Welding method of high manganese steel and 316l dissimilar steel

Abstract

The application discloses a welding method for high manganese steel and 316L dissimilar steel, adopts arc welding, the welding groove of base material is X type, the groove angle is 50-60 DEG, the thickness of groove blunt edge is 1-3 mm, the gap of groove is 1-3 mm; the welding current is 100-140 A, the arc voltage is 20-25 V, the welding speed is 12-17 cm / min, the welding heat input is 8-16 kJ / cm; the interlayer temperature is not more than 100 DEG C, the back welding is carried out after the root cleaning treatment. The weld and the heat affected zone of the method have the impact energy KV2 of not less than 27 J at -196 DEG C, the tensile strength is not less than 480 MPa, the longitudinal face bending d of the welded joint is equal to 4a, 180 DEG is qualified, and the mechanical properties meet the needs of various low-temperature environment use; the process window is appropriate, the operability is strong, special equipment and process conditions are not needed, and the method is suitable for processing of various specifications of thick steel plates and various operation scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to a welding method of high manganese steel and 316L dissimilar steel, in particular to a welding method of high manganese steel and 316L dissimilar steel suitable for ultra-low temperature environment and thick steel plate. BACKGROUND

[0002] High manganese steel is a special steel with excellent low temperature performance, which is mainly used for the construction of LNG storage and transportation facilities, such as transportation ships and land storage tanks. In the construction of high manganese steel LNG storage tank, in addition to the construction of the tank body itself, the tank body also needs to be connected to the feeding pipe, which is generally a 316L stainless steel pipe, so it involves the connection of dissimilar materials. At present, there is no mature method for welding high manganese steel as a tank body with dissimilar steel; at the same time, due to the design characteristics of the structure, automatic welding cannot be realized.

[0003] In the welding process of high manganese steel and 316L dissimilar steel, whether there is a wide welding process window, the joint performance after welding, especially the low temperature impact toughness of the welded joint, needs to consider the influence of the base material dilution, and at the same time avoid the appearance of hardening structure in the weld. SUMMARY

[0004] The purpose of the present application is to provide a welding method of high manganese steel and 316L dissimilar steel suitable for low temperature medium storage and transportation, which aims to solve the problems of poor low temperature mechanical properties of welded joints and narrow welding process window in the existing welding method.

[0005] Technical scheme: The welding method of high manganese steel and 316L dissimilar steel of the present application comprises the following steps:

[0006] (1) Prepare steel plate and welding material; wherein the welding groove of the base material is X-shaped, the groove angle is 50-60°, the groove root thickness is 1-3mm, and the groove gap is 1-3mm;

[0007] (2) Welding: using arc welding, the welding current is 100-140A, the arc voltage is 20-25V, the welding speed is 12-17cm / min, and the welding heat input is 8-16kJ / cm; the interlayer temperature is ≤100℃, and the back welding is treated by cleaning the root before welding.

[0008] Preferably, the thickness of the above-mentioned steel plate is 16-30mm, more preferably 16mm, 20mm and 30mm.

[0009] Preferably, the above-mentioned groove angle is 50°, 55°, 60°; the ratio of the groove face thickness to the groove gap is 0.8:1-1:1; wherein the groove face thickness is most preferably 2-2.5mm, and the groove gap is most preferably 2.5-3mm; specifically, when the groove face thickness is 2mm, the groove gap is 2mm; when the groove face thickness is 2.5mm, the groove gap is 3mm; and when the groove face thickness is 2mm, the groove gap is 2.5mm.

[0010] Preferably, the above-mentioned welding heat input is 8kJ / cm, 12kJ / cm, 16kJ / cm; the interlayer temperature is 35-100℃, more preferably 40-100℃, and most preferably 45-100℃.

[0011] Preferably, the welding current is 100A, 130A, 135A; the arc voltage is 21V, 23V, 24V; and the welding speed is 12-15cm / min, more preferably 12cm / min or 15cm / min.

[0012] No preheating is required before welding, and the back welding needs to be performed after the root cleaning treatment.

[0013] Preferably, the diameter of the welding material is 3.2mm.

[0014] Preferably, the composition of the high manganese steel contains, in mass percentage, C: 0.35%-0.55%, Mn: 22%-26%, Si: 0.10%-0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0%-4.0%, Cu: 0.3%-0.7%, and the balance of Fe and inevitable impurity elements; the yield strength is ≥400MPa, the tensile strength is ≥800-970MPa, the elongation is ≥22%, the impact energy KV2 at -196℃ is ≥27J, and more than 95% of the microstructure is austenite.

[0015] The composition of the welding material contains C: ≤0.04%, Mn: 0.5%-2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0%-25.0%, Ni: 14.0%-16.0%, Mo: 2.0%-3.0%, and the balance of Fe and inevitable impurity elements; the deposited metal has an impact energy KV2 at -196℃ of ≥34J, and the tensile strength of the welding wire is ≥490MPa.

[0016] The composition of 316L stainless steel contains C: ≤0.04%, Mn: 0.50%-2.50%, Si: ≤0.90%, S: ≤0.02%, P: ≤0.03%, Ni: 11.0%-14.0%, Cr: 17.0%-20.0%, Mo: 0.3%-0.7%, Cu: ≤0.75%, the balance of Fe and inevitable impurity elements; the yield strength is ≥177 MPa, the tensile strength is ≥480 MPa, the elongation is ≥40%, and the impact energy KV2 at-196 ℃ is ≥34 J.

[0017] Beneficial effects: compared with the prior art, the present application has the following remarkable advantages:

[0018] 1. The austenite grains in the weld and the heat-affected zone do not obviously grow, which can ensure the mechanical properties, the impact energy KV2 at-196 ℃ is ≥27 J, the tensile strength is ≥480 MPa, the longitudinal face bending d of the welded joint is =4a, and the 180° is qualified, and the mechanical properties meet the needs of use in various low-temperature environments;

[0019] 2. The welding is performed by using the welding rod arc welding, the welding rod has good accessibility, which is conducive to popularization and use; the process window is appropriate, the operability is strong, special equipment and process conditions are not needed, and the processing of various specifications of thick steel plates and various work scenes are suitable. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structural schematic view of a welding groove;

[0021] Figure 2 It is a microstructure structure view of a welded joint. DETAILED DESCRIPTION

[0022] The technical solutions of the present application are further described below in combination with examples.

[0023] Example 1

[0024] A welding process using stainless steel welding material suitable for welding high manganese steel and 316L dissimilar steel includes the following steps:

[0025] The base material is high manganese steel with C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, the balance being Fe and inevitable impurity elements, with yield strength ≥400 MPa, tensile strength ≥800 to 970 MPa, elongation ≥22%, and impact energy KV2 at -196°C ≥27 J, and 316L with C: ≤0.04%, Mn: 0.50% to 2.50%, Si: ≤0.90%, S: ≤0.02%, P: ≤0.03%, Ni: 11.0% to 14.0%, Cr: 17.0% to 20.0%, Mo: 0.3% to 0.7%, Cu: ≤0.75%, the balance being Fe and inevitable impurity elements, with yield strength ≥177 MPa, tensile strength ≥480 MPa, elongation ≥40%, and impact energy KV2 at -196°C ≥34 J, are butt-welded, and the welding test plate combination is 16 mm + 16 mm, with the test plate size being 500 mm (length) x 200 mm (width) x 16 mm (thickness);

[0026] The welding material is a stainless steel electrode with a diameter of Φ3.2 mm, and the deposited metal has an impact energy KV2 at -196°C ≥34 J, and the tensile strength of the welding wire is ≥520 MPa. The chemical composition of the welding material is as follows: C: ≤0.04%, Mn: 0.5% to 2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0% to 25.0%, Ni: 14.0% to 16.0%, Mo: 2.0% to 3.0%, and the balance being Fe and inevitable impurities;

[0027] The groove type is X-type groove, the groove angle is 55°, the bevel is 2 mm, and the groove assembly gap is 2 mm;

[0028] No preheating before welding, and the interlayer temperature is 45 to 100°C; sanding machine is used to clean the root before reverse welding, and the root is metallic luster;

[0029] Arc welding is used, the welding current is 100 A, the arc voltage is 21 V, the welding speed is 15 cm / min, and the welding heat input is 8 kJ / cm.

[0030] Example 2

[0031] A welding process for welding high manganese steel and 316L dissimilar steel using stainless steel welding material includes the following steps:

[0032] The base material is high manganese steel with C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, the balance being Fe and inevitable impurity elements, with yield strength ≥400 MPa, tensile strength ≥800 to 970 MPa, elongation ≥22%, and impact energy KV2 at -196°C ≥27 J, and 316L with C: ≤0.04%, Mn: 0.50% to 2.50%, Si: ≤0.90%, S: ≤0.02%, P: ≤0.03%, Ni: 11.0% to 14.0%, Cr: 17.0% to 20.0%, Mo: 0.3% to 0.7%, Cu: ≤0.75%, the balance being Fe and inevitable impurity elements, with yield strength ≥177 MPa, tensile strength ≥480 MPa, elongation ≥40%, and impact energy KV2 at -196°C ≥34 J, which are butt-welded, and the welding test plate combination is 20 mm + 20 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 20 mm (thickness);

[0033] The welding material is a stainless steel type welding rod with a diameter of Φ3.2 mm, and the deposited metal has an impact energy KV2 at -196°C ≥34 J, and the tensile strength of the welding wire is ≥520 MPa. The chemical composition of the welding rod and the weight percentage are as follows: C: ≤0.04%, Mn: 0.5% to 2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0% to 25.0%, Ni: 14.0% to 16.0%, Mo: 2.0% to 3.0%, and the balance being Fe and inevitable impurities;

[0034] The groove type is X-type groove, the groove angle is 50°, the bevel is 2.5 mm, and the groove assembly gap is 3 mm;

[0035] No preheating before welding, and the interlayer temperature is 40 to 100°C; the back welding is treated by a grinder to remove the root, and the root is metallic luster;

[0036] The welding is carried out by arc welding, the welding current is 130 A, the arc voltage is 23 V, the welding speed is 15 cm / min, and the welding heat input is 12 kJ / cm.

[0037] Example 3

[0038] A welding process for welding high manganese steel and 316L dissimilar steel using stainless steel type welding material includes the following steps:

[0039] The base material is high manganese steel with C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, the balance being Fe and inevitable impurity elements, with yield strength ≥400 MPa, tensile strength ≥800 to 970 MPa, elongation ≥22%, and impact energy KV2 at -196°C ≥27 J, and 316L with C: ≤0.04%, Mn: 0.50% to 2.50%, Si: ≤0.90%, S: ≤0.02%, P: ≤0.03%, Ni: 11.0% to 14.0%, Cr: 17.0% to 20.0%, Mo: 0.3% to 0.7%, Cu: ≤0.75%, the balance being Fe and inevitable impurity elements, with yield strength ≥177 MPa, tensile strength ≥480 MPa, elongation ≥40%, and impact energy KV2 at -196°C ≥34 J, which are butt-welded, and the test plate combination is 30 mm + 30 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 30 mm (thickness);

[0040] The welding material is a stainless steel electrode with a diameter of Φ3.2 mm, and the deposited metal has an impact energy KV2 at -196°C ≥34 J, and the tensile strength of the welding wire is ≥520 MPa. The chemical composition of the welding material is as follows: C: ≤0.04%, Mn: 0.5% to 2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0% to 25.0%, Ni: 14.0% to 16.0%, Mo: 2.0% to 3.0%, and the balance being Fe and inevitable impurities;

[0041] The groove type is X-type groove with a groove angle of 60° and a bevel of 2 mm, and the groove assembly gap is 2 mm;

[0042] No preheating before welding, and the interlayer temperature is 35 to 100°C; sanding machine is used to clean the root before reverse welding, and the root is metallic luster;

[0043] Arc welding is used with a welding current of 135 A, an arc voltage of 24 V, a welding speed of 12 cm / min, and a welding heat input of 16 kJ / cm.

[0044] Comparative Example 1

[0045] A welding process for welding high manganese steel and 316L dissimilar steel using stainless steel welding material includes the following steps:

[0046] The base material is high manganese steel with C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, the balance being Fe and inevitable impurity elements, with yield strength ≥400 MPa, tensile strength ≥800 to 970 MPa, elongation ≥22%, and impact energy KV2 at -196°C ≥27 J, and 316L with C: ≤0.04%, Mn: 0.50% to 2.50%, Si: ≤0.90%, S: ≤0.02%, P: ≤0.03%, Ni: 11.0% to 14.0%, Cr: 17.0% to 20.0%, Mo: 0.3% to 0.7%, Cu: ≤0.75%, the balance being Fe and inevitable impurity elements, with yield strength ≥177 MPa, tensile strength ≥480 MPa, elongation ≥40%, and impact energy KV2 at -196°C ≥34 J, are butt-welded, and the welding test plate combination is 30 mm + 30 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 30 mm (thickness);

[0047] The welding material is a stainless steel electrode with a diameter of Φ 3.2 mm, and the deposited metal has impact energy KV2 at -196°C ≥34 J, and the tensile strength of the welding wire is ≥520 MPa. The chemical composition of the welding electrode and the weight percentage are as follows: C: ≤0.04%, Mn: 0.5% to 2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0% to 25.0%, Ni: 14.0% to 16.0%, Mo: 2.0% to 3.0%, and the balance being Fe and inevitable impurities;

[0048] The groove type is X-type groove, the groove angle is 60°, the bevel is 2 mm, and the groove assembly gap is 2.5 mm;

[0049] No preheating before welding, and the interlayer temperature is 35 to 100°C; the back welding is treated by a grinder to remove the root, and the root is metallic luster;

[0050] The electrode arc welding is adopted, the welding current is 140 A, the arc voltage is 24 V, the welding speed is 11 cm / min, and the welding heat input is 18 kJ / cm.

[0051] Example 4

[0052] The high manganese steel and 316L dissimilar steel were welded by the welding method of the above-mentioned examples 1-3 and comparative example 1, and the mechanical properties of the welded joints were detected according to GB / T 2651-2008, GB / T 2653-2008 and GB / T 2650-2008. The impact, tensile and bending properties of the welded joints are shown in Table 1.

[0053] Table 1. Impact properties of the welded joints

[0054]

[0055] Table 2. Tensile and side bending properties of the welded joints

[0056]

[0057] From Table 1-Table 2 and Figure 2 It can be seen that the comprehensive mechanical properties of the welded joints of the welding method of examples 1-3 are excellent, the austenite grains in the weld and the heat affected zone are not obviously increased, and the mechanical properties can be ensured. The impact energy KV2 of the weld and the heat affected zone at-196℃ is ≥27J, the tensile strength (Rm) is ≥680MPa, the longitudinal face bending d of the welded joint is =4a, and 180° is qualified. However, the impact energy KV2 of the weld of the welding method of comparative example 1 at-196℃ is <27J, which does not meet the requirements. With the increase of heat input, the high temperature residence time is long, and the overheating degree of the heat affected zone is large, which leads to the decrease of impact toughness, which shows that the welding parameters of the high manganese steel and the 316L dissimilar steel should not be too large. The stainless steel electrode is used for welding in the present application, the welding current is 100-140A, the arc voltage is 20-25V, the welding speed is 12-17cm / min, and the welding heat input is controlled in 8-16kJ / cm, which are all the preferred parameter conditions.

Claims

1. A welding method of high manganese steel and 316L dissimilar steel, characterized by, The method comprises the following steps: (1) preparing a base material and a welding material; wherein the base material is a steel plate, the welding groove of the base material is X-shaped, the groove angle is 50-60°, the groove land thickness is 1-3 mm, and the groove gap is 1-3 mm; (2) welding: adopting arc welding, the welding current is 100-140 A, the arc voltage is 20-25 V, the welding speed is 12-17 cm / min, the welding heat input is 8-16 kJ / cm, and the interlayer temperature is ≤100℃; the back welding is subjected to a cleaning treatment before welding; the components of the high manganese steel base material comprise, in percentage by mass, C: 0.35%-0.55%, Mn: 22%-26%, Si: 0.10%-0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0%-4.0%, Cu: 0.3%-0.7%, and the balance of Fe and inevitable impurity elements; the components of the welding material comprise, in percentage by mass, C: ≤0.04%, Mn: 0.5%-2.5%, Si: ≤1.00%, S: ≤0.03%, P: ≤0.03%, Cr: 21.0%-25.0%, Ni: 14.0%-16.0%, Mo: 2.0%-3.0%, and the balance of Fe and inevitable impurity elements.

2. The welding method according to claim 1, characterized in that, The steel plate has a thickness of 16-30 mm.

3. The welding method of claim 1, wherein, The ratio of the groove land thickness to the groove gap is 0.8:1-1:

1.

4. The welding method according to claim 3, characterized in that, The groove land thickness is 2-2.5 mm, and the groove gap is 2.5-3 mm.

5. The welding method of claim 1, wherein, The welding speed is 12-15 cm / min.

6. The welding method of claim 1, wherein, The interlayer temperature is 35-100℃.

7. The welding method of claim 6, wherein, The interlayer temperature is 40-100℃.

8. The welding method of claim 1, wherein, The diameter of the welding material is 3.2 mm.

Images