High carbon-high chromium tool steel Signup and view all the answers

What should be done to avoid mild steel contamination when cutting IRS:M44?

Wipe the blade and hold down pads free of mild steel particles Signup and view all the answers

What happens to burnish and burr heights as blade dullness increases?

They increase Signup and view all the answers

What should be the recommended clearance setting for a plate thickness of 10mm?

0.25 mm Signup and view all the answers

What should be reduced by up to 20% to help prevent shear breaks of thick plates?

Shearing speeds Signup and view all the answers

Why can IRS:M44 not be cut using a conventional oxy-acetylene torch?

It contains high chromium content Signup and view all the answers

What indicates that shear blades need sharpening?

The blades produce a high level of burr on the cut edge Signup and view all the answers

What is the effect of fast cutting speeds on the properties of the material when plasma cutting IRS:M44?

It minimizes the effect on material properties Signup and view all the answers

Which of the following is a prerequisite for using MMAW electrodes on IRS M-44 material?

Electrodes must be approved under class M1 as per IRS M-28-02. Signup and view all the answers

What is the primary benefit of using small diameter electrodes during the welding of dissimilar metals?

Decreased molten pool size. Signup and view all the answers

What should be ensured about the fillers and electrodes used for welding on stainless steel wagons?

They must be compatible with the materials being welded. Signup and view all the answers

Which statement about the certification of welders for stainless steel wagons is accurate?

Only tested and certified welders should be assigned to stainless steel welding tasks. Signup and view all the answers

What is the recommended action for electrodes with regards to storage before use?

They must be kept dry and at a temperature around 150°C. Signup and view all the answers

What is the implication of not adhering to proper edge preparation standards before welding?

Higher likelihood of joint failure due to improper fit-up. Signup and view all the answers

Which of the following practices is critical when welding IRS M-44 to IRS M-41 material?

Employing low welding currents to minimize dilution. Signup and view all the answers

What is a key consideration when selecting the welding parameters such as current and voltage?

They should follow IS code and manufacturer recommendations. Signup and view all the answers

What is the significance of using RDSO approved sources for electrodes and fillers?

They ensure quality and compatibility with standards. Signup and view all the answers

During the welding process, which of the following practices should be avoided?

Using improper filler material for the steel being joined. Signup and view all the answers

Study Notes

Introduction

Corrosion is the biggest challenge for wagon service life
Moisture, air, high temperature, repair practices, and incorrect surface protection cause corrosion
Selecting corrosion-resistant raw materials is crucial for wagon fabrication
Factors to consider include weldability, formability, availability, and cost
Ferritic grade stainless steel (SS) is now used in some wagons
Maintenance of SS wagons has unique issues including cutting, welding, and joining different metal types

Stainless Steel Peculiarities

Stainless steel differs from carbon steel due to chromium content
Chromium promotes the formation of a protective chromium oxide layer preventing further corrosion
Corrosion-resistant raw materials reduce corrosion in wagons
Oxy-cutting is unsuitable for stainless steel due to the high melting point of chromium oxide
Ferritic stainless steels have service temperature limits below 750°F (400°C) due to embrittling phases

Maintenance of SS Wagons Overview

RDSO has introduced SS in new wagons (BOXNHL, BOXNLW, BOXNR, BCNHL)
These wagons are similar in design to existing BOXN/BCNA wagons
Maintenance procedures of new wagons are similar, but cutting, straightening, and welding procedures are different from plain carbon steel wagons
Corroded/damaged components must be replaced with the same grade of steel

Facilities for SS Wagon Maintenance

Freight yard, sick line, and depot/workshops are vital
Required facilities: MIG/MAG welding sets, DC Arc welding rectifiers, portable plasma cutting machines, consumables for plasma machines, and welding electrodes
Specific facility numbers (e.g., 2 nos., 02 nos, 03 nos) are listed

Maintenance Activities in SS Wagons

Inspection of undercarriage and body structures is essential for cracks, bends, damage, and corrosion.
Vulnerable areas include sole bars, side walls, stanchions, floor plates, head stocks, corner, and end stanchions, and top copings
Cutting techniques: guillotining, plasma cutting (for thinner materials), and abrasive cutting (for limited cutting lengths) are discussed
Straightening procedures are outlined for both manual and hydraulic methods.
Welding procedures: considerations for edge cracks and stress concentrations are highlighed, and welding parameters are recommended
Replacement of severely damaged components

Surface Preparation & Painting

Surface preparation methods and standards for underframes and wagon bodies: degreasing with solvents (e.g., low aromatic grade)
Painting specifications and general guidelines follow standard specifications
Specific requirements for different components (e.g., bogies, couplers, air brake equipment) are described

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Description

Explore the critical aspects of corrosion resistance in wagon service life. This quiz delves into the importance of selecting the right materials, specifically ferritic stainless steel, and addresses the unique maintenance challenges associated with these materials. Test your knowledge on factors influencing corrosion and maintenance techniques.